Fundamentals of Veterinary Clinical Pathology 2 Ed - Stockham

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s, ....... L S'ockham, DVM. MS. Diplo"",,,,. American Cou.g. ofV."'rinary Pathologist. (Oinical P:othol· ogy): Prokssor in tho o.partmCeS :and in""'. ISBN.]3: 978-0-S138·0076-9 (:d.k. p"per) ISBN·IO: O-S138·0076-5 (:d.k. p"per) I. V... rirury clinical p"thology. I. Soott. Mid.. el A. (Michoel Abn). 1957- II. Title. [DNu.t: l. Animal Dis....... p"thology. 2. Cliniul LIDo"'OOY Tr called antithrombin Ill), which then inhibiu the activiry of several coagulation factors {including thrombin}. It :oIso forms .n ionic bond with C~". but its major action is through .ntithrombin. {I} Usrd for several .peciallaboratory =ys (such as blood g:as an:olysi.) and can bt used for many clinical cheminty assay> {2} M.jor disadvantages (a) Alters morphologic fe.tures :md staining of lrnkocyt.. {b} Allows dotting:as efh:t. are slowly o""rridd~n by the coagulation system {c} Allows platd" dump' to form

1/ INTRODUCTORY CONCEPTS

7

3. PI.. ma h.. two IIUjor compon~nts. a. Water: .bout 92- 95 % of plasma volume; 100 ml of pl ..1IU contains 92- 95 ml of H,O. b. Solid" about 5-8 % of plasma volume. Most ",lid. ar~ prot~in' on a _ight per volume (w~ightlvolume) basis. Other ",lids are glucose, ure., electrolyte., and other chemicals. 4. G..nerally, the chemicol compo.ition of plasma is very ,imilar to interstitial fluid in moll tissues. Plasma and interstitial fluid are the a tracdlular fluid. , one intraVll5Cll_ lar and one atravascu.lar. D. Serum I. s"rum is the fluid component of blood that i. harvrned after centrifug>tion of. coagulued (clotted) blood sample. As deKribed in Cru.pter 5, the clotting involves platelets .nd coagulation protein,. To 1:"1: the ffillimal .mount of ""rum from the clotted sample, centrifugation should not be ,uned prior to the retraction of the clot (which typically uke. at I.... st 30 min if. clot actiVOltor is not pr=nt in the tube). If samples are centrifuged prior to clot retraction, some ""rum will be tr~pped in a ",ft fibrin clot. 2. s"rum ha. essentiaUy the 1mle romposition .. pl"'ma except ""rum does not contain most of the coagulation proteim. Th~ Imjor prot~in {on. weight/volume b",is} that is .bsent in ""rum but present in plasma is fibrinogen. 3. During the clotting process, substance. rel=ed from "d is .her the analyte roncen_ trations in ""rum. For aample. platdets rel......, K+, and thu. ",rum [K+] is greater than pl .. m. [K+] (..,. Chapter 9). [I.

Urine Sampl~s A. Other than blood, urine is the most common sample .nalyzed by laboratory """'ys. AI with blood, urine must be collected and processed properly", that the =y reruh, reflect the true composition of the product of the urinary system. B. To prevent .nifactual changes in urine, it ,hould be processed soon .fter collection. Gen~ral guidelines for the collection and processing of urine for routine .nal)"'e5 are d=ribed in Cru.pter 8.

Ill.

Other Body Fluid £amples A. Pleural fluid. peritoneal fluid, synovia, and cerdJrospinai fluid samples are collected to characterize body cavity effusiom, joint di"".,e., and central nervou, system dilOrder.'l, respectivdy. B. The processing and ru.ndling of covitary fluid. are deKrib.d in Cru.pter 19.

MAJOR lYPES OF lABORATORY ASSAYS I.

M.ny laboratory tests or assay. involvt the an.lyli. of body fluid. (blood, ""rum, plasma, urine, peritonral fluid, pl~ural fluid, cerebrospinal fluid, and .ynovia), tissue 1mlples, or feces. Most clinicall. boratory procedure, fall into one of thrtt large groups (aamples follow .ubdivi,iom); IIUny procedures rould be cl.... ified into more than one group. A. Clinical hematology assays: Most assaY' are completed on whole blood sample •. I. Quantitation of cell concentrations in blood: total leukocyte concentration {count}, erythrocyte concentration, and platelet concentration

B

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY 2 s"miqlLOmitation of cdl con~mrations: ",lculata! abwJuu J.ukocyu coIIOning "'mlu from additions or mbtractioll! that use two or more numbt" with appropriate signifialm figu",". th~ final calmlatal r~.ult should havr no more significant figures than th~ numbtr{s} with th~ f.west signifialm figures. For 1.23 + 2.4 = 3.63. the sum should bt ",]>Onal as 3.6.

II.

[t is f"' 1.2 X 10' 3. 1145 --> 1.1 x 10'

Ill.

How many significam figures.", in a numbtr? s." T.bl. 1.2.

[v.

U.lly will not ~ d",,,,as.d. and thus the dog i, not initially .nemic. Mt.. fluid mifu resto .. plasma volume. the dog will have ftwu erythrocyt.. in iu body and a low.. erythrocyte ronet.

..".'""'-, .-'.'-

.-' .,,-, -, • --,-, ..-. -, "'-, -, .-' -, " -.' .'" ........

~-

AIOO . ......

l\-HydoOI)l>'",...' ocire .. nt the refer~n"" population 4. Rifrrmu !!dlur. • value {result} obtainM by oburvalion or m~asurem~nt of. panicular ,ubstan"", in a ref~rencr individual 5. Rifrrmu dhtriburion: Ih. distribution of r~f~ren"'" value>, which i. not n=sarily Gaussian {a kll.,haprd curve} 6. Rifrrmu limitr: the lowes{ value {Iowa ,ifnmu limit} and the highest value {upp" "fi,au:r limit} of the rrftren"'" interval, a. derivM from a ref.rencr dinribution 7. Rifrrmu inurVdl: an int.rval be-iw..:n and including th~ two ref~ren". limi" 8. Qb"""d !!du.r. a value ob,.inM by observation or m.asurement thaI i. to k comp.red to the r~ftren"'" interval C. Use of th~ term "fi,ma mngr i, discouragnl for two r"'Kln,. l. Sutistically, a 'lint' i. th~ differen"" be-iWttn high'" and lowest observations: for example, the r:mge i. 40 if th~ high'" observation wa.< 50 and Ihe lowest wa.< 10.

1/ INTRODUCTORY CONCEPTS

17

2. Some comid" a ranu to indude all m.-amr the values betw..,n two "f."ncr limit .. D. Using the t"m. nCrmIll and "bnDrmIll to de",rib. laboratory test result, am b. mi,le"". ifll: and i, discouragffi. I. A l.boratory ..suit con b. WRI but niH rdlttl a pathologic proct:M. For aample, • strum sodium concrntration that i. WRJ in a ddtydratItion. A brtwun-aJ.kl} CV r~presents th. random error within one run of the assay plw th. error from additional run, of th. assay by wing th. sam. sampl •. The within_ass», CV wiU be mtaller th an th. bet~n_assay CV. dini",l rdevane;., of an assay'_ CV i, deurminal by many factors. If critical dini",l da:isions are made when changes in an analyt" cone;.,ntra_ tion ar~ minimal, th.n the .....y must have a very low CV {high pra:i,ionj. Otherwise, th. diagnostician would not know if th. chIDge in analyte cone;.,ntration is due to a tru~ change that occurm:! in the animal or if the ch ange rq>resenu aruolytiml ~rror. An """y' _ CV wiU typically vary with the analyte·, con"'ntration. High~r CV valu.. may be found at the lower and up~r limiu of the .....y', IDalytiml range. Within th. analytical range, CV values are typimlly higher at th. lower analyte ron",mration, kause CV values are exp=W .., ~rcentag ... (a) If ID assay has a CV of to % ~t all rone;.,ntrations, then the .... y', nandard d~iation would be 0.1 mgldL at an analyt~ cone;.,ntration of I mgldL, I mgldL at an analyte concentration of 10 mgldL, 10 mgldL at an analyte cone;.,ntration of 100 mgldL, etc. Depending on the analyt. and th~ amount of biologic variation, a CV of 10 % am be completdy unaccq>tabl~ aruolyticaJ variation or be very a.c 13,txXl/j.IL to bt rdi.bly

oonsid,,«1 a biologic chang, The ..fore, for th~ strum gluco ... a .... y to ~ clinically valuable, its '=pcabl. random onor can ~ largtr thall tho ralldom .nor of the .. rum Na+ :way, B, Westgard rules. James 0, Wmgard, Ph,D" is • leader in tho fidd of quality :wurance progr.ms for clinical laboratories, H e has d.vdop«l a system that i. desigll.d to da::ide whether an =y'. run .ite npt.im th~ k." concepts {http://www,wostgard, rom}, L A quality as.mrance program should ~ d •• ignffl '" that it detects analytical erron that llliIy ~ of clinical significallce, All measuremellts colltain erron, and tho two IlliIjor types are random error and S)"tematic «ror, Random error i, cu m by facton that randomly affect tho meamrements, such as vari ations ill disptnsffl ""lum. of rea!:"m or umpl~, SysullliItic ~rror is a rq>roduciblo inaccuracy that will ronsistently muh in value, that are too high or too low, Th~ Westgard system is d .. igllffl to detect both types of erron, 2, W'..gard ",k, a", a stries of rules that are appliffl systematically, oith~r sillgly or ill combinatiom," This >ystem i, appliffl to tho results ob[ained for control ... mples that a", analyzed roncurremly with pati~m samples, In his abbreviation >yn~m, "s" , cands for ,candard devi ation, a, I,. rule: A rull is rrjecud when a .ingle control m~asurem~m nettds the m~at1 plu, ls or the m ....11 minus ls of pr.vious control sample values, or it .. rves :as a warning system [0 illitiat~ additiollal inspection of control data. b, I" rule: A rull is .. jectffl when a .ingle control m~asurem~m nettds the m~at1 plus 3s or the m ....11 minus 3, of pr.vious rontrol ,ample values, This rul~ is primarily ... nsitivt to random ~rror,

1/ INTRODUCTORY CONCEPTS

3.

4.

5.

6.

27

e. 2,. rul~ A rull is ..j=a! wh~1I two colI!«mive comrol m~asur~ments nettr.ble random .nalytica.l error. The less impr«ise the ''''''y is, the mo .. likdy it is that. high or low control ... mple v:due will truly indicate a problem with [he assay and the I.... stringtable). If, b.saI on knowl~ of biologic variations, wr imerpret two v:du .. that ..e within to mgldL of ...ch other a[ a d",ision threshold to be the same. then we will colI!id.. such error as acceptable or .Jlov,able. Thu., the allowable total error (fEJ for .n assay is 10 mgldL a[ a d«i.ion [hreshold. Erron of [hat magnitud~ or less will not .ff"'t interpretation of the results. TE,. must be d~termillM at dinica.l d",isioll thresholds, the values a[ which d",isiolls about the p....llce or ab",n"" of diseaR are made.

2B

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

'" '00 ,,-

t< uulyzM with .,m .., of p.tient umpLes, .00 ,esults of .:och control . oluno ... ar< pLotted in .. par ... u..y-Jrnnings oontrol cbar"'. For other ....Y'. rontrol solutions might b. rnalyud with eadt shift (•. g., iV R&.uIIs of sa"", method 00 diffemol instruments (n • 19-111) _ R&.utts of sarno method 00 oa"", instrumool(n. 12- 15) Fig. 1.5. Resul", from umilar:and differ.nt .. soy mrrow rang point, fallon one side of the identity line. then th~ relationship ~ttn the two methods may not be linear. D. Kapp. >g1"ttment {Fig. l.8} as l. Thi, method can be used wh.n laboratory result, are in a categorical scale 1+. 2+. 3+. and 4+ or trace. mild. mod~rate. and marked. A 2+ value may not be twi", that of a 1+. and a 4+ may not be twic. the value of a 2+. 2. The calculated kappa value provid.. a guide to the degree of agrttment. The size or degree of di~""'ment is not considered with the standard kappa m..rhod. but it is with the weighted kappa method.

rum

Comparison of Urine Heme Reactions: Reneclance Photometric versus Visual Grading

H > " 0

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""G"~v"

I ""!Jat.....

R.m"'ctanC8

, ",

,~

"" 0 0 0

, , ",

, ,, ,

ic Grltdinll

0

0 0

0 0

0

Wetghted kappa value. 0.78 Interpretation guidelines

0.20 ~ 0.39

F";r

0.OO ~ 0.19

Poor

, I , • 0 0 0

,

Fig. 1.8. K.pp •..,.groement d ... for urin< he"", ,u"tion. Aft .. dipping the ruction pad in tOO u,in< ''''''ple.. the color cltrn~ in a horne-,e:ote 2 Di:ognostic mppon =1 b. .vail.bl. &om nteri",,'Y clinical pamoJogim in the laboratory. 3. Ref.ren"" illt.rv:.!, should b. .ppropriat. for the .~j ... 4. Mon laboratori., have a qu:dity m~m.nt .yn.m in pi""", to hdp enSUf. qu:dity results. Th •• yn.m oli.n includ.. proficiency testing by an at.rnal group such that pftrs. 5. Many more di.gnonic assays ... typically available than "r .vailabl. in .n in_hou .. laboratory. 6. Th. eost for sample analysi. i, more clnrly determined and thll'l can b. chargffi to th. e1i.m on ...mpl~by_sampl. basi,. B. Di..dvantago' l. Not .Jl.n:olyt..." st.bl•• nd thus ",m. dff.riorat. during shipm.nt. Som•• n:olytes requi .. sp«ial shipping. 2. Turnaround time, V:lf}' with location: wme ... av.ilable the .. me day, .nd most a.. a..... il.bl. th. next day ucept for .peci:ol um. Somelaboratorie. off.. couri....",ice and n:JUlu "ported via fax ma.chin.. or e_mail.

,,,,,,,It•.

[v.

Laboratory in loc:ol human hospit:ol A. An adv.mage i, that turnaround times am be within hours. B. Di..dvantago' l. Quality ..f..ence interval, fur veterinary .ampl.. may not be establiohed by the laboratory. 2. )"say mffhod, may not be appropriate for veterinary sampl ... 3. Technician, .nd technologist, may not be trained to rorreccly idemity .peci.. variation, or di,..,..." that are unique to veterinary sampl... 4. Pathologists who specialize: in human pati.nts frequ.ntly a" very int.... t.d in hdping, but lack the training in th. di"'.... of domncic animal, .nd variation! lttn in veterinary sampl... 5. Th. f= charged by laboratories may be "latively high. C. Testing in local laboratori.. that .peci:oliu in human m.dicin. should gen.rally be avoided.

EVAlUATING AND VALIDATING U.BORATORY METHODS" I.

Re"",ns for t< no FN ""ulu. a n•• ""'ision tbmbold is at tho high.1t v:;d"" fOund in rio. .rumrn without tbo ru.e.... • Tbe di.gnostic ..",itivity would I>< poor (.bout 60 '10) b.caw. tb.r. ace ",I.. ivoly mrny FN , ....1".

wt:o

• • • •

Tn. di.gnostic sp< 100 % b.au.. ilion :or< no FP r.",la. Tn. di.gnostic :oco.u:ocy "fOUld I>< poo' b.a.,.. of tho. mmy FN ,.,..,1". Tn. PV(+).....,uId be 100 % b.a .... tho."':or< no FP ""ula. Tn. PV(- ).....,uId be poo' bee..,.. tho. .. "'. mrny FN , .. ultl.

C. TI>< ""'ision tb,.,hold is 1t. ronc:mu •• a positive reru.lt from a neg .. ive result? Extentivo evaluation of.n atS1)' i. somst btc.ust 27 % of ""limn with th. di ..= h;,,,,, valu .. of 40 mgldL or I. ... c. This example emphasizes that for many diagnostic tests •• nimah with and without the di"'''''' of inte..st may have the .. me .....y result. 2. Anoth" key concept rdated to this illustration is th . t e.ch ROC curve .. prestnts the resulu obtained from one sampling of the defined popubtions by using on. assay:u it compares to one gold nandard. Anoth" sampling ming the same sdection criteria, the same assay, and the same gold nandard probably will not produ"", the ... me ROC curv• . F. F.cton oth" th.n the probability of correctly classifYing .n aninul .. having or not having a di"'''''' can influ. n"", where decision th ... holds "'" ost . blished: I. If the monality rate is very high for a dis ...... that is not treated promptly, the decision thr..mold may be changed 50 that th"e ... few.:r fal .. negative>. 2. If the dist ... is known to cause I"'in or unreasonable discomfon, the decision th ... hold may be ch . nged so that there are few" f. lst negati=. 3. If the tr .... tm. nt i. known to ha"" "",ere .ide effects, the deci.ion thr..mold may be ch anged so that the", are few" f.l", positives. 4. If the fin:mciN on exp"ri~n~ and r...euch. Giv~n th~ int~rloboratory ",rittn ~valuata! in ~~ral ways. I. M.,n h~rd v:.!ue; truly b. comp.ral to mean ",lue; of ",f~ren"" h~rds. When metabolic profiling was first describal. th~ ..f..~n~ int~rval for an a""lyre was defina! as th~ m.... n of its me' n! for r~f.."n~ h~rds. ± 2 sd. How~""r. th~ .. h~rd ",f..en~ inte",:.!, .re not re.dily .",il abl~ beau", of the ex~n .. of te;ting and diffirulti~, id~ntifying ,uitabl~ ref~ren"" h~rd,.

2.

M~.n h~rd

v:.!ue; truly b. comp..ed to an e;tabli,hed expecra! m....n result for the and group of int.... t. For exampl~. it has !>ttn 'ug~ned th .r m.... n urin~ pH ,hould b. 6.0-7.0 in prefre,h row, fa! anions to hdp prevent milk f~~r. A m~.n pH of 6.0-7.0 mpports appropriat~ acidification of th~ group. When the herd·, m.... n ± an un~rtainty int~rval doe. not includ~ 6.0-7.0. a h~rd·. urine pH i, cons.ideral inappropriate. When th~ herd·, me.n valu~ is not 6.0-7.0. but the mean ± un~nainty int~rval o""rlaps thi, tatg"t. the results are cons.id",al bord..line. A 75 % confiden"" int~rval ha, !>ttn mggesta! as a u",ful guid~ for metabolic profiling and a reasonabl~ compromi'" becw",n 95 % confid~n"" and practicality. 3. The !",/"Centage of individual results abo"" or b.low an establi,hed d«i,ion threshold may b. calculata! and compara! to what i. con.sid~ral an a=ptable !",/"Centage of high or low ",lue;. A p"rctntag~ (± un""rtainty int~rval) gr~at .. than th~ a.cctpted p"rctntage 'ignal, a problem. A p"rctntagt and confid~n"" int~rval overlapping with the accq>ted !",/"Centagt is a bord~rline r~.uh. D«ision thresholds may "" "'m~h at artificial in that the ri stimulnr diff... nt;",ion .nd prolif".{ion of B.lymphocyt.. and T .lymphocyt... 2 lymphocyt~, Jeav. lymph nod.. vi dr.rent lymphatic v....d, and .ntt~ to lymph nod~ corti= via .p dT~ .. nt lymph atic """ds. and ",rurn to blood. 2. About 25 % of blood lymphocyt.. ~nt~r lymph nod .. ~ach d"Y through postcapil. lary v~nul... which han uniqu~ tall ~ndothdial edl. and r~tor>. D. Lymphocytes ill oth~r tissu .. I. lymphocyt.. ~migr:lt~ to ti ....... to ""rform functions. Th~r~ thry moy und~rgo blmogtn..i., ~nt~r lymph atic v....d. to mum to blood. or di~ . 2. Lik~ n~utrophih. migr:ltion to tissu .. invol"". lymphocyt~ ch~motaxis .nd bindillg to ~ndothdial cdl ~tors. E. M.jor processel that influ~n'" m~asurw blood lymphocyt~ con"'ntratiollJ I. Production a. Sum cdl prolif~ .. tion and diff~ .. ntiatioll b. BI.. tog~lI ..is 2. Distribution of lymphocyt.. k!w""n th~ CLP and th~ MLP a. Migmioll from blood to lymph nod...nd oth~r tissu~. b. Migmioll from lymph nod .. via ~ff..~nt lymphatic v....d, to blood F. Lymphocyt~ lif. .pall varies from hours to )""'Irs. Monocyt~

IV.

pooh and kinetia A. Monocyt~. and naltrophil. sha.. a common bipot~ntial st~m cdl {CFU.GM} that i• • timul>lw to diff~r~miat~ by inflommatory cytokill". B. Monocyte. dn-dop from mOllobwts and promollocyt... Wh~1I rd~ased from morrow. monocytes distribut~ ~n m..ginatw .nd circulating poot.. C. Lik~ oth~r leukocyt... monocyt .. ~migrat~ to ti ..!U~. aft~r binding to .ndothdial edt.. 011'" in tissu ... monocytes may diff~r~miat. into cdl. of th~ mOllollucl~.r phagocyt~ .ynem: macrophages {including Kupffer edl ••• lvrol.. mocrophagcs. and type A .ynoviocyte.l. microglial edls, or d~lIdritic ",H•. I. Th~ rming ma.croph~ is sometimes callw a histiocyt~ or fin-d macroph~ 2. Delldritic cdls ar~ .ntigen.pr=nting ",lis. Examples includ. the ung~rhans ceUs of the .kin and im..digiming ",lis in lymph nodes.

V.

Eminophil pools .nd kinetics A. Eosinopoi..is is stimulatw by 'J"'Cific medi ator>. illcluding IL-5 {msinophil differ~nti •• tioll f.ctor} and GM·CSF from ma.tion is increased. the di",.,e is causing at l.ast on. of the following: a. Inc",.,ffi production of that ",ll type b. A shift of that ",II t)'~ from a no~ or noncirculating pool to circulating blood c. An incr.....d circulating li£. span of the cdl typkocytes for morphologic abnormalities and record the findings. 2. Microscopic enmination of a nain.d blood film is especially imponant in sick patients .nd Ihose with .bnormal concenlr.tions ofleukocytes. erythrocytes. or plaldeu. o.,fecu found in th. blood cells.", described in Chapters 2-4. F. Staining of blood ceUs I. iWmanoWiky 'taim. which .re the best for staining blood cells. were described by Romanow..ky (1891) as. rombination of eo.in and methylene blue to produce. spectrum of colon from blue to raldi.h orangt'o depending on Ih. pH of the cell·s rontent. a. Wright IMin i. a combination of "".in and oxidized methylene blu •. The oxidized methylene blue nains are call.d /Wi" dytl. b. Other Romanow..ky stains include Giemsa. W,igh,_Gi.msa. and Wright_ Leishman. which are ... rious combinatioru of a7.llrr dyes and "".in. c. Generally when staled or w,itten. "Wright" nain ..f.rs to • Romanow.ky_type stain and not the otiginal W,ighl stain.

mapes.•

62

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY 2. Wh at."" th~ oont~lIIs of sin dye and ,c.in Slructures from ral or pink 10 orang•. 3. T.rms usa! to doscrik colon or staining proptrties a. Nrumphilje: n(urro (n.ilhor alkaline nor acidic) pJu.s phiuc {"loving"j b. E~linqphilk: loves «>sin {.cidic} dre; will'" rw to orang. c. &',ophilic: Joves b.. ic (:dkalin. :md nur.) dy.. ; will k blue to purple d. Azurophilic: Ions ..ure dye; will h.ve a blue to purple to reddish purple to pink oolor dq>l~ r...ctions that produ"" • black pr"'ipitau in tho .. ""II.. Th~ leukocytes (,uinM .nd unsuined) then I"'ss through a beam of tungsten light. and .. nson del"'t increase-d light .bsorban"" (due to stained cdl.) and light scatt~r (due to the ,iu of cdlt). The peroxidase ch:mnd provid.. a [WBC] .nd per""n~ of eosino· phils {3+ peroxida.. J. neutrophil. {2+ p'roxid...}. monocyt .. (1 + peroxidase). lymphocytes (,mall. negative: peroxidas.). and la'l:" unsuined cdb (large. negative: peroxidasr). Because cat rosinophils lack p'roxid....ctivity. they must ~ d ... ifiM by using a special ,uin (ox.:lz.in~ 750) that i, also used for d,,"'ting reticulocyte .. Eosinophilt of lOm~ greyhounds. Gr~at Dan... and other dogs have: low peroxidase .ctivity .nd ar. mi.d ..sifiM as monocyt ••. S."'phih a.. not accuratdy classified in domestic species. b. Basophil channd: By using a diffe .. nt Iy.ing agtnt. "rythnx:yt•• and leukocytes oth~r than basophils {in human umples} .'" IpM. and then the fluid pa!SeS through a lasrr bram. Light scatter is used to diff~ .. ntiate particle sizes (inuct human basophil, ve:nus other ""U nucl.i) and nucl~.r d"nsity or lobularity. Th. b''''phil ch annel provid~s. [WBC] and per""nuges of minimally lobulatM {lymphocyt... monocyt ... immature granulocyt ... and bl>stic ""lls}. basophils (in human sampl..). and polymorphonucl.... r cdls {neutrophils .nd eosinophils}. Conine and fdine b"",phib a.. not delectM by th" basophil ch:mnel. c. If th~ .. are erythrocytes that are wi",:mt to lrsi •• the [WBC] of the peroxidase channel will ~ falsely incr~• ..d. but th" basophil channel [WBC] should ~ .ccurat~. The pr=n"" of nucl~atM ~rythrocytes is suggested if the "polymorpho. nucl~.r ""II" ron""ntration from the basophil channd i. greater th.n the mm of th~ neutrophils .nd eo.inophil con""ntratiom from th" peroxidase rnannd (u""pt in cau. because th"ir eosinophilt lack peroxidase activity). d In cont .... t to th" microlOOpic differ~ntialleukocyt" count. this el~ctronic diff"rential count differentiates thous;ond, of I.... kocytes. and thus sampling "rror is typically not a problem. How"ve:r. th~ el"'tronic methods mun ~ species specific and may not ~ a.ccu .. te when atypical ""lis {•. g.• toxic neutrophils. and r...ctive lymphocytes} a.. pr=nt. Automated differential counts may ~ con· sidered reliable wh"n ""II populatiom are d ... rly >qlaraud as indicated by ""ruin d"finM crit~ri .. D. Quantitative buffy CO>l {QBC} an.lpi,'· {QBC V.tAutor ...d}

""U,

66

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

Butry coat

EryIhrocyt...

Fig. 2.6. Scbem. tic "'p,ostion of ...hoI. blood. G.ntrifug..l forces "'I',..t< II.. compo"""'" of blood into fiv< 1.J"'J'lI (pWIIU, pl.",,,, .. , agr=ulocytes, grrnulocym,:md rryth.rocyt"') b....d on 'Mil r.uti ... densin... Tn. buJJy coat (coml"""'d of pb"Le. 4. Th~ . ccuracy of th~ p"nial leukocyt~ diff,,~mial coulll d.".,nd. on the .milling "':lCIiOIll of the leukocyt.. and their d~",iti ... Atypicol stainillg or d~",itie> will /"l" in most CBC remh., alld thus diff~tug< _ !M cdl oon""ntntion 1. Microsropic and som~ d«tronic mrtho,j, drt~rmin. [WBC] by counting nud.atM ""US or nucl~i {.ith~r ofleukocyt.. or nRBCs}. By thosr m",hod. , a mnsurM [WBC] rrprosrncs th. sum of nud"'!M crlJ concrntration, (leukocytrs + nRBCs),

2/ LEUKOCYTES

69

ob",,,,ffi during th~ n:lmination of th~ blood film. thr~

oorrected [WBC) = m=ured [WBC) X Exampl~:

"',.,-:;:c"""':;;;;""'" "" 100 + ffnRBCIIOOWBC

(2·1.1

m. A. Neutropbil kinNtrophi~a: N ... trophilia occurs ~ oftb • •bift of neutropbils from tl>< MNP to th. CNP. F. Chronic m)""Loid leukemia: Neutrophili. 0Clory mrdi>lors. When th~

75

2/ LEUKOCYTES

rat~ of namophil rd~~", from marrow is grrat~r than th~ rat< of neutrophil margin.rion and ~migr>!ion to tissu .., • neutrophilia develops. b, Chronic indirectly rd'",. to the duration of the di"", .. ; the infLommatory process has ~r:sistM long enough to r.sult in granulocytic hYP"rplasia, c, Wh~n.n animal has a chronic inflammatory neutrophilia, oth" lrukocyt~ abnormaliti.. may include lymphocyto.i. (with or without reactive lymphocyt..), monocytosi., ..,sinophil"" I>=>philia, a I.ft shift, ~ right shift, and toxic nrutrophils, 3, Steroid {mess} neutrophili a a, This n.... trophilia r.. uhs from changes crratM by th~ effeet. of endogenou. or nogenom gluroconicoids on n.... trophil kin..riu {Fig, 2,7D}, Although this nrutrophil", is frequently callM a itrN n(urrophi/ill, it mould not be confusM with th~ """iologic (lhifi) nrotroph;{id COUsM by the me,,_indu=l rd.~ .. of catecholamin.., {I} Neutrophil. shift from th~ MNP to the CNP b.cou"" the production of oodh..ion moluW by the chang. in fluid dynamics that mult. from increastd blood How rat., espa;ially in lungs." Nrutrophil :odh..en"" to

endothdi:d cdh =1:'!so be, rffiucffi. " b. Th. m"l:nimd. of neutrophilia =y be, up to cwi", th. URi for canine, «J.uine, and bovine blood, .nd potentially up to 3--4 X URi for a cal kcau .. of. eat'. I"'get MNP. c. It is ,,,,,n most &«J.uently in h.:dthy animal. and mostly in cats. uukocyt< conctntration, mum to ""f".nct illt..""l, relativdy f:m (within .n hour) if the stimulus dj,..p~.rs. d. B«aust th. incrrasnl blood flow "Ie .JUts kinetiC! of olh" l. ukocyte., th.", .150 may be, inn.=pl.,i", lymphopmi. occ",", b.cau.. of y occur duting neutropenic cyel.. and her;old incr ......,. in blood neutrophil concentrations. 6. G_CSF: This may be administered to promote nrutropoiesis, but it wiU also promou monocytopoiesis. B. Monocytopenia: This is difficult to document beau.., healthy domestic mamm>ls may havt rdativtly few blood monocyt ... Monocytopenia i. not con,idered a diagnostic problem.

[v.

Abnormal eosinophil concentmionl A. Eo!inophil", {incr.....ed me• • ured blood eosinophil concentmion} l. Mon eosinophilw .ppe:ir to be reL.ted to eosinophil .nti_inllamm>tory function> or to the .ttraction of eosinophils to ti ... u.. after mast celJ or basophil degranulation. 2 An eosinophil", sugge;ts the po .. ibility of m>ny di..,,,,,, nates (Table 2.12). a. In the hyper",nsitiviry disorders, typically there are clinical .igns associ.red with the involved tissues: for nample, pruritus with II .... bite or naphyloroccal dermatiti •. b. Both internal and extern.l parasit.. are frequently blamed for .n eosinophil"" but many .nim>l. with similar p.rasitic infections do not have an eosinophilia. Per..inent mild eosinophil", is oeinophilic pnrumonili., eosinophilic granuloma complu in Sibtrian huski .. 'UI: eo.inophilic granuloma romplu, =inophilic ~nurili" hyprtal ob5.rvation during n.tural infn:tions. K. T"""pfil= t!'ndii (P1. Ir 21) l. T .chyroilr. of TIJXOpfil""" t!'ndii are rardy found in blood neutrophil, and mono_ cyt .. of dogs and cots with .cur. toxoplasmmis. 2. Thq ..~ mor~ common in mxrophag .. of inf'""tffl ti"" .. (lung .nd intestine).

IY.

Lrukocyte agglutination/aggreg. tion A. CX:casionally, small aggregat .. of 3- 15 l.ukocyt~. are found with th~ body of a wdl_prqmal blood film. Typicolly thq ... mixtures of neutrophil. and small lympho_ cytes with f~·~r .osinophil, and monocyt ... Th.,. should ~ ,uSpuiniud 'amples ...... Wh~n aggrrg.tioll w:as Sttll ill room t~mp'ratu", ,amples but 1I0t ill ""mpl~, ~pt at 37 ·C. th~ lI.utrophil aggrrgatioll was due to an [gM ." C. A major rta'lOn for rrt. neutrophil nuclei h.d 3-11 ddinitin lob., "p,... trd by filoments, and .bout 70 % of nuclei had 7- 10 lobes. Oth.. cas.. han b.en .imil... B. Hypt=gmemation i. not :woci. trd with the common COUIe; of hyptnq;menution; that i., hy~rad .. noconici,m (Cmhing', di ..... ) and aogenous gluroconicoids. The co.,.., of the .yndrome has not bttn det .. min.d. The po"ibility that hy~rsOi. in ",;"iatu".ncytk.....,.;. " (NADPH .. methemoglobin rMuctase). 3. Amino acid. in the globin ch.ins :ore m.imainM in • rrou=:! S{ate by rMuai"" "'action> involving GR and catalase. B. Hgb function (Fig. 10.3) l. Hgb (with F~") tr>nsports 0, from lungs to tissues. In health, Hgb i. ]00 % satur>tro with a, in an ..ial blood. Hgb .. F~ does not tran>pon 0,. 2 Hgb plays two major rol .. in the tr>nsport of CO, from ti HHgb) to r~mo"" the H+, and HCO,- diffuses from the "",Il to the pl:uma. The buffer .. ing of H+ by Hgb f.cilitat .. the additional conversion of CO, to HCO,-. When erythrocytes return to lungs, ,,""tions .re "",ned .nd CO, i. rdeased for expiration. About 70 % of the CO, formed in tissu .. i. tr>nsportro to lungs vi;, this system. b. When CO, diffu ... into erythrocytes, ",me binds with Hgb to form carbamino .. hemoglobin. About 20 % of ch~ CO, formro in ti ....... is tr>nsportal to lungs vi;, this system. C. Hgb synth..is l. This occurs in erythrocyte pr."",. md (3) binding of fow ferrihomo and four globin mok.moglobin . • Hemoglobin d.gr. d.tion in mocroplug .. : In l>..Jth ... ne."", i, 'plit from globin cboins. H."", i, dq;roded to bilirubin. F.'"'. rnd arbon monoxide (CO). The globin cboins "'" dq;r> J>",toining to a eBC are in Chapter 2 (Am/ytiCl.I Principles and Methods, Ket. I).

[I.

Erythrogram A. Morphologic ~"'uatjon

l. A microscopic rvaI",,{ion of suinal erythrocytes is .n imporunt part of the nythrogram, espa;i:dly when .nemia is p,,,,,,m. 2. [n the Morphologic h.tures of Erythrocyt.. stcrion, the clinical .ignificollcr of erythrocytes with abnormal rolol'S, .jus, ,ha!>"" inclusions, or alh" f....tu ... i.

d.""ikd. B. Hcr (synonym, PCV): hnnaro_ ("blood ") -nit {denoting ".qm.tion"} l. Hct is th. pe'''''ntage of blood ""lurne filJal by uythrocytes and th.r.fo .. a m= .. of th. O,-carrying cop3oCity of th~ blood. If th~ .. a", 100 ml of blood with a Hcr of 45 %. then ~rythrocyus occupy 45 mL 2. A Het will accuratdy r~A'""t th~ [RBC] in a blood sampl~ if th~ Mev is WRl. 3. A Het will accuratdy r~A'""t th~ blood [Hgb] in a .ample if th~ MCHC or CHCM is WRI. 4. Unit: vol % (oommonly jun %): and 40 vol % = 0040 {the SI apression is. unitles. decimal fmetion} C. Blood [Hgb] l. Th~ blood [HgbJ is th~ grams of Hgb ~r 100 mL of blood ~ntially all Hgb in blood i. in ~rythrocyu. exscul.. h~moly_ si. cousi"l: h~moglobinemia) or aft.. t... tllYnt with Hgb_~ 0, corriers (e.g. , Oxyglobin). 2. Th~ blood [Hgb] will ac for all ~rythro. cytes in th .... mpl~. 3. Rd.lionship of indiu. a. Brau", th. MCH "'Pr=ms how much Hgb is in .n av,,"C. th~ degr.., of inaccuracy in th~ ~rythrocyte data i. typically low o:erpt wh~n th k.g., CELL_DYN. Bay'" Technicon HI, ADVIA, and Sy.ma) I. Basic principles (0« Chapter 2, especially Fig. 2.5). The flow cytom..cric .. prcu of th~ CEll_DYN ar~ u.std in addition to impfflaner to """l'"'t~ l~ukocyt .. , whege {RP} (som~im .. calla! m;cul~rylr munt) I. Th~ RP is th~ prr""ncag.. of ~rythrocytes th.t "'~ r~ticulocyt ... For a.mpl~. if th,,~ are 10 r~iculocytes prr ](XXl ~rydlfOCyt ... the RP is 1.0 'lb. 2. It is usal to calculate RC or CRP. It indicot~, nonr~nuativ. an~mia if not incrrasa! and ]>.,ionally in animal. without evidena. of hemol",i •. The "gglutinin (a mMana. causing the au/utination) it typically a rold antib~:r. that is, an antibody that has maximal activity at 4- 20"C. 2. The erythrocyte dusters formed by autoagglutination must bc: difftrentiated from lOuiraux, which dassicolly appear as .racks of erythrocytes but con appear as piles or fallen .racks of coins. Wh~n examined macroscopically in • tubc: or as a drop on • slid~, blood containing the au/utin>!ed erythrocytes or rouleaux has • fine to co .... granular .ppearance. 3. One method to difftrentiate au/utination from rouleaux is the saline dilution (di.p.fol< maturing to rrticulocytes. {2} Disorden or conditiom that cau"" inappropriate rubricytosis (a) Marrow dunagffl by n«:tosis. infLommation. endotonmia. hemic or nonhemic nroplasi •• or hypoxia; Nucle.trd erythrocytes gain entranc:r imo m:arrow .inu.., through damagrd sinu""idal endothdium. {b} Extramrdullory hematopoi..i, {esJ>"Cially splenic}; Thi. may :dlow rd.... of ctlls b.fore nuclear extrusion. {c} Splenic contraction; Splenic blood ronuins nude.trd erythrocytes that are oompleting maturation. {d} Splenrctomy; The few nRBCs that are normally rd.....d from marrow at< not· rought" by the spl..,n. (e) In.d poiwning in dogs. ""rhap' the result of damage to marrow "nus.. (/) Bone marrow dpcrasi. in poodles with macrocytmi. (..., Oth.. Nonnropl ..nic Leukocyte Diwrdm. Ket. II. in Chapt" 21"

=""

III.

Erythrocyte oolor A. emlr"{ pallor refers to the pale ""ntr:d region of an erythrocyte that is due to the rdati"" thinness of the area cr ... trd by the cd]", bironcave ,ha"". l. Inc"""",d ""ntral p:dlor is us,",lly indicative ofhypochrom.. ia. 2. Drc""asal ""ntral p:dlor m,",lly indicat.. abnormally .m.ped erythrocyt.. {poikilocytes. including spherocytes}. It is:d"" commonly =n near a blood film·, feath"rd rdge b.ao.us.- of anifact,",l distortion of erythrocyte .ha"". B. A ~if all i, an extremdy pate_staining erythrocyte consining primarily of cdl mem_ brane with only a .mall amount of r.. id,",l ""ripheral cytoplasmic Hgb (Plate 3D). l. Ghost cdls . 1< usually formrd during complement_mrdiatrd intrava5Cular hemolysis. Membrane acrack complexes form membrane por.. through which Hgb leaks out. 2. Ghost cdls may form in vitro as a result of smearing trauma. Thest artifactual ghon cdl. arr often distoned. C. A hypcchromk ")'t/n-gryti i. a poikilocyte with incr ...srd central paUor and more faintly stainrd Hgb than u,,",l {Plate 3E}.

138

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY l. HYJ!«"""",,i/J j. an inc,..,....:! numbtr of hypochromic uythrocytes, which ffi"}' bt

",f\«1ed by a d«r=d MCHC and CHCM if the hypochromic population is luge enough. 2. Hypochromic erythrocytes remit from a da:, raonj intncdJuJ:.r Hgb ronumration. When visually rvid.nt, th~ usually are ..,5Oci ated with F. deficiency. How~.r. hypochrom"'", b>=l on th. MCHC or CHCM alone (without microscopically ,pp",nt hypochromic erythrocyt..) is usu. 3. & rirulocytolu {increased blood Re). like increased polychromasia. i. an imponant indicator of acederat"'" erythropoiesi •. [yo

Erythrocyte organisms A. IdentiJYing features are list"'" in Tabl. 3.5. B. Major .. peets of th. anemias or disord.rs caused by organisms.", includ"'" in the Nonr'l:"n ... tive An.mia and the Hemolytic An.mias KCtions.

v.

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141

stippling must b. difftr~ntiatw from sid~rotic gr:mul.., which a.. mu:dly located in duners. 2, ~philic lIippling is 5«n with r~nemi"" an~mias, esp«iIlly in canl~, but :dso in dogs .nd en" 3, When seen without corresponding polycluom:lSia or reticulocytosis, or in nonane_ mic .nim:d" plumbism is a common cause, eo;pecially in dogs, Lead inhibits the pyrimidine S'_nud..,tid.... cru.t hel", degrade nud..,tid .. in RNA Heinz bodi.. (Plate 4H :md I) ], Hrinz bodin a.. ~regates of d~n.tured Hgb cau...! by oxidatin dam:.ge, 2, H~inz bodi.. are visu:diud with NMB min :lS pal~ blu~, protruding, rounded structu.., associ.tw with ~rythrocyu membran.. , In Wright_stained films, H~inz bodi.. han nearly th~ s;om~ suining featur.. as norm:d Hgb but appear as slightly p:de structures th. t c",at~ membr:me defects or protrud~, Heinz bodi.. nuy deuch from erythrocytes .nd OCCut as free bodi.. in • blood film, 3, Exc;.,pt in cal>, the preseno: of H~inz bodi.. in :m :mim:d with. hemolytic anemia indicates Heinz body hemolysis, Sm:dl single Heinz bodies {diam~t .. .. 0,5 ).lm; ..e the srruollen forms in Pl. te 41} can b. found in the erythrocytes of cats without dinical anemia or h~molysis, Hgb """,Ii (Plate 4J) L The.. are seen occasioruolly in domestic mamm:d erythrocyt.. (induding dogs and cats), but their significano: i, unknown, Some may form in vitro becau .. of s;omple storage ronditions, 2, Hgb electrophoresis has failed to demonstrate abnorm:d Hgb molecul.. in domestic numJrulh that have ru.d Hgb cryllals, Howell-Jolly bodi.. {Pt.", 4K . nd L} L A H~UKll-J~11y IMdy i, a nucl .. r remnant th . t h •• remained free in the cytoplasm after mitmis of.n erythrocyte precursor, The Howell-Jolly body is nuclear materi:d tru.t W:lS not incorporated into. new nudeus, 2, Howell-Jolly bodies can b. found in healthy Jrulmm:d., frequently in cal> and occasion:dly in dogs :md hor ... , The numb.r of Howell-Jolly bodies in blood incr..... during .cederated erythropoiesis .nd also m.y incr.... in Jrulmm:d, with decr .....! splenic function {including aft .. splenectomy}, Refr.ctile anifacts {Pute SA} L Erythrocyte ..fractile anifacts .'" frequently found in stained blood film" Objects are rrfoutik when they chang. from dark to shiny as the focal plane is ch:mgffi; refractile anif.ctl a.. recognized by fomsing up:md down :md :use:ssing for this pro!",ny, They may appear as cre=nts or as sm:dl to brge, irregular sh'pes within the erythrocyt.. , Erythrocyte refractile structu... in blood films suined with Romanow.ky_type stains .re :dways .nif.ct" The d.fect that creat.. the refractile structure devel.o", during the drying or suining of the erythrocytes. 2, When refraclile .nifacts .'" in a pl. ne of focm that Jrulke. Ihem r..emble bl. ck structure!, Ihey can b. contu...! wilh erythrocyte indu.ions or """,,ites, 3, Refractil. arlifacts are different from erythrocyte refractile bodi.. :lS described by Sch:dm!' Erythrocyte refractile bodies are Heinz bodies seen on air-dried blood films by using. weI NMB sl. in under a cover glass, In thest prq>.ralions, Heinz bodi.. appear :lS erythrocyte refraclile bodies in erythrocytes; the bodies are dark foci in one focal plane but become ..fraclile when slightly out of focus,

142

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY H~inz

bodi..... not .. fracta~ in films suinffl with. Rom:mowsky_typ< stain

Wrij:ht,

(~.g..

Wright_Gi~msa,

or Wrij:ht_uishmon). F. Siderotic I:r.;mul•• (p. ppj«> .... (h. ... ); b.. ,." boand 3 deficiency in Japanese black cottl~,'" and with dyserythropoie.is in Englim .pringer sp.nid,." 4. Spherocyto.i. may k fal,dy detect«i if one a"eues cell, too n~.r the futher«i «ig~ of. ,meor wh~", mif.ctual di,tortion of ~rythrocytes make. erythrocytes lack central paUor. Pylmocytes may k faJ,dy ronsideral spherocytes. 5. Procuses that produce sph~rocytes may al", produce spheroid cells that are not p« the following sect, 12), Compne to the CHCM, if .vailabl., Normocytic hyperchromic an.mi:as: Typically, the MCHC is falsdy increased {see the following sect, 12}, Compne to the CHCM if it is av.ilable, Microcytic hyperchromic anemias a, Falsdy low Mev and high MCHC (CHCM) may be produced when erythro_ cyt.. are in hypoosmolal plasma,"" Erythrocytes adjust in vivo to the hypo_ osmoW.nvironment mu.ed by hypon . tremia and hypochloremia by h. vi"i: decreased cytoplasmic osmolality, When placed in • diluent prior to counting, osmo,is results in H,O leoving the erythrocyt.. and thus decreasing volume of .rythrocytes, b, If the MCHC {or CHCM} is falsdy increased for other reasono, then potenti.l mu"", of a pathologic microcytosi. mould be considered, Inc..ased MCHC or CHCM a, In theory, it is not physiologimlly possible to produce hyperchromic erythro_ cyt.. beame Hgb synthesis stops in . n erythrocyte precursor when an optimal [Hgb] is reached within its cytopl:asm, b, Most increased MCHCs n. falsdy incr....ed, and the blood "'mpl.,.' MCH value> also are falsely incrrased CHCM. are more reliable but mn .lso be falsdy increased, c.u..s of falsdy inc ..... ed MCHC, CHCM, and MCH include the fOllowi"i:: {I} P.thologic hemoglobinemia: Blood [!-1gb] is used to calculate MCHC and MCH, and it would indude Hgb from .rythrocytes and the Hgb in pia. rna, The CHCM would not be . ffected A more acrurat. MCHC amId be calculated by correcti"i: the blood [Hgb] by usi"i: • value for Hgb....., {2} Oxyglobin: Th. free Hgb &om theraJ>id "",1u'alioo • doIoc1Mo nucluic Itcid motabolism

Fig. 3.7. An "Pproocb to probJ.m...oMng .,..mi .. : Aft.,. an of glucoconicoid compounds or oth.. immunosupp=sive th~rapy. but the",py may tak~ 2 wk or longer bofo.. .vidence of respon'" (~.g .• reticulocytosi,). Some dogs =Iuire long_ t~rm th~rapy to pr~nt r~cur .. nce of an .nemia. d. Loboratory findings (I) Typieolly. thry indud~ normocytic normochromic anemia and sometimes spherocytic an~mia.

164

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY {2} Nonregtn~ra{in .n~mia {3} A Coombs' un might yidd • positin mult. (4) Mmow aoomintion ~n.J, markffi hypopluia or aplasia (.b",nct ) of the erythroid a:l.lliorag {I } Typically. thry include normocytic normochromic anemia and ",melimo. spherocytic anemia. {2} Nonregrneratin anemia, ofte" SNore {3} A Coombs' ten might yidd • positi'" mult. (4) Mmow ex;;omintion "'''",lions from erythroid hypoplas;" with an inromplm l.ft_shiftal stries (m. turation ar=t) to erythroid h)'P"rpl.. i. , oft~n with subtle but d~.a .bl~ phagocytosi, of intact erythroid pr«:llrsors at Ihe latesl stage of ordtrly d""dopment (plat~ 9G). Th~ production of oth~r cdllines i, effecti"". 3. F~LV_ induc:ffi ~rythroid hypopl .. i. a. F.LV nuy sd.aivdy damage .rythroid ""II, to QlU,. erythroid hypopla'ia or lransform a cdl into a neopla'lic cdllin•. b. PalhogII~mia resolv.d .nd th~ erythrocyt~ indices improvtd when th~ th~ .. py for copper nO"'1:e dis ...... "",...d. [m~rpreution of th~ = dar. WlI.! compliatal by ~id~nce of hq.. tic dysfunction. {4} Microcytic hypochromic anemi", do d~lop in copper-ddicient pigs. c. Folat~ or oobalamin (vitamin B,~ d~fici~ncy {I} Folate . nd cobalamin . .. requir.d for DNA synthesis, .nd thus d~ficiencies might au.., .bnormal ~rythrocyt~ d~dopm~m. Folat~ and cobal.min deficienci •• may cause a macrocytic .n~mia in people but .. rdy a.. such disord~rs found in domestic mammals. {2} Cau with aperimental folate deficiency hood m~oblastic marrow erythroid cdls but n~ith~r macrocyto1is nor an~mia." A at with a congenital coJ..la_ min defici~ncy b.d normocytic erythrocytes." {3} Giant .mnauurs with .n inherit.d malabsorption of cobalamin had a robalamin deficiency and . normocytic nonr~gene ..tiv. anemi • . M. rrow sampl.. cont:nn.d megalobl.,tic erythroid cells, .nd macrocytes and ovalocytes we .. found in blood films. Rq>ort.dly, an increasffl MCV WlI.! not p..",m btau.. of roncurrem microcytosis; an aplanation of th~ microcytosis v..as not provid.d.'" Dy.plastic ch anges in the mydoid cells indudal hYP"~ent.d n.... trophil. and giant neutrophil .. M",hylmalonic a.ciduria WlI.! also present. {4} A Bord~r coUie with inh..it.d malabsorption of cobalamin had a normo_ cytic normochromic anemi .. " {S} Cattle that d~dop a oobo.lamin deficiency &om gm.ing on cobalt-deficiem soil may d~dop a normocytic normochromic anemia." d. Pyridoxine {viumin BJ d~fici~ncy: A di=ry pyridoxine deficiency in growing kitt~m ..",h.d in .nemia, but th~ features and pathogen.. i. of the anemia w~'" not deseribtd." {2}

Wh~n

165

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

'" 5.

Endocrin~ di""rd~rs

a. Hypothyroidism {I} Sttn primarily in docs, chi, causes a mild normocytic normochromic an~m

{2}

....

P.thogtn~sis

ofch. anemi., D""""asffi [toul thyroxine] and [total triiodo_ in a d=eaIM metabolic "Ie and thus • d""r~ n~ for thyronine] 0, in "",iph.",] {;ssu... Th. decr.,.,ffi lI,""d for 0, leads to decreasal Epo production and thll'l I... ''Yduocyre production. A IIe> with liver di""""...·

1

• A ,.ll1i""ly common dioe ... 0' condition 'H omoglobinuria or hemoglobtin Be Usually at pre.enmion

NoorE • OinicaJ intr.v1K'Uw, homolysis is =ogniu< diso«kn. intw.=ubr bemoly>is rruy be occwring but not =«",ly enough to cwsr homoglobi ...mi. ot homoglobinuria. < Soon after the 0 ..... of intr>vucuW hrmol}"is. hY!"'rbilirubinrmi. and boilirubinuri • ..iU probably not be p, ... nt. Witb timr. incrrasris could contribu.. to tbe .. =s boi~rubin formation and thUll byprrbi~rubinrmi. or bi~rubinuria. HY!"'rbilirubinrmia and bi~rubi· nuri. would be mot. upectrd .. ben tI",rr is concurrent _ransrul .. hrmolysis of mf!icient du .. tion and _rrity.

2. Bu is H,O in.olubl. and i. bound wilh albumin in plasm>. so ""I}' little Bu p also ha"" a mild albuminuria. and thus Ihe bilirubin det«IN may be. Bu bound 10 albumin. 4. Bilirubinuria umally occur> be.fo.. clinical hyp Bu fix conj ugation and urinary uc",tion. Hpt, b>ptoclobin; and Hp .. htmopeUn.

175

116

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

T able 3. 12. D ifferential feature. of hematuria, hemoglobinuria, and myoglobinuria Ho P[",ma color Urine oolor

H~maturi.

H~mo~obinuri.

Mro~obinuri.

WRI" Not pink to r~d' Pink to rcd'

D,""",,,,,,,d Pink to fffl Pink to =t' Posit;""

WRI

Urine heme .. "",ion'" Positi"" RBC. in urine wimcnt Yo" No' Information to su~~r{ mUld. d . mW No No • UnLess ,b.", is :on :woci. « wi ... >«Ii""", ",,:urUn>.tion. 'The« could b. concu,,,,nt bmutu,i. bee ..... of anotb.r pathologic P'''''''' or to '""'pJ. colJ.ction. 'Infornutioa auy incJud. hiltorical or phyo;c:d ffid.nc< of muscJ. d:omoge (~.g .• "jJJ..... 0' tnwna) 0'

incre;>st of the n~rn)

(a) [n NI, ingesta! m aternal colostral alJoantibo are not known to han clinically ,ignificant naturally occurring alloantibodi.. to DEA 1.1. and other .cquired alloantibodies probably do not cau.. hemolysi •. "' {2} IMHA ..rondary to incompatible blood tr'n!fll'lion! {a} Tran,fused donor's stridium pnftingrn, type A {C uxkhil1 in hor... {I} A horse with a clostridial aoo.. had. Coombs' _positive . nemia with sphero«hinocytII acute imravascuJ., hemolytic .nemia in :lCIIte '["l:'" Mor< commonly. it is • chronic extra ..... "'ula' hemolytic anemia or .. chronic normocytic normochromic anemia. {2} Ocher finding" hemoglobin.m;" {acute}, peth.!", anisocytosis and Dl. e. Major laboratory findings (I) Chronic form: few to rare organisms in blood, mild an~mi, mild lympho_ cytosis {due to chronic .ntig~nic nimulwJ, seropo.itivity to &b,,;.. spp., and PCR positivity for &b,,;.. 'pp. (2) [n .rute or subacute forms: many piropl.,,,,, in blood, mod~rate to =er~ an~mia, retirulocytOlis, increased polychrom .. i, macrocytosis. hJ'P'rbilirubinemia, bilirubinuria, possibly h~moglobinuria, ,ometimes sphrrocytosis, and occasionally =ntrocytosi,

3/ ERYTHROCYTES

185

8. "Iki/ma spp. a. Erythrocyt~ piroplasms .'" intr.ocdlulor and highly pleomorphic, d~~nding on spa;ie! and Slag~ of par.olitemia. Many form. resembl~ CJlaUXZJIQ'" but oth~" r..~mbl. "nan b.be.ia[ piropwms. b. "Ikikr;a rqui (ba""nym, Bab"ia ~qul)''' infects horses and is ~ndemic in many tropical and subtropical ar .... Th~ infectod ho"" may han a subclinical di",,,,,, or may han pathologic SUt .. , including intr.ovascular h~molytic anemia, ict~rus. hepatom~y, and splenom~y."· c. In th~ United States {Mi1SOuri, Texas, North C.rolina, and Michigan}, bovin~ case:s of theil~riosis hav~ i>ttn caused by T. bujfiu.' ....'" Num..ou. piroplasm' w~re pr=nt in clinically ill row,; piroplasm. we", . .", in subclinicol cases. P.thogenesis of the an~mia is not esublished and may includ~ both d=eased erythrocyte production and decreased ~rythrocyt~ lif~ span (becau.. of .ith~r iDUIlunologic or oxid atin da~). Ntojor laboratory finding. ar. piroplasms in erythrocytes. macrocytosis, polychromasia, basophilic stippling, lymphocytlis, and hyperbilirubinemia and bilirubinuria. d. In other oountri.. , many lbritnu. spp.•'" ra:ogniud .. causing h~molytic .n~mi .. in canl~ and oth~r ungulates. Erythrocytic piroplasms are th~ major pathogtnic forms in T. mutant, T. orirnta!iJ. and T. "rgmti. Th~ m.jor patho. genic s~ of T. parva i, in th~ intralymphocytic schizont, wh~r..... ~rythrocytic .nd lymphocytic form. are romiderod imporunt for T. an" ufllta.''''·''' A Thn~. ria sp. wa. found in SwiM cotd~ that w~re roncut",ndy infectod with la~ &Imid .p., ANJplmmll m'''-giNJ!'. Myoplmma wm}unii, .nd A. phagoryrQphiu.m.'" •. In Spain, 21 dog. wer. "'ported to be infected with B. mi""ti.liu organisms, but .nalysis of ribo""mal RNA from organi.ms in thIN dogs indicoted that the org.nism. w~r. T. anna~. t. . The dogs wer~ anemic .nd had ""id~nce of a prot.in. losing glomerulop.thy. f. PCR testing can be used to diffe .. ntiat~ .imilar org.nisms. 9. TrypalUlwma spp. (Pl.te 8K and L) a. The.. are Hag~U atal protozoa th.t occur as fIN.living Hagdlated trypomanigot.. in blood and .. amanigot .. in J>S"udoc)",,, or macroph"l:es in oth~r tis.!ues. The p.thogenicity of th~ par..itic spa;i.. varies, and th~ host .pa;ificity is minimal. t" b. In th~ United Stat~s, T. ~i/m (b ..onym, T. amnkanum) is found in cotd~ .nd typically i. not rollSid~rod a pathogen. Th~r. are repom of finding it in Kansu, Wyoming, Oklahoma, Louisiana, Mis.iOuri, llJinoi" P~nnsylvania, and N= York. It is .1"" found in oth~r rountrie!. c. TrypanD"""a cruz; infects dog. and cou in South .nd Central Am~rico and in the south~rn Unit~d States of America. Trypomastigotes.", found in blood in the acute stagts, but mon lesiollJ involve amastigote! in nonhemic tissue! (h~art, brain, .nd lymph node), .nd h~molytic anemia is not a f",cur. of th~ disorder"" TrypanD"'''''' cruzi caus.. Chag.. di .."", in people. d. Major Mricon trypanosom .. of v"'~rinary significonce are T. crmgu!mu, T. vivax, T. brucri, and T. ,imilU. A sub.pa;ie! of T. b,uc,; caus.. African slerping sickness in people. {I} In the .cute nages of T. vivax infections in canl~, the .nimah may have an ""ute hemolytic an. mia, l.uko!",nia, .nd thrombocyto~nia. Phagocytmis of

' 0;

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY h~mic pr«ursors ~nd pJatd~ts is • promjn~nt finding in IIUrrow, :md Ihm indfa:t;", h~matopoie;j, comributes to ch~ p"lIcytopn~l1' conformational chang .. to form

hemicl"om.. (Hgb_F .... with unique binding of Fe to nitrogenous bases of g1obins) or to form a h~me-dqJl~t..d Hgb. {cl H.michrom~s or h.mMqJl.t..d Hgb mol«ul .. pr«ipitat~ .nd aggrtia). onion, {Allium 'pp.}. ph.nazopyridin•. proporol. and propyl.n~ glycol'" {cl Horses: onions. ph~nothiazin•. wilt..d or dry r..d mapl~ (Aur ,.,.b,.,.m) and red ""'pl. hybrid l~aves {gallic .cid and oth~r oxidanu).'" possibly other ""'pIe leaves. and g.rlic (Allium Ultivumj'" (d) Ruminants: Bra"k" spp. (kal •• nd rape). cop!",r. hydrogen !",roxid~ (intrav.nous). onions •• nd ryegrass (red mapl~ leaves in alpaeu) {3} Can are ""ry sUKeptible to acetaminoph.n bea.... they lack a glururonyl transferast that is usn! by most .nimals to conjugat~ .ceuminoph~n. Without th. conjugation •• ceuminoph.n is connrted to """'tin m.tabo_ lites that dqJlet~ gluu thione concentrations and th~refore d«re... prot«_ tion from oxidatin injury. {4} Pathogenesis of the anemia may inml"" multiple mechanisms'" (a) Erythrocyt.. oontaini"l: Heinz bodies are less d.formable and ar~ trapped and lysn! in the spl..,n. {b} Structural dam"i:" em=' by oxidation of membrane prot~ins or binding of Heinz body to erythrocyte m.mbrane le.ds to fr:li:il. cells that ""'Y Irs«! in cattle. P4:" and cats; how",,, .• nemia Wll.I not rq>Oned as • fe.tu .. of these form •. ''''''··''' Lead poisoning creat...n acquired porphyria becau.. lead inhibits enzym.. in the h.me synthetic pathway. An.mi. =y be pr..ent in plumbism but is not con!id"ed a hemolytic anemia caused by the porphyrin accumulation. 4. Hypo05mol .. h.molysis a. Rapid infusion of hypotonic Huid int..""nou.Jy {such as st..ile H,O} or the inge;tion of large quantiti .. of wat .. by calves {v.at" intoxication} can cause rapid intravaocular hemoly!is. b. Pathogenesis of th. anemia: Infusion of a hypotonic solution or .bsorption of l..~ quantiti .. of wat" c",at.. hypoosmol .. plasma. Rapid mo""ment of H,O into erythrocyt.. vi. o.m05i, causes .rythrocyte swdling and l,.-..i •. c. The major laboratory findings are an.mia. h.moglobinemia, .nd hemoglobinuria. the ...."iti.. of which d.pend on the ,,,,..ity of the hypoosmolar ,Urr. D. Erythrocyte fragmentation in blood c"'ating .roiwcyt... keratocyt ... or acanthocym l. Erythrocyte damage is thought to be due to trauma caused by rdatively rigid structu... (fibrin) or by rheologic forces {= T.bl. 3.10 for disorders}. but oth" f.cto .. =y be involved. 2. P.. hog.n.... of an.mia: Becau.. the .rythrocyte trauma i. a oon"'lu.na: of oth.. pathologic starr,. proa:.... that cause: the .nemia may be multifaa:ted. a. Erythrocyte trauma .ith" directly causes ly.is or creat.. poikilocyte> that have • ,hort.ned life .p.n. Acanthocyt.. =y form in the circulation became of memb",n. lipid chang.. rath" than mech.nical or rheologic for=. but th... for= may contribut. to the .ced.rated fragmentation of .canthocyt.. (budding fragmentation). b. Primary di ....... arMl'},fu. OfY'Nocy.OIIU h.. IMen

neopI~5m!I

d.oooa~

o.

confiaoed, m. .rumal is ",omiD«i ro....id.moo of tho "'".. COm""'" co""",: I>nnoconcrntnrion '" ",Ionic contr> have: produced F~ loxicosis. {2} Fe inja:tions may be administer that [nc:amre [Fe] {.... Laboratory Methods for Assessing Iron Status, socr. 1.B.4} and thus amId result in .rtonmut nBC and UlBC ,",ults. B. Incr••...! .. rum TlBC (Tabl~ 3.( 7) l. Fe ddici~ncy a. Pmpl~ with F. deficiency may Ita"" an incr"""! nBC b=me of the incr....d production of transf~rrin to corry available F~ ro crlls. b. Fe-ddicient dogs rypico.lly do not have increasod nBc.'

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

'0;

Table 3.17. Di..,rdc" and condition. thai cau"" increased TIBC inc,",asM apotr.mfcrrin production

F" deficiency: sp«i .. vari.obl. Other or unknown m.dunisms Young animals (fO. ls)

Table 3. 18. Di.."dcn and condition. thai au "" decreased TIBC D~.. ~

apotr.mfcrrin production • inHammalion Hepatic insufficiency lnn"asal transferrin lou (protein.lo,ing nephropathies, potentially other protein_Iming sUtc.)

• A ,.t1tivpl .. ia: histiocytic ... rroma (malignant hiniocyto,i, ) Shift of ferritin from tissue to plasma Liver di ..... Hemoly.i. herci", in horses • A "1";,,,,ly oommon di..... or condition

208

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

2 Inn,,=t cool during tnmpon. EIythrocytes are washal al I.... ,{ Ih,tt times with salin. or phosphate_buff.rM saliM prior to • dilute .rythrocyu su.p,;:;0

. ~

";~ ·~rJ;;;-

o . --J.o-";:;

::o..!.-;. .s~

~

3

E.

] ! ~ i l j I }' ,f~ !d I' ,j' , I , 1 ,1 "" I l"ii .. t , . ,~ j , , I 1 J, .ti~, , 1 , ••~..,'f l * , rI ~, f f J!,!j ,,~, ~ ~~. ; . ilt ~ , ' ~., ~I l .1~5 I j , ! ! netdm I"'r lOOOx field. 7. Oth.. methods may k U.ffl to estimore [platdet]: a. Som. I""'pl. advocate .numeration of platd",. in 10 thick and thin .reas of the film and us1W pbttpt]Wphilum, &bnl4 amu, &bniA pb»"I, bovine viral diarrhea virus, c:mi ne di.um!"', viru .. coni"" parvovirus. CytAUXZOt11I fty.. EhrlifhiA spp.. equine infccliow anemia virus, feline leukemia virus. fdine immunodeficiency viru •• HiJNpt.u",., cAp,"IANml, LriJhmllniA spp., L~purpiM >pp., 7Mi!nw spp, Endoroumia "Nn>plasia: carcinomas, hmungin=ma and. olh~ .. rromas. lymphoma, l. ukemias Drugs Hypophosphatemia wociattd with hyperalimcnration Anaphy\axis " A rclui.-dy o:>mrnon diooue Of condition Nooe: Usa of >peciIic disotdo .. ot condilio .... . te no< complete bu< ale peet. II.F. I} und .. idiopathic conditions until bemr characteriud. 3. Acquir..d .m~gahl}"O1 have bttn associ atal with bone marrow hypoplasia and bicytopeni. or p:mcytopen", in dogs :md prob.obly in hors .. {only phenylbuu7.0ne}, .,....... {3} Trim...:hoprim_mlfadiaz.ine and trim.rhoprim_sulfonamide ha"" bttn assoti""mia and/or

~ndotonmi.

:lSSOCiatffi with

=~

..

~nt~ritis.

d. Production failu .. IlliIy rontribut~ to thrombocytoptni"nia has oon reportal in dogs. but the

{I}

[n

patho~n • ..,'

have not oon establishal. III h. Systemic immuIIffl va,ied ddinitiom of thrombocytopt_ ni. and nl>tomeg:dy inducffl by n""plastic infiltration {e.g., hemangiosarcom.} or ,econd..ry organ conges_ tion may be associat«i with plaldel Kquestration. 4. Drugs: Ai; :dr....dy nOl«i (Thrombocyto~nia, ...as. II.CA. D.2.c, IDd D.3.b), the thrombocyto~nia """",iat«i with drugs may be :uelacking reg.rding the prrvalenc. of thrombotic or hemorrhagic tenden_ ci.. in .nimal, with clonal thrombocytosi •. 2. OIh" chronic mydoprolifemi"" di...,.,." polycythemia priJrulry erythrocyto.is. and chronic mydoid leuumi. 3. AmI< mtiofll.

PU-TELET VOLUME I.

[ntupretation of MPV ... Iu.. is limited by inaccunci.. and inronsisunci.. of routin~ MPV nteasurem~nt and limited knowl~ of f.cton influencing platdet ,ize,""" e.~ially in dontestic s~i ... A. Valu .. should b., interpreted rdati"" to rd'",enet intervals tg~ illo"", may br r~lati"" and not truly indicative of incr.. =' platd" production. 2. How"",,. ,,"~II with ages may br iner",,=' in ~~ .. thrombocytoptnw without inc",.,.. in reticulat~d platd", concentrations beau.. ther~ may .imply br too f~ platdets for ..... n a high reticulat"! platelet pt=nt>g~ to yidd an illc.....w micul at.-d [platdet].'"'a. Reticulat"! platdet roncentration. m.y al50 br ,uppr~=d by th~ mark.-dly reduced platelet Ii£. SpallS in.."... thrombocytoptnw. Th~ rdativdy few platd",. must br collsum.-d at an .ccd~rat.-d rat~ to maintain normal vascular intq:rity. "~ll

4/ PLATELETS

249

b. Also. th~ pathologic proct:S! consuming or d.. troying pl.cdeu rruoy target young and old platdeu alih. D. Th. clinical utility of «ticul.ta! platdet ...... m~nt in dommic rruommals is uncl~ar and :!W.its fimh~r nudy in a vari~ty of disord.rs. TESTS FOR IMMUNE_MEDIATED THROMBOCYTOPENIA (IMn I.

A ... riel)' of speci..tiz iD • doc and a'. J Am. v.. Mod h - 210, 175.J.- 1756. 67. w"""" ADJ, Wo, t=kity in """ """,. c...;", (', ... 6047- 5 I. 69. Wd.. DJ. KIa.,n .. Js, 1m. Dn.t:;--.datod apI .. tic "",,,,ia in ""'", Eirb< "'"'" (1984--1989) . J Am. v" Mod h - 1~472-475 . 70. MeE...... NA. 19"92. P__ ",pti... "imrtbopdm-.u.lpham ....... "'t. . ""';"od tIo.om~ and.......,;. io . do" J Small Anim Pract jJ'Zl- 29. 71 . Wd.. DJ. Ad ..... LG. 1987. Aplaotk....",,; . ...od.ted..ith trim,tIoopdm-adfadinin, and f251.

=-

00'

254

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

Ill . Wdkn"", M/, .'*wn.. w. s..i.n S, H .. kin K. Md"k.,d, J. Koun AA. 2001 . Ph,d .. .;"" platdrt ... f.cgen International normaliznl ratio International Sm,itivity I nda Inxti~ coagubtion faclors one through thi"~n; terminal "a' s" • V :ISOron>triction redu"",,, blood los~ :and actin",d ..,dotb.lial ",,[Js ""press both produombotic functions to limit b~ng md :ontithrombotic functiom to ~mit dotting. • Pt.",lett adhere to apo...d mb.ndotb.lium, 'I',.. d to patch the tions, Hct, .nd vWF: Ag values ar~ WRI. {.} Her.d.irary thrombol""hias an:: unrommon. Additional reading is avaiJabk' {b} Ac:quiral thrombopathia occurs ooncurrently with di .... ses or oonditions that are usually diagnosed by oth~r findings. Th~ thrombopathia may be. mbclinic.J or it m"y comribute obviously to morbidity. c. vWD: BMBT con be. used as. KINning ust for vWD in brtt di'cylglycuo] gU"r:lctin p!'tdm as may occur with inf=ions {~.g., fc:lin~ inf=ioUJ J>"ritonitis or heartworm di",ase} , malignanci~" th~ nephrotic syndrom~, .nd oth.. dioord~f1.''''''' A sll'lJ>"Ctffi sJ>"Cific thrombopathia m.y b.: d~monstr:lbl. by sJ>"Cific [tion and « Th. finding of vWF: Ag v:du .. that w"". WRl for hypothyroid doc' I>tocytes, meg:obryocyus, lymphocytes, and v:ascular ,mooth mu..d~ crlJ.. 71 It h.. a half_lift of about 0.5- 1.5 d and is consumal by Arc during co~lation. (2) Factor V][[ may bt producrd in muhipl~ cdl typt" but h~patocyt .. apprar to bt most imporunt. (a) It i, sex linkal. It. g.ne i, on the X rnromooome." (b) It circulatrs in a nonroval~nt complex with vWF but i, distinct from

,WF. (c) Th. half_lif~ of human factor Villi, .bout 0.5 d, but it is Ie .. in the abs.ncr of vWF, its carrier prot.in. (d) It i, consumal by APC during coagulation. (.) It i, a "",itive acute-ph ... protein, iner...ing in pi"""" with eRrci.. and inflammation."''' (3) Factors V .nd VIII ..., ronsumal during clotting and at. not prestnt in .. rum. d. EDTA, oxal.t~, and citrate function:as in vitro anticoagulanu by binding fCa""' and pr...",nting it from interacting with coagulation proteins. In vim, ther. i, alwaY" .nough fCa""' for roagulation "".n with hypocalcrmia. F. PhY"iologic inhibitors of coagulation hdp pr""~nt acessi"" co~lation. Deficiencies of these anticoagulanu are associ.tal with thrombotmbolic di ...... Som~ of th~ inhibiton con bt m~alUrai

Fig. So2. ~ti~~"

• Common path..-.y: This is th. COJIUDOn rontinu .. ion of the TF and mrfioco-indu=! path......}". beginning with > by this pathway b.au"", thrombin bound to thrombomodulin cannot d •• "" fibrinogen. and th. romplex is int>tocytes. It also circulates in pJ.tdm and in pl.!ffiO, mostly bound to lipopro"ins. In the pr=nce of ft:.", TFPI inhibit. TF_Vlh by forming •• ta bl. quater_ nary complex: TF_VIl ..... f. ctor Xa- TFPI." Thi. inhibits furth .. g.n ... tion of f:>tic.Uy. AT activity i, mo.rloodly ~nItanood in rhr preontrolled coagula.ion an prnfunnationol dtangn in AT th ... nalW i, to bind to and inbibi. f""to< Xx, bu. ".,. .brombin. • o..c.eued pLum. AT activity and _ntrotion O«W" via ...... ru"'f";"" "'''''0 intraYuculu coagubrion .. inctaOed 0' af... injecOon of."ogmow hepa.rin. Deanoed COllcaluaOono may aIaoOCCW" from dea.-.t It.epWc production at from ""CUI;"'" lou d ... to poott. mlum. rrquir":! fot ~nticoagulating a volum~ of blood with a ginn Hct:>55 %: C = 0.002 X {IOO - Hct} X V C: cicr.t. mlum. (mL) Hct: blood h~matocrit (%) V: coll= ..:! blood mlum. {mL}

(5 .!.)

E. Sampl~ processing and subility" l. Tim. and t~m~ratur. ~for. p""", .. ing" a. Excq>t for whole blood clotting =Y', studies of human blood indict. that whole blood .amples may ~ rdJig~rat..:! or hpt at room t~m~ratur. for up to 8-12 h (PIT a.!S>y for nonhqmini=:l pati~nu, IT a~, and coagulation f.ctor ~ruolY'.. ) or up to 24 h {PT =y} ~for. processing.""" b. Ho~r, a good g. Fibrin fo,m"ion;' th. ond point fo,udt "' ... PTr rnd ACT .-nlu"o =..,.,I"ion f.oClon in th. mrfacus (di.tollUceous) ~.nh, which acrivau. the mrf=_inducffl {intrinsic) pathway. b. The blood is mix..! by five in""",;o"" and the ru~ is inrub. tal (37°C) for 60 •. Th. IU~ is th.n ch~kal {visually while tipping it} ....'1 5 or 10 s for th. first

ddinite

~id.n""

of a clOi.

c. The tim. from contact of blood with s.ilaca>m ..,mh to the initial ddinite signs of a clot is the ACT. d. Units: ,,",,,lid, (nrarm 5 or to., d~nding on the f=iu.ney of inspffiion) 4. Interpreti"" colISid .."'tiom a. lnt.rpr..ution is similar to that for PIT (Stt Coagulotion, =1. IV), but th .. 1m has Jess diagnonic stns.itivity .nd may requi .. :> 90--95 % deficiency of a single fxtor for a proJong«i result. b. ~""r.. thrombocyto~nia « 10 X 10' pludm/J.lL) is commonly stat"'" to prolong ACT, b=ou.. of dee""as.,d phospholipid availobility. HoW and diff"ent thromboplastin 'liem I. [SI = 1.5: PT = 12.0.; n"" mean = 8.0 • {Eq. 5.}:!} {2} P.tient 2. [SI = 23: PT = 12.0.; n"" mean = 8.0, (Eq. 5.3b) {3} Patients I and 2 had the same PT (12.0.) when patient 2 was teJlM with. I... ..,nsitive thromboplastin rn1 hepatocyte:! in human poci, nu with hep.tocellular co,cinonus. 147 D. Th. Thrombotest PT, • modificolion of Ih. PT a=y cru.1 js PNKA .. mil;"", har bttn r.f.,rM to :as a PIVKA test, but i{ is not .ptcific for P1YKA and does not dir«:tly m ..am.. [P1YKAj.'''' '''

l. It is a PT WI that d",,",,cs da:.......d .ctiviti.. of cwguJ.tion f""cors II, VII, and X

from .ny em..,. Fa.ccor V .nd fibrinogtn

:or. not """,=bbi{,'" .nd cots.'-,.,· ..• (4) Esuo!:"", may rontribuu to AT ddici.ncy by causing a mild to mod.rat.

d,"",,,,,,, in AT '1mhesi,'''''''' c. AT loss

{I} Lik. albumin, AT may be [OS{ from Ih. body in aninuls with prouin_losing n.phropathy and with prot.in_Io.ing hrotic .yndrom. p.ti.ms, mouth om., f.ctors ... involv~ ' .. {3} ~r. h.morrhag. may contribut. to AT Joss. d. AT collmmption: inc,rasN h.p. tic d.""mre of AT ...,nzym. complexes {I} Loc.li=:i c=gulation or di""minata! conmmpti"" co"l:'-'lation ,um (Itt Thrombo,is, Sffi. II) may cou.., d«r~ased plas/IU AT activiti.. when hq.atic clearan"", of AT_enzyme complex.. exettds AT production.''''·''''·'''-''' {2} SqJsi. has bttn """",ina! with a prothrombotic condition and danaied AT activity.",·m {3} Hq.arin the"py (unfnctionata! and LMWH) aa:d~nt .. th~ u .. and, th,,~for~, hq.atic d~"n'" of AT.I ...ding to d«",asa/ plasma activity.'n.'n Secou,. AT i. ~uira! for h~parin', fulJ antiCO to hq.arin and may be hq.arin r..isunt.'''' 7. lnc",asa/ AT activity a. This is of unknown diagnostic utility .nd not considered a probl~m. b. Exogenom conisol oodminii:. ... D. A .. ria of spa:i:aliud t. m m.. y b. r, plasminogen {inaai"" zymogtn} binds to fibrin. 2. t_PA rel....d from slimulat"! .ndothelial cells bind, to the fibrin_plasminogtn complex:md proteolytically d •• "". plasminogO' b. Oecr....d ... nal function truly contribute to increased [FOP.] in some pati~nts with renal failure.'" c. Theoretically, d«reased MPS activity could contribut. to incr....d [FOPs]. E. Effect. of incre...d [FOPs] on other hemonatic functions and tests I. Prolongs valu .. for tests with clot .nd points {PT. PIT, IT, ACT, and Ltt_Whit~ clotting time} 2. Impairs pl.tdet function 3. M«hanisms of .nti~ation and .ntipl.tdet .ffecrs a. FOP. compete with fibrinogen for the active sit. of thrombin .nd thu. truly inhibit th. conversion of fibrinogen to fibrin.>.!'·'''' b. FOPs compete with fibrinogen for platdet_binding ,ites .nd thu! truly inhibit plotdet aggregation.""' c. FOP. associat. with fibrin monom.rs and m.. y disrupt normal polymerization.'1J.m 4. An incr ... sed concentration of FOP. promotes .n antithrombotic and proh.mor_ rhagic nat •.

29'

5/ HEMOSTASIS Ill.

Fibrin f"'l:m~nt D_dim~r A. Thalry: It an ~ UoN to asse .. inc",_d fibrinolysis auoc"'ta! with OOu, heIlliltomas .nd hemorrhage into lxxIy coviti.. suggest d~f«ts in =nd.'}' hemost>.. vWF ddiciency,

,l. ht~nt ,l. Activity

anem", Thrombocytoptnia, thromoopathi. H".dilary or acquirffi foctor ddici.ncies

D-dime", FOPs Fibrinogen'

i Conctntr:llion i Conctntr:llion ,l. Conctntration

(h YJ>OCO,,!:ulabl. .tat.) Co:ogulnion .nd fibrinolysis, d«reasffi d.aranu [ocreaK. ~"', fulminm, fonn of DIe.

function or vWF connOi be ",eluded. BMBT testing it nOt indicoted in p"tienu with mod.rat. to seve", thrombocytopenia becaus. prolongations of BMBT arc ",peeted and thus will nOt add new information, 3, Patt.rn 3: Isolated prolong.tion of th. PTT indicotes a .urfaa-induced pathw"}' defCCl, though inscJ>!itivity of th. PT =y may m.. k other abnormaliti." a, Acquirw PIT prolongations: This 1m}' be caus.d by h'p"tic disc ...., h.parin contamin.tion of the sample (',g,. inappropriate collection from. hep"riniud cath.ter). or heparin th ... py. and rardy is cau.w by vitamin K .ntagonism, 1Ur• • urfa.c!id.red, F.ctor VI I h .. th. shon.n half. life of th. vitamin K-J"",nd.nt faCto ... and thrtt of the five factors in th. combined TF .nd common pathway. a.. vitomin K d'pend.nt, Th...fo",. th.

304

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

PT may

~

:of&cc«i by vitamin K antagonism or abstn~ ~fo", th~ PIT,

~,~ialJy wh~n

a PIVKA·.. n';tin PT method is usa!. b. Inhuitffl or ooIli:enital PT prolongations (Tabl. 5.7): F.ctor VII ddiciencies are rare .nd :associatw with mild h.morr~, uma/ly in "'ponsr to surgical or nomurgical tnum ..

5. Pm.rn 5: Prolongrtrd in Devon rex cots and p,mibly found in a Labrador retri"""r}.'''''''' 6. Pm. rn 6: Prolongrd PT and PIT with hypofibrinog.n.mia and possibly prolongrd BMBT a. Acquirrd disorders: Hep>tic di"'''''' i, a consid"ation for thi, pattern {= the discussion of patt. rn 5}. Consumptive coagulation {•.g.• Die} could also b. conoid"rd. but thrombocyt0p"nia and inc".=' [FOP,] andlor [O_dim"] ." usuaUy expecrrd with Ole. b. Inh.ritrd or congenital disord.rs: A markrd decr..... in [fibrinog.n] along with prolongrd PT and PIT should prompt consid.ration of rare inh"itrd dJ"lfibrinog.nemia or afibrinog.n.mia. " Seve", hemorrhagic tend.ncies a" ex~trd. and BMBT may b. prolongrd. 7. Pmern 7: Prolongrd PT and PIT with incr•...d [FOPs]. hypofibrinogenemia. and thrombocyt0p"nia are typical of fulminant ole. what• ...,r the couse. Such a patient would app"ar very ill. likdy with .viden"" of multipl. organ durulg.. Findings with hepatic f.ilu" could b. similar. II.

Pathog.n.,is: The pathog.n.... of h.morrhagic d.f.cts in primary h.mon",i, rdat. to ,~ific .bnornuliti.. or d.fici.ncies in platd.ts. vWF. or the v. .... l w:.ll. Inherited disorders of strondary hemostasis are caus.d by various gt:netic .h"ations that r.. ult in d.er•• ...:!. ab .. nt. or .bnormal hemo,utic f.ctors. Acquirrd blttding disorders oft.n have. mo,"" compla pathog.n=s. The pathog.n.... of h.monatic .bnormaliti.. are di5Cussed for the foUowing .dected a.cquirrd blttding disorde ..: A. Hepatic di ....... '" l. liver di ...... con couse defn:" in the production and dearance of procoagulants. anticoagulants. profibrinolytics•• nd antifibrinolytics. The net result i, oft.n clini_ cally ,il.nt despite abnormalities in hemo,utic laboratory tests.

5/ HEMOSTASIS

305

2. Blttding is unconunon but =y occur ifhq>. tic f.ilur~ is 5tV~'" or asoociatffl with DI C. Oth~r J.bor.uory .-vid.n"" of hq>>tic f~ilur~ would ~ npa:1ffl in • pati~nt blttding b«:au.. of th~ h~patic failur~. 3. Pot~ntial abnormal h~mostatic test results .nd th~ir cau... a. Prolongffl PT. PIT, ACT, or IT {I} O,""",-d h~patic production of co.gulation factors b«:allSt of d,""reasffl functional hq>atic m..... (including pono.ynemic .hunt,"') {2} Abnornul production of vitamin K- {2} [nc",-d FOP production {fibrinolysi,} b«:au.. of aOJ Blttding complic;otion, in dog, and caU are mo", !Irongly associatffl with thrombocytop«:om. prolong«i (within 14 h)"" .nd hemorrhage may occur. 2. Yiumin K ddiciency (hypoviuminosis K) is rudy ddicient enough to COUM hemorrhage. a. Yiumin K i. absorbed in th. int..,in. aft.r i~tion or production by intestinal bacteria. b. Causes of clinically significont vit:mlin K deficiency have not bttn clarified in most species. but th. following mould be considered: (I ) Prolon~ anorn", or ingestion of an abnormal diet moy muse or contribute to vitamin K d.fici.ncy. In rontrast. normal diets contain ",a ss vitamin

mu,

K. ",~" (2) Gut st.rilization by antimicrobi;d, Im}' couse or contributr to vitamin K deficiency.'''''' {3} Malabwrption of vitamin K (a fat.solubl. vitamin)'"

{a} Intrahepatic or extrahepatic cholmasis (decrrased f.t digestion and absorption. :md ther.fore decreased vitamin K .bwrption) (b) Intestiruol mal absorption dis ....." (e.g .• infiltrativr bowd diM• ..,) (c) Exocrine pancreatic insuffici.ncy {drcr ......! fat digc:nion and .bsorp. tion. and th.... fo ... drcr ......! viumin K absorption} c. Dimini,h.d. but nOi absent. vit.min K moy lead to • subclinical mixture of normal cwgulation factors .nd PIVKA. Vitamin K supplementation wa. 'lSOCiatrd with a cor=tion of prolon~ PIVKA·..",itiv. PT values in cots with intestinal or h.patic dis .....".''' 3. Cause:! of abnormal h.mostatic test reswts a. Prolongc:d PT. PlT. or ACT (I ) Decre.,.d amounU of functioruol vitamin K-Jrpend.nt cwgulation f""tors participating in the surfa",. induced (factor IX). TF (factor VII). and common {f.ctors X and II} pathv..ays {2} Although PT is npected to be: prolongrd be:fore PlT. th.re may be: prolongation of PTf .lon•• PT alone. or both valu ... drpending on the optimization of the .....Y' and. perhap•• the .pecies involved.'" b. Thrombocytopenia {I} If p .....,nt. thrombocytopc:n", prob.bly .... ult. mOJily from coIIJumption .t multiple sitrs of hemorrhage. {2} Wh.n moderate or markrd. BMBT prolong.tion would be: rxpectrd • .. pecially if the patient is anemic.

Liver

,; "

.

Blood

Poorly carbai:e. ,hod:. or .igns of multipl. org.n failur., all1sffl by thromoo.mbolism or hemorrhagt. Sign, of the und..lying dise;o .. may al", ~ pr=m. 6. Consumptiv. cwgulopathy can "" rrcogniud when the typical laboratory and dinical signs .crompany ~ condition known to trigg'" the proa:s.s. Typical finding. are thrombocyto!",ni-m Without .d"'luate functional fibrinogen, fibrin clots cannot form, thus prolonging PT, PIT, ACT, and IT. B= Wdkb....d' • .Ii...... Am J Y" R.. 59,111_ 118. 58. J o k _ IB. 1m. 0. ....0,,""';0 ...bu>«. th, bindin& of p ...... "'0 Wilkb...,d facto. to =Ilauo in pi .. ",.. fro", ""nn.1 do", and doc. ,.;th ophilic rubricyte Polychromatophilic rubricyte Normochromic rubricyte Mcurubricyte

Erythroblasl system'

Normoblast ,ystem'

P~rythroblan

Pronormoblan Ba>ophilic normoblast Ba>ophilic normoblast Polychromalophilic normoblan

Basophilic procrythrobJ:.st Basophilic erythroblast Polychromatophilic erythroblast Early onhochromatic erythroblast Lote orthochromnic erythroblast

Early onhochromalic normoblm Lote orthochroJrultic normoblast

, Tho wu.J nomencu",,,, in ..... rinuy modici"" • Nomencl. nu. u..d primarily in hum. n modici""

A. Megakar}'ocyl.lincage I. M'Cd.myorylrS account for < I % of heJrullopoiClic cells. butlhey.re vcry large polyploid cells. each wilh the capability of producing many plndCl •. 2. Thrombopoielin and olher cytokines {s .. Ch apter 4} S{imut.I' Ihe formalion of mature megakar}'ocyles from megmryoblam Ihrough mdomifl),is: the nuclem divides repeatedly wilhout cytokinesis to form cells of prog.... ivdy greater ploidy {mon about 16N}. a. MrCakll'}obld"" which a.. the first microscopically rccogniI.able cells of Ihe series, are similar in ,iu 10 rubriblam, mydoblasls, and monoblasls, and havc single nudei and dcq>ly basophilic cytoplasms lhat may form bleb •. b. Promr£llMrytXJlrS develop from megakaryoblasls and ha"" what appear 10 be two or four nuclei and scanl amounU of basophilic cytoplasm Ih'l m.y form bleb, (pt.le 9A [for all plales, J« th. color ..aion of Ihi, book]). c. Megakaryocytes vary in ,iu and ploidy. A> Ihey dcvdop from promegakaryocytes, Ihey b.:comelarger, have: more nude.r lobulalion., and have: more .bundant, paler cytoplasms Ihal break up imo :mud•• te platdels. Malure forms predomi_ nat. (Plat. 9B). B. Erythrocytelineagc: (Table 6.2) I. [n VCIerinary medicin., Ih. nuclealed erythroid precursors .re usually named using. ,...bri_ prefiL The cell, wilhin Ihe .. ries.re Ih. rubriblasr, prorubricyte, basophilic rubricyte, polychromalophilic rubricyte, normochromic rubricyte, and meurubri_ cyte, allhough Ihe.. is a continuum of dcvdopmem making cell subcl""ificalion difficult at limes. MCiarubricytes gi"" ri .. 10 rCIiculocyt...nd JrullUre erythrocytes. 2. A> cdl. proliferate .nd JrullUre (... F~. 3.1 ) from Ihe firsirecogniUlble ,tage, Ihe rubriblast. they decr..... in ,iu and cytoplasmic basophilia while incr .... ,ing hemoglobin conUnt and associaled eosinophilic ,uining {plate 9C}. 3. [n human medicin., :md somelim.. in VCIerinary medicin., Ih. nuclealed erythroid precursors arc named by u.tion mempts or oor~ biol"Y .. mples a.. ~uirrd. "Dry tal"" do not indicote cru.t the nurrow i. hypocdlulor; th"Y may oo:ur with bon~ marrow hyp",,,,,llulariry in a variety of disord~ ... c. For roU!in~ microscopic naminarion •• th~ air-drird sampl.. a.. Slaintd with a stain thai is u.s.d for blood film. {a ROJrulnowsky Slain such as • Wright Slain or Diff_Quik}. A Prussian blu~ Slain Jruly ~ applird to ....... th~ .mount of ,tainable F~ in a sample. d. Proce ... ing requir~m~m. for cytoch~mical or immunocytologic procalures should ~ obtainrd from th~ rdevoom laboratory. 4. Proa'lSing cor~ biopsy samples a. Afi~r making imprims by touching or rolling th~ ror~ on a gw.. dide. the core ,ampl~ i. placed in a fixative. B5 or unk .... fixatin is pref~rabl~. but routin~ buff",td form.lin is adequate. (Note: k""p the air-drird sampl.. far a"oay from th~ finti"" kcau .. formalin fumes am sev~rdy alter th~ ,taining prop'cial Slain, can ~ tim ... ronsuming. Frequ~ndy. just :as much dinically useful information con ~ learnrd from a subjectin .....,ssm~nt of cdl population, by an np ....,nt;;uiv. of bon~ marrow tissu •. b. H~Jrultopoi~ic popul.tions {s,,", Figs. 2.1 .nd 6.1} {I} Numkr and struCtlm of megakaryocyus {a} Th~ apa;t~d numkr of Jrultu .. mq;akaryocytes in a .. mpl~ vari~. among sp«i.. and i, highly d~nd~nt on th. quality of the .. mpl~. ~ally th~ num!J.,r of bon~ marrow frngm.nts in aspirates . [n h~.hh, [h~r~ is usually a[ l~..,t on~ mq::okaryocyt~ ~r marrow fragm~nt. [f more mq::okaryocytes a.. found than a.. ap=ed, then mq;aka,yocytic hy~rpl",ia is p.."'nt. [f f. wer are p.."'nt, then m~gakaryolffl an:ock, th~re truly b. pure rffl ""H aplasia {Itt Bon~ Mmow Cla""ificotion •• =t. II.B}. b. N utritional d~fici~nci.. {I} Fe-d~fici~ncy an~mia: In th~ Fe-ddici.nt stat. roncurrent mydoid and mq;.karyocytic hypoplasia in

m". C. M/UtiW grtlnukKytir hypop/mill ("tr"nulocytmj,) is • pathologic state in which lh. numl>.r of granulocyt. (neutrophil ) precursor.; is decreasffl. but [h. erythroid .nd

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY m~'yocytic

cdl lines . "" not. Th~,~ a,~ not ~nough =inophil and luwphil pr«urson in health fo, • d«= in th ..e lines {o co"", gJ>nulocytic hypoplasia. I. s.-ver:ol inf«tion> and drug. han bttn r~po"al to co"", ",l«tive gr:mulocytic hypopl .. i. (fabl~ 6.4). How",""". ,in"" many of th~m han :also bttn associatal with hypopl .. i. of oth~, cdl lines. th~,e m.y ~ th~ app'.ran"" of sd"",i"" granulocytic hypopla.i •• but d:nnage to othor cdllin~. might not ~ det«tal in the .:nne marrow sample. In parvovirus inf«tions. the granulocytic hypopl",", could ~ amsM by damage to ""lJ. with mitotic potent",i. depletion of naltrophil pooh ba::."", of ex",,,i,,,, tilSl..l~ d~mand. or endotoxin_inducM d:nnage [0 marrow ",U,."'''' ln conin~ monocytic ~hdichiosis (Ehrlichia cani-I) . hypopl ..ia (typicolly gtn~ralizM) may ~ .. en in chronic inf«tions. wh.""as hYP'rplasia i. "",n in acur. inft.ctions. 2. Animal. with immun han bttn r~po"al to co"", ",l«tive megaka,yocytic hypopla,", (fabl~ 6.4). 2 Rare ca... of app.""nt immunde .br

distinction in animals .. is donr 10 human dusdica.ion schetnes..

'!be current bWJl.1Il WHO system indudes a puu rrythroid kuUrni:o.. 'CMMoL U cIau~ here :lS{ic proliferation origi""'ing in the bone marrow or, sometimes, th. spl..,n. Not all hemic na>pl"i. originating in the bone marrow is co,,,id.rkaryobl ... u, mono· blasts ± promonocyt... and .typical promydocyt.. ) must . crount for;> 20 % of .ll nucle;md ~lls in the bone marrow (ncluding plasma cdls, lymphocyt.., macrophage SO % of the nucleat«i cdls in the m>rrow ar~ .rythroid, th.re may ~ too ftw bl ... ts or blast equivalents to m..,t erituia for AML Diffuent crit.ria ar. uKu 10 st.,m from neoplas_ tic transformation of multipotenti:ol h.,matopoiplascidmydoproliferativt dist....,. (Table 6.5) include conditions that may havt mydodJ"Plastic and/or mydoproliferative fntures. a. Chronic my~fqm~nocytic Irulmn;Il fulfil], the crit.."- .nd occu'" in dogs. Th~ .. i. typically leukopenia .nd nonr"C"nerative .n~mi. with a hy~rcdlular bone marrow and .typical hyper..,gmented monocytoid cc:Us in blood, bon~ marrow, .nd often lymph nod... Fewer than 10 % of the nucl~atal cdl. are blasts. and the disorder hu a chronic cou",e. b. Oth~r condition. described in human pati~nt, havt not bttn recognized in .nimals: atypical chronic mydoid l.uk~mia. juvtnile myelomonocytic leuhmia, and uncl .... iliabl~ myelodJ"Plastid myeloproliferative di",a.-;e. 4. Chronic myloproliJirllnw dinllm: This group. which includes stveral ¥cific chronic clonal disorde .. of pluripotential stem cc:ll., i. charact~rizal by e~ive proliferation or .ccumul ation of differentiatal neoplastic cc:ll. that hayt few or no micro=pic or functional .bnorrruoliti.. (T.ble 6.5). Tools to detect donality .nd prove neoplasia are ~nerally unav.ilable for th= conditions in domestic .nimal •. Di.gnmi. i. olien b..ed on exclusion of oth~r conditions. but diff..ent"-tion from nonneoplastic conditions is difficult because th~ edt. a.. well diff~"'nt"-t.d {Fig. 6.2}. a. Chronic myrlogmow lruknnill (also known .. chronic granulocytic l.uk~mia or chronic mydoid lrnhmia) i. charxterized by. nentrophil"- .nd typically. leli shift. Chronic eo.inophilic leuhm"- {and po ... ibly hy~reosinophilic syndrome} .nd chronic basophilic leuhmia ar~ v.riants.

6/ BONE MARROW AND LYMPH NODE

'51

b. Polycytiumw """ . nd p,imJl'] "JfflrtKJfIIfi, must ~ diff~"'ntiata! from oth" causes of ~rythrocytosis (~ Ch.pt~r 3). c. M(gaka'Jocyu mydo,u or (umrial timmbiJcytiumw must ~ diff,,~nti.ta! from markal meg:obryocyt~ hy~rpla!;' .nd r~3Ctin thrombocytosis. d. Chronic idiopathk "'J''''fibm,is with (Ja,amrdullary h(mJlwpoi"u must ~ diff~ .. n_ ti>!a! from =ndary myelofibrosis. Proof th>l idiopathic mydofibrosi. i, a n~plastic ~ntity in domestic .nimals is cUf",ndy lacking. 5. Ma" uU dh(/U( (mdSftKJ""U): Mmocyumia Jruly ~ rrhrs, CD Ie .nd CD lie, but not CD lId." a. Plwmorphic populations of nroplanic ",ns are pr...nt in bon. marrow and 'pl..,n, lungs. Ii""" or lymph nod ... Phagocytosis may bt pr~ .. nt. b. Oth~r findings ar~ v>riabl~ and nonspaific, including anorexia, l.thargy, w~ak_ ness, and w~ight loss. 3. Th... nwignancir. must bt diff~ .. nt;"trd from {I} sy>l~mic histiocytosi., {2} nonna>plastic h~mophagocytic syndrom.. occurring in association with inf=ion. and oth~r malignanci.., (3) immun~_mffliatffl destruction of h~matopoipl"ia is d ... ifin! mon accumdy by oth.. m.,hods aft.. first ~ing id.mifin! by vis,",l imp«lion. 3. Cytoch.mical naim"''' a. Thest ar~ hdpful fur diff~remialing the lin~ago'(') of l~uk~mic reUs. b. Th~ !>.sic premi.., ~hind ,h~ usc of cytoch.mical mim i. tha, l.ukemic ",lis may ronuin ~nzym .. or compounds tha, are coounon or unique to ",nain ",J[ lin ... For a . mpk nrutrophil. and monocyt .. ronuin Jl

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u

:t

I j,l

",:>

.!l

! "i , -n - i ' < 1 ,J ~,,bl~ with th~ test prim~"', .. po.ration wiU yidd a dominant band. c. Polym~rasc: chain .. action a=ys for B_ .nd T_lymphocyt~ antigen r.aptor g~ne rrarrangc:ments a .. u",ful to hdp diff...,ntiat~ lymphoid neopl •• i. &om inflam_ matory conditions. {I} The pr... na: of gc:n~ ..ar"'ngc:m~nts supports neoplasia. B_lymphocyt. and T -lymphocyte gen. rrarrangements usually occur in na>plasms of th. resl"""liv~ cell tY]lel. {2} Th•• I=na: of a deta:talC"ne ... rranC"m~nt docs not exdud. lymphoid neoplasia. {3} Clonal rearrang.m~nts of th. TCR gc:ne have bttn d"'a:tal in dogs with Ehrlimill nmu infa:tions, .nd lymphocyt. receptor g.n~ ... r",ng.llYnts som",im.. occur in nonlymphoid leuk.mias." {4} Th.......y ",mitivity varies with the twu •• nd proponion oflymphocyt.. that a.. neoplastic, but don:dity am b. d.tn:1al when as linl. as 0.1 - 10.0 % of s;ompl. D NA i. from na>plastic cdls. Th...fo .., it em b. USplas{ic process in the bone Jrulrrow?

[I.

Complet. interp.. tation of most bon~ Jrulrrow s;omplel is only possible wh~n th... a.. CBC ..",In for the day the bone marrow WlI.! oolla:"'d.

3"

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY A. Hypl' immun~m.diated neutropenia, wh.",as the lamr =

luppom an infLo=tory

p~.

B. When marrow ""Uu[:uity u ""i~ de"ly incml!al nor cl.",1y d=astd and ~r. js an abnormal G:E {M :E} r:llio, ~ eBC provides duo:as to th. cau", of th. abnormal ratio. I. If the G: E (M :E) mio is inc",=ly (coJJ«tion, fix.tion, st;oining. .nd examination oflymph node ti ......~ from a living animal) .. e beyond the Jropc: of this tat, Procalur.. of a lymph node bioJ>ly are d .. cribed in KVeral !Ourees,· ....,.

6/ BONE MARROW AND LYMPH NODE B. M.jor

f~atu=

35'

of a lymph node biopsy

l. £ampl~ coll«tion and p=.. ing

a. Typiudly.lymph nod~ 5ampl.. a.. coJl«ud from ~nla~ p-~ pottions .r~ th~ immunoglobulins that .'" produ=:l by B_lymphocyt.. and plasma cdls, Th~ plasm. half_lif~ of .lbumin vari .. among sp«i.. and gp,.",dnnni4: Th~ [total prouin] is d~Cf~'=', and all prouin con""ntrations .'" d«r~asaI fpIlnirypoprottinimillj, [u caated .nd noncomptllsated ref"",_ tomr=nts the total quantity of suin.d protein.

316

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

,

Ab

!

N.

'"

fiLl'

I

"

I I I I

IgM IgA

•

Celuose aaolate strip (shaded areas mpr"....,t stained prot...... ) Fig. 7. 1. &h.m .. ic ,.pnsenution of SPE r.,ul", (proteinemi. patterns. 3.

Th~ pe=nt"i:~ det~rmin~ th~

v.

Immunoelectrophoresi. A. This is a method of id~ntiJYing the pr=n'" of specific proteins or protein components. It can ~ used to id~ntiry- th~ pr=n'" of immunoglobulin cl..... or sulx:l...... h....vy chains. or light maim. B. Th~ .. rum prot~ins are first .. p..>tal by dearophor~sis. Appropriate antibodi .. are addal to long trough. cut paralld to th~ dearophoretic separation. Th~ antibody and the dearophoretically "'Parat.d .. rum proteins diffu.., toward ....ch other and form precipitant arcs if th,,~ is a r....cti"" antig~n {e.g.• he. '}' chain oflgG} for the antibody.

VI.

Sia euglobulin test A. A (uglohulin is • protein that doe< not dissol"" in pur~ water. Th~ Sid fllglubulin .ttI is simply adding 1 drop of serum to demin~raliRd H,O; formation of a precipitat~ or flocculates is a pmiti"" te+, .\1g". unoonjug~1ed bil irubin, fatty:acids, Ihyroxinc. and m:my ot~r mbst:ma:. T ran.port. lipid< (esprcially lory prolCln In:octivales proteasoes, incl uding chymolf}'l"'in, :rnd Ihus i. an :rnli_inf!:tmJrullory prorcin I n:OClivaus prole...,. and Ihw i$ an anti-inlbmmal0ry pror cin Bind and mlll! pon fm. Ilemoglobin Bind$ and nampam iron; measured as total iron_binding capxity in chernial assay. Trampom lipidJ (cholesterol and lrigl)'urick): alKi caUed LDL Promot.. inH;unm~lion; memot:lClic .ubouncc Bind to specific anl;Vns; conanmll ioll5 an tOO low in htahh 10 be _n vi a routine SPE Bind. 10 . prcific anl;g..M; many different i..,typos and idiolypc:s of IgG gin a broad and umally indi.tiner gamma region POJilive :KUlc_ph_ protein: rarcl)'_n in lYWlIm:dian SC't:I via rouline SPE

• NIiv. APP. are proteins whose plasma or ",rum con""ntr>tions decr..,... bn:;,,,,,, of dec",....:! production by hepatocyt .. during inflammation. Thi. group indud.. albumin and transferrin. {2} Due to the plasma half_life of albumin in various .nimal. (e.g .. .. 8 d in dog. and .. 19 d in ho .... ) and the variable degre,,, of rwuced produnion. an infl.mmatory h}'llO"lbumin.mia may not be ...,n ulllil inflammation has !"'rsi..ed for at least sevtral daY" in dogs :md .. lean 2 wk in ho ..... The magnitude of decre.", i. typically mild {i.~ .•• deer..,... by < 30 %; ~.g.. from 3.0 gldL to 2.4 gldl} if inH.mmation is th~ only re.wn for th~ hypoalbuminemia. {3} The plasma half_liv., of transferrin ..~ not firmly mablished in dom~"ic .pro... However. decr~asN toul iron binding capacity (as • m.... mre of transferrin concentration) may not be =n until inflammation has Jl"rs.istw for at least a wtt!ands; that i•• what 'p~'f1 to bt on~ band on cdlul"", a""tat~ may bt ...,n .. two bands on "Cam... How~er. th. pl"nltn"" of . single b.nd on agaro,. dOtid.. within th~ amyloid had .mino acid sequences very similar to 'equences of human 1..-chains. 8. Amplification of variable regions of immunoglobulin ~n.. by polym~ra .. chain reaction is being u.snl to ch..""t"iu the donality ofB_lymphocyte neoplali . ... HoW.-vtr, analysis of small bio!"'y ,ampl.. from .. ""tive lymphoid ti.!U~ may yidd what appear. to be a monoclonal prolif~ration b.cau.. of donal exp.nsion within a ~rminal center or b.ca...., of random amplij]ation of ,mall amount. of DNA"·" P....,dodonality is present if .mplifiation produce. one or mo .. di,tinct bands. but the r.. ults.", not rq>roducible.

HYPOPROTEINEMIA (DECREASED [TOTAL PROTEIN] IN SERUM OR PLASMA) The di"'.... and conditiofl1 th. t au", hypoproteinemia ..elist..,j in T.bl. 7.4. I.

Ina.....d protein I"" from vascular 'I"ce A. Blood I"" (primarily atthog.nesis a. Intestinal =:mions. whim are rdatively protein rich, typically are digtned :md absorbed in the small intestine, .nd th.n tra"'poned to the portal syst.m :md lymphatic v.... ls. Wh.n generalized small intestinal murosal dis.a ..s or lymphatic diseases prohibit the absorption or transpon of the pro_ teins, the proteins.re Ion in f"""s. When the ..e. of proe.in los..! exCtt,!. the capability of the liver and lymphocyt.. to produ"" proteins, hypoproteinemia occurs. b. In some disord.rs, inHammatory au""tion and decr•• sed protein intake contribute to the hypoproteinemia. c. Intestinal blood loss beca"",,, of po.rasitism is on. form of PLE. 2. Di ...ses a. G.neralized small intestinal mucosal di"""",s: lymphoma, histoplasmosis, and lym phocytid pl •• macyt id rosinophilic .nteri tis b. Horses with acut •• nt"iti. c. Lymphatic di .... se: lymphangiect.. i. or lymphoma d. Intestinal blood loss: hookworms, whipworms, or neoplasia 3. M.jor laboratory findings a. Mild to marked hypoprotein.mia with hypoalbuminemia .nd hypoglobulin.mia (or normoglobulinemia) b. SPE results: The pattern is usually nonsdecti"" but may be .dective. c. Oth" findings may indicot. or suggen the inciting pathologic nate (e.g., HitroplMma organisms or neoplastic lymphocytes in biopsy s;omples. or mel.n. or oth" top>thy l. P>thog.nesis a. Thermal or chemical bums allow pl"'ma proteins to exude from cuUneous l.,ions at a rae. greater than th. rate of protein production. If the animal is not sttn soon aft" the injury, the dy.protein.mia will reHret a mixture of cuUneous protein loss .nd:m acute-pha .. inlLommatory respon ... " b. G.neralized au""ti"" skin disease c:m cau.. a hypoproteinemi, 'W', but the dysprotein.mi . prob. bly ",Hects • mixture of protein loss .nd :m inH. mmatory dysproteinemi .. 2. Major labomory findings a. Early: non ..lecti"" hypoprotein.mia b. Loter: nonsdecti"" hypoproteinemia masked by either an . cute or mronic inlLommatory dysproe.inemia E. Pl.",n. loss caused by pat ic errzyme activiti... dec ....."':! urea cona:mratioll. or increa"':! bile a.cid or ammonium conO::lllratiollS B. M alabwrptioll or maldigtnioll I. P.thogtll.. is: A mal . bsorpei"" or maldig.sti"" sme r.. ults in • d.fici. m imak. of b",ic body fuels (G1rbohydrat ... proui",. or lipids) to "pl. "" fuds used by m.ta_ bolic p:uhwaY" for daily energy. Ono:: d rpleted. protein G1ubolism and th. 'ISr of amino ~cids for glucolleogenesis lead co a d~ficiency in en.rgy and amino .cids for hq>atoa:llular . nd lymphocytic protein sylllh..is. When anabolism a CNds produc_ tion. hypoproteinemia occurs. 2. Disorde.. a. Malabsorption: Small illl..einal di ...... with gtlleraliud mucoul inmlvem.m may G1U", malabsorption of digened proteins. G1rbohydrates. and lipid •. b. Maldigmion: fuocrinr panc... tic irnufficir ncy (becau.. of chronic pallcreatiti, or p. ncreatic .trophy) creates deficiencies in prot........ lira", and amyl. .. and thus maldigtnion of proteillS. lipids (f.e). or carbohydmel (starches). 3. M.jor l. boratory fillding> a. Hypoprotein.mi •• hypoalbuminemia. and normoglobulinemia or hypoglobulinemi.

7/ PROTEINS

389

b. SPE r~,ults: Th~ pm~rn typically i, nonsd'""tin (Pl.t~ 12H). c. Oth~, findings d~~nd~nt on th~ primary p.thologic stat~ {~.g., d,"",,,,snl trypsin_lih immunor~activity with noc,in~ paner ... tic imuffici~ncy, or POO' xylo,", ab,o'ption with malab50rptiv~ nat~' [,..., Ch apter 15]} C. Cach~ctic stau. I. Pathog~nesis: Wh~n ch~ rat~ of prot~in cat.bolism aads prot~in production, th~ negativt prot~in naN, caUst, hypoprot~in~mi •. B.fore hypoprot~in~mia d~nlops, gluoo", and most strum prot~in ooncentration> {espl .nd muscl~ m.... 2. Di""rd~ .. •. Chronic di......,. such a, chronic inf..aion> and malignant na>pl...ia {Plat~ 12J.I} b. Ma,hd malnutrition 0' starvation 3. Major J.boratory findings a. Hypoprot~in.mia, hJ'P""lbuminemia, and no'moglobulin~mia or hypoglobulin~mia

b. SPE results: Th~ pm~rn typically i, nonstl'""tiv~. c. Oth~, findings de~ndent on the primary pathologic stat~ D. Lymphoid hypoplasia or aplasia l. B_lymphocyus produce immunoglobulin> and not othe, major plasma protein .. A mild hypoprouin~mia pountially can be, cr~.tffi by lymphoid hypopla!ia if oon""n_ trations of othe, prouim a,e WRI. 2. Exp«:tM dysprot~in~mia a. Th~ [total prouin] i, WRI to slightly d,""r.asection} did IIOt."

III.

Fal",ly inc..=tioll d.t .. mintion [ncre.sed albumin synth .. is inducffl by g1uooconicoid drugs or hormones • A rel1tively common di...... or condition Noto: If lolbuminJ ;, ~.,mined by the BeG method, the BeG dy< m.y bind to proteim other thrn :albumin rnd tbw yitions of all proteins oth" than .lbumin, hyp"globulinem;" may r~SlIlt &om th~ incr~ conctntration of on~ or mor~ diff"ent globulins, D, SPE r~mlu typically will diff"entiat~ the hYP"rprot~inemi .. ofh~moconctntration from hy~rglobulinemi .. of infl.mmation and lymphoid ntopl .. ia, but th.y IIUy not be able to diff~rentiate inflamllUtory &om lymphoid ntoplasti, hYP"rglobulinemi ..,

H't'POGLOBUU NEMIA (... the Hypoprotein~mia KCtion) L

For .nimal, oth" than ntonms, hypoglobulinem;" commonly O in domestic IIUmmal. have oon reviewM,'" B, Ess.ntiaUy any injury that product. an arut~ inflamllUtory reaction can inc...", conctntration, of the "",itive APP., Th"", injuries aln be due to infections (e,g" bact..ial, vir:d, fungal, or protozoal) or noninfectious condition! (~,g" phy.ical trauma, burns, or na:rosis), As a group of protein!, the incr~"M con IS, hyporfibrinogenemia is probably c;ou...i by dehydmion, If th~ ...tio is < 10, hyporfibrinog~nemia i. probably c;ousffl by inflammation, (2) Hor...: If th~ ratio is :> 20, hypc:rfibrinog~nemia i, probably c;ousffl by dehyd ... tion, If th~ ratio is < 15, hyporfibrinogenemia i. probably c;ousffl by inflammation, (3) If th. simpl~r calculation, (TP:Fib).... tio, is u...i, • "I " should b. add M to guiddine ",lues to b. cont fOr fib'inogmj is .... ibb&. in 1 ,.view mid•• bot """ .... ..,""'" of th. d .... Not. th" units we", ron.... "'d from "fl' to "idL' .0 they could b. mo .. _ily romp>n 400 mgldL if .. rum form. gd .. 60 min, • [lgG) .. 400 mgldl if .. rum did not gd by 60 min, {b} Excdl~nt ag=ment with th~ RID assay wh~n [IgG) < 400 mgldL and v..y good ~gr..,m~nt with th~ RID a=y wh~n [lgG) :> 800 mgldL" {2} For ""timation of bovin~ [lgG) {a} S.miqu.ntit.tive value." • [lgG) :> 600 mgldl if the .. rum form. a firm opaqu~ dot by 60 min, • [lgG) .. 400~ mgldL if the .. rum forms a ",misolid gd by 60 min, • [lgG) < 400 mgldL if the .. rum did not gel by 60 min, {b} Comment. • To det .. min~ th. [lgG) .t the deci,ion th ....hold. for FIT (eith.. :> 1000 mgldL or:> 1600 mgldL), the ",rum would n.ed to "" diluted prior to analysi', • Th~ =ult, of the glutaralddtyd. coagulation tost (Gamm._Check_Bl w~'" unreliable wh.n whole blood was used. r1 c, Th. te,t is ""I)' inal"'n,i"" and .impl~ b..cou", it jun requi ... glutaralddtyd., r.:.ction tu""., and pipettet, It does requi .. that .. rum"" harvested from blood, 3, Lota agglutination (Foakheck) for foal ",rum a, Principle: Lota ""ad. coated with anti_{.quin. IgG} .ntibodies will agglutinate in the prestn", of .quin. IgG, b, R..mlts: [t i. a semiquantitativ~ assay that I:"nerally agr.." with the RID .ssay ..sult. but i, not as good a, the glutaralddtyd~ coagulation un," c, Comments: Th. test i, mod.ratdyapen.i"" but tak"" only about 10 min to compl~te aft .. the .. rum is coll.cred, 4, Znsa, turbidil)' t""t for foal or calf .. rum a, Principle: Sulfat~, sd.crivdy precipitate cationic protein •• uch as immunoglobu_ lin.; other protein, ... n.... tral or nq:ativdy charged, At. con",ant [ZnSO,.], a

7/ PROTEINS

401 great~r

turbidity correspond. to • high~r [immunoglobulin]. Sin"" th~" is very 19A or IgM in foal or c;olf .. ra. th~ amoulll of turbidity r~Haots th~ [lgG] in a sample. b. The results can ~ .......d visually or turbidimetrically. Turbidim""ric ,.,...ssm~1Il ""quires a 'P'""trophotom""" and ,undard ",lutions to esublish a nandard litcl~

curv~.

(I) In fools. visual turbidity occurs when the [lgG] i. n~ar 400- 500 mgldL. which does not match with the curr~nt daoilion thr.. holds for FPT." (2) In calv.-.: (a) With a ZnSO, .olution of 208 mgfL, suffici~nt turbidity to obscure nrw.print occurs when [lgG] ;> 1600 mgldL." In thi. nudy, th~ ZnSO, turbidity tm provided a good estirruotr of the [IgG] but was not consid"ed to ~ .. u.~ful ., th~ Na,SO,-prmpitant t 400 mgldL " {3} Th~ p"'~n"" of Hgb from hemolY'is will falsely increase th~ measured [lgG] if turbidity is =sed by .pectrophotom""ty (.r 660 nm): Hgb_ induced inc"m~n" are about 200 mgldL a[ I % hemolysi, .nd 1300 mgldL a[ 5 % hemolysis." 5. N .,SO, precipiulll test for calf .. rum a. Principk Sulfit...daotivdy precipit.te cationic prot~ifl! lUch .s immunoglobu_ Ii",; oth~r protrins.re neutral or neg>tiv.-ly charged. Higher con"'ntra[ions of sulfites h.ve gre.,,, c;op"bility of praoipitating IgG at lower ooncelllr>tions. Sin"" th~r~ j,; v.-ty little [gA or [g.\1 in calf .. ra, the amount of turbidity rdlaots the '1ualllity ofigG in [h~ sampl~. b. Guiddin.. for the illl~rpreution of ",ul" with 14 %, 16 %, .nd 18 % N.,SO, .olutions."' {Note: Estima[ed ron"'lIlratiofl! do not match . 1500 mgldL, precipitates m ... n in 14 %, 16 %, .nd 18 % solutions. {2} [f [lgG] .. 500- 1500 mgldL, praoipitat...re...,n in 16 % :md 18 % solutions. {3} If [lgG] < 500 mgldL, precipiur. is , .. n in th~ 18 % .'lOlution.

402

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY c. In ano{h~r nudy. results w,,~ compa'.d with Ih~ [lgGl from a RID :assay." {Not.: Th~ markffi variation in thest ,",suit, highlighu (h~ pot~nti:dly poor accuncy or b el< of p,a:j,;on of ..... ch >.r_~is: AIf«t«i dog> han d=~ .. rum [lgA]. f. Sd=i", IgA ddiciency in beag/." Aff,",,'M docs had d.crrasffi .. rum [lgA], but [leG] and [lgM] wm eoch WRI. g. Sd=i", IgG and 19A deficiency in W.imann.",: Afftct«i pu!'" ha", d~r.asal . becom~ more difficult .nd unctnain when th ..e typical associations are not found; for example, possible monoclonal gammopathy in an animal with. chronic infection. Th~n, mo .. definiti"" ch aracteriI.ation of the inununoglobulim mayestabli,h th~ pathogenesis for th. gammopathy.

=y'

7/ PROTEINS

""

COLLOIDAL OSMOTIC PRESSURE (COP) (O NCOTIC PRESSURE) I.

PhpioloCic proce=. and con~pts A. COP i, al"" calla! oncotic pressu",; th~ prdix OruYl· com~' &om th~ Grttk for "bulk" or "swdling," which, in thi, context, ",f~", to 'po.a-. cont:aining rolloidal partid.. that .wtll with fluid. A mor~ common contat refu. to nnlpl ..Jns; th>l i" oncolocy· B. Hydraulic pressure g,..dients and COP g,..dients for~ the movem~nt of protein.poor fluid, out of and into copillari.. as described in Surling'.law (Fig. 7.3 and Eq. 7.2). In health, th= gndients a", imporunt for th~ maintenan~ of blood volum~. In ""'em•• touo, transudative, and audati"" disorders, alteratiom in the gradient, cous< pl,mill. H,O to move into intemitial.p:oces (..., Chapt~r 19).

Pressure gndient = tic p.am.. t-:a .... the pwm. [tlISma pmleln.) Plasma osmolamy > Inter;;titial fluid osmolality Fig. 7.4. Concq>t\UJ 'oprnarri.r, its ncgativ. charg' a1K1 imped.. transit. Albumin i. not apectnl in th. urin. of cats, hor .... or con!.. A small IDlount IIUy be found in th. urin. of app ... ntly h.a1thy dog,. Thi. albuminuria IIUy represent a subclinical disease or a 'peci" variation. B. GFR l. GFR is th. ralC fluid moves from pi"""" to glom.rular filtrate and i, mrasurffl by determining the rat. a substane. i. cl'~rffl &om pla,ma. 2. GFR d'rends primarily on th. rate of RPF . nd vari.. proportionatdy with RPF. RPF dep of ..nal tubule. are reflretal by th~ rat~ of urinary acretion of a pWIIU mbstance comparal to th~ rat. of inulin auetion. A. [f acretion of a solute i. greater than acretion of inulin, there i• • n", solute srcr.,ion by tubules. Ren. 1 tubular KC"'tion involves proces.ses by which solut~. from pl.. ma, interstitia! fluid. or tubular cell. are tran>f~r..d to tubular fluid. B. [f acrffion of. solute i. I. .. tru.n acr.,ion of inulin, th~", is a nff solute resorption by tubules or th. ,ub",ance does not frffiy pa.. through th. filtration barri...

[V.

Function> of tubules renaining to major solutes' (Fig. 8.2) A. N. + J. About 7S % of filtrat. N. + is resorbed in the proxima! tubules down a oo"""ntration gradient establi.hal by th~ N. +.K'".ATP ... pump (basolateral mnnbrane) .nd a Na+. H"" antiporter. Na+ resorption i•• nhanced by an d«trical gr;od~nt tion gradient cre.tM by Na+ .nd H,O resorption .nd through a format~.Cl- exchan~r.

2. Cl- i, r=>rbnl vi •• Na+. K+.2CI- cotranspomr in the thick ..""'nding limb of the loop ofH ~nle. 3. Cl- is p..... ivdy resorbnl in the disc.t n~phron by an dectroch~miao.l gradi~nt ~nablishM by Na+ movrm~nt (through . ldos{ '''''

: _ _ Ie.g.,

0-

ON

urea

J

.",

_

(+) ..

tubule

"'"""

> '''''

)l)l).eool_~

"' _ _ 'PKIO _

.... i . . . .

_

.

11.1.;0. pbyoioIogiC P' : " , .. of _01 rubulos dw ~ to ooIu... and H,Q. n.. ..lute _ .miom.,., pe[ivating .n adenylate crd,..., p.thw"}" ill the conical chick asullding limb of the loop of Honle, the disc.! tubule, .nd the conna:ting stgmem be{y,,",,11 Ih. dinal tubule alld Ih. colla:ting duel>. 3. Viumill D promot.. 0..'+ resorption in Ih. dinal lIq.hron by inducing production of a colcium_binding protein. Cakit,iol (1 ,2S_DHCq formation in the proxim:d ",nal tubul .. i. stimulot.d by incr~ PTH .ctivity and hypopho.ph . temia. 4. Thi+ in the disul nephron. G. PO. I. About 85- 90 % of filt"te PO, is r...orkl cdb of the roll"'t. ing tubules, r~",lting in activation of a prot.in kin. ", th.r phosphoryl.r.. aqu. porin 2 .nd .ruobles it to be tnmpona! from v.. icl~. to th~ .pical membrane. Lack of ADH triggen ~ndocytosi, of aquaporin and its return to cytoplasmic vesid ... Water mon o into cells through th. po« at th. c;.,nter of the prouin,. Water '>Capes to the inr.rstitium through por.. formal by "'Iuaporin 3 in th~ basol.r~ral membr:l.nes of the prin 1,050; osmolality:> 1500 mmoUkiI, c, Ascending limb of the loop of Henle (the diluting segment of the nephron) {I} The a=nding limb is rdatively impermrable to H,O but activdy pumps el- and Na+ {al.o K+, fC.'+, .nd fMg'"'l from the tubular Huid to the interstitial Huid, Thus, tubular Huid 10..,. solute and the interstitial Huid becomes more hypenonic, Fluid l",ving the a=nding limb for the dinal tubule is dilute (USG .. < 1,007; osmolality < 200 mmollkg), {2} A functional """"nding limb is n=ry to mainuin a hy~rtonic interstitial Huid in the medullary rrgion '" that H,O may be p""';vdy resorbed in the descending limb of the loop of Henle .nd in collecting tubules, {3} The a=nding limb .nd the closely :lSSO of the ooumercur",m system that maint.in a hy~rosmolar medull.ry interstitial Huid,

,h.

c.

."

8/ URINARY SYSTEM d. Dinal tubul~ (distal convolut~d

tubul~)

{I} Th~ disul tubul~ has minimol H2 0 ptrm ... bility, and thus nry little H 2 0 is resorbtd in this sq:ment, {2} The r~50rption of N.+ and Cl- in this .rgment low~" the tubular fluid osmolality, ~ , Coll«ting tubules {I} The coll«ting tubules of the disul nq>hron contain the concentrating process.. of th~ nephron, {2} ADH controls ptrm ... bility of th~ epithdium to H2 0, H,0 is r~50rbtd in th~ pr=nce of ADH if there is .n osmolar gradient becwttn th~ tubular fluid and mfflullory intef5{itial fluid, An osmolar gradient is cre~t.d by high roncent .. tions of urea, Na+, ~nd Cl- in th~ intemitial fluid thot ~r~ pro_ duced .nd mointain.d by segm~ntal functions of th~ nephron, {3} The H 2 0 rnannds through the epithdial cdls are c.. >I.d by m~mbrane_ :u5OCit.d protoins call.d aqu"p"rilf', When ADH binds to th~ renal ~pithdial cdl basolateral memb .. nes, it activ,u .. a cyclic adenosine mono_ phosphate (cAMP}-d.".,nd~nt 5«Ondary mess~nger .ysum by which aqu aporino are transported to th~ apiml membranes, .nd thus membranes ba::ome ptrm ... ble to H 2 0, ADH :dso 'P!""''' to inc ...... production of aqu'porino,' 3, For kidneys to concentrate the ultrafihrat~ , th~ following are necessary. a, ADH mmt bt p.... nt, Stimuli for ADH =",ion include hyptrosmolality, d«reastd cardiovascular pressures as =n with hypovol~mia, and, to a I=r d~grtt, increas.d [angiotensin], b, Epithdial cells of th~ dinal nq>hron must bt ... ""nsin to ADH, c, The.. must bt • con""'ntration gr.di~nt; th . t is, the o.mol:diry of the int..,;titi:d fluid of th~ renal medulla must bt gr ... ter than the mmol:diry of the fluid in the tubules, 4, For kidneys to dilut~ th~ uhrafiltrate, the following are n=ry. a, Na+ .nd ct must bt .ctin ly transport.d from th~ tubular fluid to th~ interstitial fluid by q>ithdial cell, of th~ ascending limb of th~ loop of Henl~, This prace.. r"'luites ddivrry of Na+ and Cl- to th~ loop of H~nle, b, Very little to no H 2 0 is remov.d from th~ tubular fluid by the distal n~phron, D, The osmolality changes that occur in a nq>hron during th~ formation of urin~ a.. illunmed in Fig, 8,3, CHRONIC RENAL INSUFFICIENCY OR FAILURE L

Wh>l is chronic .. n:d imufficiency or f. ilure? A, M.ny chronic diseases moy dam"l:e kidneY' suffici~ntly so that functional .. nal tissu~ i. iruod"'luate to mointain h... hh, Th~n, the anim.1 ent~" the pathophy.iologic state of chronic renal insuffici~ ncy or failur~ , B, Ther~ a.. no uni"""ally a.c:cept.d definitions or criteria for .taging impairrd r~nal function, On~ .yn~m seems to oorrdate with dinical finding> seen in many domestic mommal,," I, Diminished .. n. 1 .."'tv2400

-

, ."

r

--maximal coooonlration

;. J--""' ~----l---------~--"':-:---------!!>~"::"""'" --Plasma

PCT

Collecting Tubulall

Glomerulus

Fig. 8.). OsmobJjty ch1Dll"' in > h../tby momrrul'. nophron. (D.t:lils of tho movomont of ",Jut< and H,O in nepluons "'" dosaib. LOBO).

2. Chronic r~nal insufficiency: Th~ GFR i, approximatdy 2Q.-50 % of normal. Azot~mia and an~mi. ' Pl'='. Polyuria occun btall5< of da:r~ ron""",rating .bility. 3. Chronic rtnal failur~: Th~ GFR i. < 20--25 % of normal. Aro .. m;" and impair~ rono::ntr.ting ability (thu. polyuria) .'" prestnt. The kidnoy. connot regul ... atracdlular Huid ""lume or dectrolyt~ bal.no::. and thus «i~ma. hypocal 1.(40) with an estimatw 83 % loss in ",n. l function! II.

Why do animals 10.., r~nal conctntrating ability in chronic ",nal failur~? A. Mor~ solut~ than usual is pr=ntM to th~ r~maining functional nq>hrons, and th~ high solur~ ront~nt within th~ tubules rontribut~. to 501ut~ diur~.«I. Notl. «n>l. and postr.".] disorden mayocrur independently or m:oy oerur in combinations.

8/ URINARY SYSTEM acute "n. 1 f. ilu". Animals with "nal failure m. y .Iso b. hypovolemic. Accordingly. at the time of p".. ntation. an .nimal·s awtem", may b. the product of both renal and extra"nal factors. B. Th, major J.bomory crit"ion for diff"enti. ting awumi:u involv." the USG .... Ho"..""r. the diagnonic",n must ronsid" the "nal .nd atra"nal f. ctors that moy infJuenct an .nimo]', .bility to oon 1.040 (in alU). or :> 1.025 {in cotd•• nd horses} ba::."", the kidn')" ..., b.ing stimu!'talto oo"",,rv. H,O. 2. If the USG ... is b.low th= values in awtemic animals and th". is no ",id.nrption of H,O crzotem; .. occur with ..nal or postrenal 37.0um;"" wh.reas Ih. ~.{.n

.. rum UN:Cn r>tK>s ~r~ found in pr~rena! >7.Ot~mi ... Ho~r, r~nal awtem;" cannot b. co",ist~mly diff,,~miata! from extr>r~""l awt.mw by me;om of th. serum UN :Crt r>tio b.cause of the onrlapping range". 2 Con""mrations of UN and Cn in ..,rum should b. regardal a. crud. indi"". of renal function b.cau.., both lock di~no,tic 5tnsitivity and spa;ificily for renal dysfunction emstd by renal di..,ast. CREATIN[NE {Cn} CLEARANCE RATE

I.

Crt rk"raru:r ralr, which i. th~ rate Cn is d~ared from plasma by th. kidn~., i. a good e'timate of GFR in domestic animals but i. not aJuivalem 10 GFR. A d=rastd Cn clrann"" rale (if a valid result) indicote:s the animal has a d= ...a! GFR. However , th. COU5t of the d=ea..M GFR can b. prerenal, renal, or po'lrena!.

[I.

Crl

cle~nn""

rate formuJ. (Eq. 8. I)

.. cI.... rana: "te = [Crt l, xvo) C r.... WHn. ume. . ... lJme ... bw

[Crtl [Crt]. = Crt con""mration in coUecta! urine during a timal coll=ion pc:riod [Crt], = Cn con""mmion in serum from a blood sample collecta! during the tima! urine collection period volum~ = urine volume (in ml) collectal during a tima! collection period time = l.ngth of tim. (in min) during th. urine collection period bw = body weight (in kg) of animal unit, = mUminlkg = ml of plo,ma thai were de.red of creatinine/min/kg

(8.1. )

8/ URINARY SYSTEM

'"

Ill.

Endogenom Cn d~~ranc;., m~ A. Indication, l. To ousess GFR in noruo7.0t~mic, non..dehydrated animal, that are .usp«:t~d of having ,""ruol di",ast. mu:dly ~l1St thq :U~ polyuric 2. To obuin a mo", objective """ssm~nt of th. dis may allow in vitro crystal formation, especially if tho .. mpl. is Sloral at 4 'c."

[I.

Procalur.. for. routine urinalysis have: been descriW .......

8/ URINARY SYSTEM

.41

Ill.

Common compon~ms of mon routin~ urinalyses A. Physical ~umination: color. darity•• nd USG ... B. Ch~mical namination by r~agtm mip methods l. Common """y" pH. protein. gluoosge. but they localiz.ing challenged to do. a. Maximal urine dilution in dom.stic IlUmrnah as .......d by USG.,.: n... 1.001 b. Maximal urine concentration •• ~ by USG.,.: cats:;> 1.080. dog. n~.r 1.060. and ho=. and catrl~ n.... r 1.050 c. Usual USG .... ""lues wh.n H,O intal.:~ i, adeq""t~ .nd hydration status is normal: dogs (1.01 5- 1.(45). caU (I .035-1.065). hor"" (1.020-1.050). and cattl~ (l.015-1.(45). How~wr. th. USG .... may be lo~r or higher in . nimals with normal ",nal function. D. Im~rpreution of USG .... ""lues I. A USG ... is usually neffied for th~ ....... m.m of r~nal rona:mrating .bility wh~n animah .re awt~mic. polyuric. oliguric. or anuric. Because of th~ many v.ri abl~ that chang. urine ",lut. cona:ntr. tions. it i, difficult to formulate firm guidelines for th~ im~rpreution ofUSG .... in all cas ... c.

Wh~n im~rpre{ing ~ith~r

.47

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

T able 8.8. Major p"chogcnic mechani.m. of polyuria Solut~

Chronic ""nal f.ilur~ Acut~ ""nal failut. Postolmructivt diuresis' Di.!>'tes mdlitw Hyp Canin~ pyometra Hypokal~mi> Hypoodr~noconicism

+. + +

diuresis

.J.. Tubular respon ..

.J.. Malullary

toADH

tonicit!

. ADH

+ +. +.

+

-'

-'

+ + +

• • -'

+' +

1<

LiV 1,030 in an oliguric dog, ;> 1,040 in .n oliguric cat, and;> 1,025 in oliguric horses or cow>

Table 8.9. Guidelines for inlerpretation of USG...- values in a dog Co..., infOrmation USG .." Im~rpmalion Nothing known

1.001-1.060

Dehrdr:al~

> 1.030 1.014- 1.030

1.007-1.013

< 1.007

Polyuria

;. 1.020

1.007-1.013

< 1.007

Oliguria

Glucoluria

;. 1.030 1.014-1.030 1.007-1.013 > 1.020

1.007-1.020

Hyposufremia and hypochloremia

> 1.0 20

1.007- 1.013

Could be found ;n a clinicaUy heahhy or sick dog ReAeclJ rem! anemplJ 10 conserve H,O appropriately Sugg.m impai.~ .em! cooormraling ability and pouibly rem! F..ilun:; could be 5ftf\ wilh g1uooouria. hypon:mmtialhypochlon:mia. parlial n:naI diabeles imipidus disorders. h)"p'»d rtllocon:icism Sirongly indicates defKlive renal oonuntt:ning abili()~ if arolrmic. then ",nal insufficiency or f.tilure until pro""n OIherwi.., Strongly indicates defKlive ",nal oonuntr.ning .bility bm nOt d~ 10 renal f. ilure. as kidneys ha"" ability to dilule ullrafi!rr:ate; consider cetltr21 or ",nal diabetes insipidus disorders Reflect> n:naI altemp" to conserve H,O and dm, not in ren:ol imuflicitncylfailun:; could"" £rrn .... i.h g1Ua.:4Uria, hyponatrmtialhypochlon:mia. partial cmtr21 or ",nal diabetes iruipidus disorders Strongly indicates d.r.ai"" ",nal oonuntrning ability; if u.otrmic. then ",nal insufficiency or f.tilure until pro""n OIhrrwi.., Strongly indicates dd"K1i"" ",nal concen!t:uing .bility bin nOI d~ 10 rena! F..ilure. as kidneys h.;ave ability to dilule ultrafiitrate; consider cetltral or ",na! diabetes imipidus disorders Reflect> n:naI aI.cmpts to conserve H,O :approprialdy Uncommon: suspect oCUle ",nal f.iJu", Typiol fOr oliguric renaJ F..ilure; acute Of chronic Reflect> n:naI concentrati ng ability but rnay be pmialJy impair~ by ..,Iute diun-sis or d«rcasft! m~ulJa.y hypertonicity (mr~d from ultr:lfiitmr {e,g" ",me albumin .nd mull .. globulins} .'" not and thu, a.. rxcreta! in thr urinr, Inc",asrd num~rs of protein band, rrpresrming proteim with a mol«uiar mass Ie" chan that of . Ibumin a.. rxpretal with SOS·PAGE of urine from do!}! with tubular proroinuri., ..... b, Tubul .. proteinuria.< arr usually a"ociatal with acure rrnal di, ...... {toxicoses .nd hypoxia} but can ~ rongenital, They do not produ~ hypoalbuminrmia. 4, Hemorrhagic or inHammatory protrinuria (aho callal ..cretory or post.. n. 1 proteinuria, but hrmorrhagtionl . 2. With a protein_losing nephropathy, the glomerular · .i~.." krom. more porous, and larger protein> or charged proteins that usually are ..".lla! ~nter the remol fihrat~ via glomeruli. [f the ability to ..,orb prouins is nceeded, th.n a proteinuria will be pr~sent. Th. continu'! 10.. of protein willlrad to hypoalbuminemia. As long as the numkr of functional glom.ruli is .dequatr, ure•• nd Crt will k adequately ",mova! from blood .nd notemia will not develop. 3. [f the glomerular dise= destroy. more nephrons, then renal failure ocru ... The f...... "'maining functiomol glom~ruli connot ",mon urea .nd Cn fan enough from the blood, so .zotemia develops. Proteinuria continues kcouse the "'maining function'! glomeruli .'" !",rmeable to proteins. Th~ """,rity of hypoalbuminemia iner..... because of continued albumin loss, but d.fective ncretion of H,O (associated with N .+ .nd H,0 rff~ntion) m.y contribute to hypo.!buminemia. F. Benc~ Jon .. prot~inuria (immunoglobulin light..ffiain proteinuria) I. Analysis of urin~ for Ben", Jon .. proteins is not part of. routine urinalysis. [t may k indicated to clarifY the type of proteinuria or to investigate a possible lymphopro_ lif.ratin disease. 2 Bmcr jon" protr;ns ar~ light chains (~ither I( or Aj of immunoglobulins that havr unique therm.! propenies: th~ precipiuu ktw«n 40'C and 60 'C, return to a solubl~ sUte at 100 'C, and then pr~cipitate again when cooled. The thermal properties of B.n", Jon .. proteins .'" due to the variable portions of the light-chain prouins." As d.scriba! by Ritzman and Danids," these prot.in> were first recog_ nized by WJliam Maclntyre in 1845. Dr. Maclntyre..,nt th~ urine .. mpl~ to Dr.

Healthy Animal

'-/--,,-;;-;,;-..-;;-,!----1 Kidney

Protein-losing nephropathy

Kidney

@@

,:::::::::::::"~,~ ~"A':>":::" "'" A 0 "~c :--;j'I' ..A,. ",",~I(d'., •• !p."/", ., • c

U

, " A" , , A

....

: u:/

•

:".,:

•

"..}J.'

..... .",.

•••• y ••.•

. .

.I> • 'c'

:7":" ii,:c

cu

•. .~ .....'u:

.....

A

,·······u Au C"c A" ,. C A "c U

.'

c

A

Fig. & 10 . Pro .. in.]"";"!t nrpbrop. thy and I'ftW foilu",. iHUiIr:l';O ... dt~ .nd ~_ hydroxybutyrat~ ar~ nonr ..orbabl~.' B. An:dytical con 200 mmollL {using 3 % H,O,} or:> 50 mmoUL (using 30 % H,O,) to produe.. mor~ than a tract ...ction. At such ronctntrationJ, th~ [acttoa=at~l would probably b. great .nough to b. d.tect~d routinely.'" 2. Acrt~st tablet m.thod {fuy.. Diagnonics} a. Principl~ It is the same .. with the =t:~nt strip method. Color chan~ is ...,i~r to detect, so it has • low.. detection limit than som...agrnt pads (about 5 mgldL in urin.) and thus may b. used to confirm tr.e.. or questionable .. actiom on r~ag.nt ""ds. b. The m.thod may b. used '" a qu:ditativt ..... y for blood, plasma, urin~, and milk. C. K.tonuria (Table 8. II I l. Krl,muriil oa:urs wh~n the mobiliLotion oflipid. i. inc",asnj ba:;ou", of. shift in .n~rgy production from cubohydrates to lipid. {~.g., in di.b.t .. mellitus, starv.tion, and hypoglye..mic disord ...}. E"Jrct ... ivt ~_oxidation of fatty acids in h.""tocytes grn~rates mo", acttyl~nzym~ A than em b. used for gluconeogen .. is .nd triglfC"rid~ .ynth.. i•. Exe..ss ~-d, with modificotions. b. The m.thod may be used .. a confirmatory test .nd al"" to test for fet"al occult blood. 3. Unfortunately, Iher. is not. widely av.ilabl.labo.. toty .....y for diff",.miating myoglobin from h.moglobin in dom.. tic mammals. Diff..emialion i. umally a.ccomplimrd by clinical drductive r,""",ning {s,"" T .bl. 3. l2}. a. A simple pr,""ipitam test using ammonium sulf. t. is oonsiderw umeliable. In theory, h.moglobin, bUI not myoglobin, pr,""ipiut.. in 80 % ammonium mlfa,. solution, wh ...... myoglobin pr,""ipitates in . 100 % ammonium sulf. t. ""lution. Howev.., d.natu",d myoglobin will pret:ipita,. in the 80 % souhion and thus be incorrectly classifiw .. hemoglobin.'" Also, a !imil.. erronellu. cbssificotion wiU "",ur if the urine pH is nOi adjustrd to 7.0--7.5." b. Immunologic methods ",quire species-specific amibodi... El,""trophomic and spectrophotometric procedure; may be .mployw. 4. Th. hem......y is more .. nsitive than the protein • ....y. Therefo"" when smaU amoum, of blood are in th. urine, the", may be marked hu"" positivity without the hemoglobin cou,ing. positive protein ",.ction. C. H.m.... positive ",xtion in urine (T.bl.. 8.11 . nd 3.l2) l. Hem.turia

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

'"

a. Erythrocyt~, ~nt~r th~ urin~ vi. h~morrh"l:~ into th~ urog~nital tract. H~mor_ ,haglive bacteria can ret!uce nitrate to nitrite. B. An:dytical concept' for the reagent strip method I. Principle: Nitriu rncts with p-arsanilic .cid to form. diawnium rompound tru.t roupl .. with N_l_naphthyl ethylenediamine to form. pink product. 2. F:d.. ly incr ... offi ",action! =y ... ult from an:dysi. of nale urine rontoining con_ taminant bact""'. 3. F:dsdy decrrastd reaction! =y occur if the", is insufficient time (< 4 h) for bacterial ret!uction of nitrates. Asrorbic acid {especially when USG i, high} Im}' produce: f:d .. ly decr ... offi "'.ction! in dog and cat urine." C. Nitrite-positiv. "'~ction l. Suggrni"" of. Gr:lm_neg>tive Mcter",l infection in the urin:ory tract 2. Detection of nitrites in urine i, • screening procet!ure for Gr:nu_negati"" Mct..i:d uriruory infectiOn!. Significant bacteriur", Im}' be pre"'nt but undetectet! with the nitrite ....y. D. Man v.terinari.ns do not find the urine nitrite test to be diagno,tically valuable btcau", it d~ not d etect .ignificant bacteriur", ron!istendy.

x.

Leukocyte este.... in the urine A. Physiologic proce.ration will ~nabl~ • mo", critical a"e"ment of the Rmiquamitativ. r~sults. Th. quamity of urin~ used may v"'}' betWttn labontori.. but is usually 5-10 ml. About twice the amount of sediment would be expected from 10 mL m..n from 5 mL. Expected findings in thi. chapter are b.... d on th~ sedimentation of 5 mL of urin •. The cont. nts of urine are not suble. so urine should be analyzed within a few hours (id.ally within I h) of rollection. During sample storage. cells .nd casts deteriorat •• crystals may di"oln or form. and Mct.ri. may di~ or proliferat • . The method of urine collection should be considered wh.n urinal)";' and especially urine sediment results ar~ imerpreted. A voided .. mple may contain cdls and Mct~ria from the genital tract. A catheterized sampl~ may conuin mo", q.ithdial cells or . rythrocytes beause of urethral traurruo. A .ra_ tions Jruly be hdpful. Con in healthy.nimals AMociated with glomerular proteinuria {especially hyaline cast.} 'Age. bur diff",.ntiation of glomerular .nd nonglomerubr hemorrhage by urine erythrocyte app"'rance h .. not oon reported in ""terinary SpecIes. 2. Iatrogenic hemorrhage a. Blood vessel. may be damaged during bladder palpo.tion, cystocentesis, or catheteri7.;Otion.

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY b. Animal, with h~mOS{"'is d~f~u or urinary muoos;ll di,,,,, .. may to iatrog~nic h~morr~. 3. w.nital mct hemorrhage (associated with ithdial ""Us}, erythrocyt~, leukocyte, fatty {lipid droplithdiaJ cdls, and dum!" of renal tubular q>ilhdium may look .imilar to lran,ilioruoi

.pithdium. 3. All cells d.uriorau in utine and thu, ,,~ best a.min.d in fwh utine. C. Clinical significmc;., of ~pithdial rell, in urin~ I. Epithd",l cdt. m"y ~ found in th~ utin~ of h~ahhy animal" ~lIy in cath~w. iz.d .ampl... 2 Mor~ tr:ln,itional qJithdial c;.,1I, m"}' slough &om inHam.d or hyp. 3. Nwpl:ostic epithd",l cdt. truly ~ detaot.d in urin~ s.dim~nt. Diff~"'nt"'tion of malignant from nonmalignant lion' of centrifugal, fmh, n~ly form.d urine truly also ~ useful. How"""r, diff~"'nt"'tion truly ~ impossible. Dyspl>Stic and proplmic (re"C1ive) cdl, ar~ rommon in utine from animal, with cynitis and rextive hypsmo ratio is proportional to th~ rat~ of urinary nn~ion of a subnance (Eq, 8.5b), Thos in th~ num~rator and d~nomi_ nator formulas "'~ ~ith 30 mg/dL are referred to as albuminuria or Dvm albumi ..uriil. It is imponant to remember that a urine [albumin] of 30 mgldL in urin~ with a USG ... of 1.010 would have :m [albumin] of 60 mgldL if the USG"" was 1.020, or 120 mg/dL if the USG ... was 1.040. 5. Som. authors sm~ that 30 mg/dL i. the decision threshold for microalbuminuria ba::..... common urinalysis m~hods do not detect protein concent.. tions < 30 mg/dL Ho~r, the Ch~mnrip p.ckag~ in",n nates that, in 90 % of urin.. t.. ted, protein concent"'tions ~ 6 mgldL producal a color ch anC". For the Muhinix system, • t",ce r..ction corresponds with an estim.red [protein] of to mg/dL When turbidity standord 5Olution. are u",d with th~ SSA t.. t, increastd turbidity am be detected wh~n [prot~in] is 5 mg/dL B. Analytical roncepl5 I. Quantitative immunologic ....y a. Th~ immunologic microalbumin .....Y' .'" .peeies .peeific ba::.u", of the .peri.. diff..ences in albumin molecul ••. Enzyme-linked immunosorbent .... y. (ElJSAs) :md nephdom~ric assay' h."" been d""doptd for c;onin~ .nd fdine urine." b. The stondord 501utions for the assays are canine or fdine albumin. For on~ ELISA, stondard solutions w..~ diluted to cr..te.n analytical "'''i:e of 1.930 ng/mL (0.19- 3.00j.lg/dl)." Urine .. mpl .. ~'" diluted (up to I ; 3200) to obtain urine .lbumin concentrations within the analytical rancr of the assay, but surn marked dilutio", c:m be a source of .nalytical error.'" 2. Semiquantitative immunologic ....Y' a. Comm~rcial""'Y'.re marketed as ImmunoDip C.nin~ and ImmunoDip Fdine; both are call~d E.R.D._HealthScrttn Urine Tests (E.R.D. is:m .bbr""iation for

482

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

"'''Y' .""

.... rly renal di..-a,.}. Thest similar to an ..say denloptd ror human urine (Irnmunodip, Diagnonic Chemieob). h. Aft.r the urine solute oonctntr:u ion has bt.on adju,eM to a .ptcific gravity n"", 1.010, the d~ict j, dip","", into the urin., and then the r.action is gnd.d

visually. A nrgatin ,...."cion is npectffi if the [albumin] jt < I mgldL. Higher oollctntration, . '" grad,"", from low posjtive to vuy high positive b ..al on color chan~ in the drnce. 3. Albumin to creatinine ratio a. B:I}"" Diagnonics mar~, a r~1II pad method of estimating an "'humin to en ratio (Clinitek Microalbumin ). Th. albumin .""c{ion is • dJ"'-binding method with oolor c.... nges .. pr=nting 0, 1,3,8, 15, and 50 mgldL. Th. Crt ,,,,clion is a ptrm:id..,,,,lih a=y with oolor rn:mge; ror ... ponding to 30, 100, 200, and 300 mgldL. When th. oolor change; are ,....d by rdl=anct photom~tly in a Ihy~r inS{rum~nt {Clinitd'J, an ~imated albumin to Crt mio is alruJ.ted. Th~ report.d units of th~ ratios v.ry: 300 mg/g = 300 J.l{;lmg = 0.3 mg/mg (or just 0.3). b. Th~ albumin as5ay is not s~fic for :oIbumin. Many oth~r protein! will r.-act with th~ dy~ including light chain" immunoglobulins, IJrmicroglobulin, T.mm_ Horsfall prol 5/hpf,:> 1+ heme reaction), and hemoglobin an bind to the reag.nt dye." Thus, "'m~ discrepancies may ha"" b.:c:n due to prot~in! oth" than :oIbumin binding to th~ reagent in the dip.nid,. 4. Comparison to other urine protein :waY' a. [Prot~in] mimated by rourine protein :u.s.ays of urinal,.. .. (i.e., the reagent pad method .nd SSA turbidity) rep...,..nu the rum of albumin and globulin con~nt"'tion'. Both method, detect .Ibumin better than most globulin" bur globulins do rontribur. to th~ reaction,. The detection limits of these: .....Y' vary (f.bl. 8. IOJ. b. Th~ SSA .ssay is :01'0 all.d the h"minlm beause it deteas :oIbumin better than globulins. %~n a .ample', r~,ult i, compared to .nandard solutions, turbidity can be detected .t .n [albumin] of 5 mgldL If. ""ry mild prot. inuria is aused by glom~rul .. diseas., albumin will be the dominant protein in the unn•. c. Th~ result. of these: routine prot.in assays are typic:dly not normaliud to • 'paoific gravity of I.OJ o. How...", their rerults ,hould be interpreted with knowledge of th~ .. mple', USG ... so that an estimated adjustm.nt an be mad •. In a ron""'ntrated urine ..mple in which microalbuminuria is detected aft .. norm:olization to 1.010, it v..ould not be unusual for common protein dipnick

8/ URINARY SYSTEM rractions to produce a trace or I + r~.ction or for th~ SSA :way to ha"" 1+ turbidity. C. Canin~ microalbuminuria l. Thu", h:IV~ bttn ~~ral pubJi,hal .bsu:>ets ptn:lining to th~ ""'" of th~ ImmunoDip Canine ten, but ""ry f~ pnr rting ability i, nNd.d, and .. pecially if ",nt,..] diabetes insipidus is ru.pect.d, ~ith~r H,O

..

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY d~prjvatjon or ADH ... porut {~m may k oonsid,,«I. B~u .. im"p'etation guiddjn~' =y diff~r wh~n spt~

Caco,

c.Jciu,

aragonit~,

v.{~rite

Cynine Oxalate.

C.rbonal~"P.{i{.

S CH, CH{NH,}COOH eac,o•. H,O eac,O • . 2H,O Ca, (PO.},(OH) Ca,. (PO.Jo(OH), Ca,. (PO" CO,OH).{OH),

c.lcium hydrogrn pho,!,hou

CaHPO,.2H,O

Cystine

c.lcium oxalau monohydm. c.lcium Olul.u dihydm.

Phosphat.,

B.,ic calcium phosph>te Hydroxyap"titr

Cystine Wh..w.llite

Wald.Uiu Apatite Hydroxyal"tiu Carbon 'l~aJ>'l{il' Brushite

dihydrate T ri",lcium phosphate Ocucakium phmpru.te M'4:ne1ium ammonium

Co.,fPO,}, CaH (PO.}, .2 . 5H,O MgNH,PO,. 6H,O

Whitlocki ••

MgHPO.·3H,O

Npeignificom amoum, of 10m. ion, _re missrd. (4) they lackal method. for detrcting >ilico and )" that llkction and romplttt an.ty.i •. In. &iob.i.dV I. Elliott I. od •. .IllA. VA M""oJ ojc.. ... ,.,.; F"'·_ N.,I-Ioo "'" U..iorJ, [" edition. 86-106. Ame,. 10... Stat< Vni...",;.,. P_. }S. Mdl';,d, 11. 1m. T.. II-J. ojU"-'"is .", &J, FIooiJs. l'hil.JdplO.. lippin=tt. Ra,",~. 19. 0 ....."" CA. Sttvtn. IB. 1999. U ....¥· A Qi,w.t G..NJ. '" c-.~p",;,", SIu....,,,, Miuion. KS.

um.+u.

-

c.. .....

. IR. 19I! l. q..;", U";"J a.. ......., "'" P.th.fby.;. iorJ, J!.onn." ~. KS. Vrttti""}" Medid~, . .. 0. Co/lina., .. I. Goldbtrr; HE. 1997. P,i",;,It, oj &1''''"'''"''''' BuIOolo. NY. lda.. .. 2. Wolf AV. 1966. ~ " '" s./..;"", .nJ JJ.J, R.Nk· "lim. c..",.",,.,,.;,, ~"i,,~"; C" "",,;_ T,J,i". N"" Y",b H~.

"J. Soodth.m SL ScoK MA. 2000. V~p.blid.cd data. ..... McC.ou;" T. Ro, LP. 1985. eo... ........nofloydro"""J'.~. 0""""""'J'. and Amt. N· M..Jtioti. SG i~ .. cimatioon.,( .........,.. 00DCt0'''''''''. All" Pacdi"", I 21. 185_ 188 . .. 5. Chu SY. Spout.. D. 198",. "-""",,,.,( • ...tid.ph .., ,,~o, foe wio''Y opocilK dtttm.i",tio~. Clio Iliochtm. 17.J-i-.J6. .. 6. IWF H. 1987. Gloea>rtiooOd i....ibi""" of ntid~ Reduced nicotinamide ad~nine dinucla>tid~ Ammonium Calculated mmolalil)' M ....... red osmolality Diffcrena: ~tw,""n measured mmol. lil)' and calculated mmol. rity Part;"] prclSllrc of carbon dioxid~ - log [H1 - log (IC.) wh~re K, is th~ ioniz>tion connam for a partially ionized acid Phosphate, all forms R~nin.angiounsin ')"lum Syst~mc International d'Unite. Strong ion differena: Sulf. te, all form. T mal :mionic charge Tmal body water content T mal body potassium come", Total body ,odium com~nt Total cationic charg~ Total carbon dioxide com~m Unm ... sured anion charge Unm ... sured cation charge Within th~ refc:r~na: imerval

[' I And tt..y m. y ~tc< loss (•. g.. to pleunl >nd peritoneal caviti.. ). In "'m< p. thologic . ..... involving muscle. H,O or .kttrolyt.. .run be""".n th. ICF :and ECF '1'>=1 (_ the ",," for d.tails). Fluids (•.g., pl .. m. Of urinnormal

.

HypermtremJa => Hypomtr~mi.

t

tbN a' tbH,O

=>

norm:d nonrud

tbNa ' i => tbH,O normal

~r

,l. normal

0'

t

,l.

I

...

or .,., ~r

I

(9. 1a.)

normal,l. I 0' I I ... ......

(9. lb.)

nornul.w. or i ,l.

(9. 1c.)

(9. ld.)

9/ MONOVALENT ELECTROLYTES AND OSMOLALITY

."

B. A mo.,"" acrur>U rdatio.nship is mo.WII in Eq. 9.ld. in which Na+. and K". r~p",""nt th~ ~xdtang~able N. + and K+ in th~ body {io.m bound in mo.b:ul .. a.. not exchan~able}.' From this '"')uatio.n. it em b. =n dut the total body ",crungeoble K'" coment influencu plasma [N . 1 . Thus, when hypokaJemift Sodium Con""'ntratio.n, Sect. V.B. 6). Hy~rkaJemia tend. not to cou"". significom hy~rnammia for two reasons: (I) a marked hy~rkaJemiry loss of isotonic fluid =y occur with vomiting. diarrhe., or sequestration. b. Renal loss of Na+ and H,O may occur in "",eral situations. {I} Many polyuric r~nal di..,.... cou.., Na+ and H,O loss beaus< of def=ive tubular functions. {2} Osmotic diuresis imp.i.. r~sorption of H,0 in tubules. A high tubular flow rat~ also contribut .. to Na+ 10... Tahle 9.3, Dixa.... and conditio"" that cause normonatremla in dehydrated or edeo,atou. animal. Net loss of isotonic fluids coming dehydration 'Aliment>ry loss..: vomiting, diarrh.,., 'eulic pressure in hqJatic sinmoid. {caused by fibrosis or venous rongmion} and loss of protein_rich pluma into th~ of Disse {sinusoids a", highly perm~able to albumin}. This cau~ .planchnic pooling of blood and 10.. of H,O across the hqJatic cap"we to the peritoneal cavity and thus underfilling of vaocular .p• .".. Mo",,_ ment of fluid from ""... Is decr""'

''''''ry,

9/ MONOVALENT ELECTROLYTES AND OSMOLALITY

505

inc""ast. hydraulic pressur~ in h~patic sinusoids, which l~ads to transudation, {2} H}'IX>"lbumin~m", .nd hypoprot~in~m", play =ndary rol .. in ascites furmation, {a} [n h~.hh, plasma prot~ins cr~.u colloidal osmotic (oncotic) pr..mr~ (about 80 % from albumin and 20 % from globulins) th.t hdps main H,O in v~ssds trull ..~ im~rm~abl~ to prot~ins. Wh~n hypoprot~in_ ~mia i. pres~nt with hq.atic cirrhmis, th~ increases in vascul .. hydraulic pressur~ h. "" mor~ dfry Joss: vomiting. diarrh~~. sajueslr.otioll. Gl.llin~ whipworm in!ttiion, ex", .. ..livation, bovill~ h~morrhagic bowd .yndrom~ '!kn. J loss: hypo:od",nororlici,m, proJo~ diurn;i" ~onuria, N. +. waniJ\i: IIcphrop. thi .., hypoaldon~ronjsm Cutanams loss: sw excretion of N.+ becou", of dec ....ed N. + resorption, Thi, is "'~n more in horses than other dom~nic mommals, {5} Hypm~nin~mic h}'ll'O'lldost~roni,m (Ott hyperkalemia) c, Cut;m~ous 10.. by sw~.ting {I} Among the domestic m.mmal., only hor= .wrat JUffici~ntly to cou", dectrolyu and H,O imWLonce" {2} Equin~ sweat is . Na+., K+., Cl-.rich fluid {concentrations.", gruter than pl:uma concentrations but ~poration may rontribut~ to the inc......),",· Drinking of H,O or th~ ADH.stimul.ted ""~ntion ofH,O .ft~r sw~~ting Im}' l~.d to dilution.! hyponatr~mia, d Third.space loss (typically loss to pleural cavity or peritoneal cavity) {I} ~.ted drainage of chylou. thoracic effusions (a) R~peated removal of ilOtonic fluid &om th~ thoracic covity probably r~sults in. N~+· and H,O-dqJleted nat~ that is followed by intake of H,O and.n ADH =pon,. to come dilution.! hyponatr~mia,"'" {b} This 'YJl N.+ r~t~ntion) with or without ed~ma a, Edematous disorders {I} Congesti"" h~~n f.ilur~, hqJatic cirrhosis, . nd Mphrotic syndrome {2} Although th= conditions .re oft~n """",iated with normonatremi. {Ott th~ preceding sect, [V,B,2l , hyponatremia {typically mild} may also occur if th~ ratio of tbN.+ to tbH,O is decreased. b, Expanded ECF volum~ {but without «Iemo} {II Syndrom~ of inappropriate ADH "",,,,,ion (SIADH) {aJ This is chara.ct~riud by nonphysiologic rei..... of ADH in th~ prestnce of hYI""',molality and hypervolemia, Excess ADH with unr~strict«l H,O intak~ l~.d. to fiN.H,O ",""rption and dilutional hypon. tremia, R~nal N.+ excr~ion (perh. ps due to ANP) is incr~...d becou .. of activation of mlume receptors,'

508

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY (b) Nalfologic, pulmon.,y, and thyroid di""rd~n ar~ ow;oci>tffl with th~ 'rndrom~ of inappropri.te ADH ''"''retion, ••• '" many drug•. A f~ cast. h:IV~ oon reportffl in dome'tic marnn",],.'" {2}

fu~sivt

administration ofN.+_poot Huid.: Administration of 5 % dalro .. or 0.45 % ..lin. could lr.d to a dilucionaJ hyponatrrmi .. {3} Primary polydipsia moy cau.. hyponatremia but typically js • minor abnormality b.COUst funcrional kid"q' Gm nertl< Ih. oonsumal H,O."

3. Shifting ofH,O from lCF to ECF •. A markffl or ""n;sunt inc"",,,,,, in dfa::ti"" pla,ma o!JI\OJality (t.g., b«au.. of hyprily by th. princip:d ~ll, of th~ coll~cting tubules (Fig, 9,3), Aldost~ron. promotes this proa:ss by stimulating Na+_lC'" _ATP,... in th. bawlat_ u :d m.mbran~ ,nd o~ning lumin:d lC'" chann~ls, Hy~rk:d~mi. ,nd angiot~nsin II a" th. major ,timul:mt, of :ddoneron~ ,,,,,,,tion, Mr"lOOOrticotropic hormon~ (ACTH ) and hyponammia:d", ,timul.t~ :ddoneron~ rd~=, but the df"'t of hyponatr~mia is diminishM if th~ ~f&ctin blood volum~ i, adts or other bretds of dog•. {2} Thrombocytosis" (a) K+ is ,de= I.OOO.'Ithog.nesis of th~ hypokal~mia of chroni" ",nal f.ilu", is unknown and may b. du. to muhipl. factors: inc",asrd .. nal K+ exc .. tion, incr",...! colonic K+ exCl"~tion, .nd d""",asrd di...: ary K+ int:ok~. lkaU,. cats main .. nal cona:ntrating ability much longtr in r~nal di= than oth~r domestic mammals, possibly th.ir distal tubul., .. main ... pomin to aldon.ron. during hypovolemia and thus retain Na+ and """'~t~ K+. In ""prrim.ntal conditions, a N.CI_restrictffi di...: did result in hypokal~mi •• nd inappropriat~ kaliure;is wh.n th~ glom.rul.. filtration rat. was rffiua:d.'"' {2} HypokaJ~mic myopathy in Burmese kin~ns""" (a) Th~ Burm.,.. kin.ns had hypokalemia, mu.de wukness, .nd high .. rum cr~atine kin..., .ctiviti.,. The myopathy ~ pr""ipitatffi by me .. or ",erc,s,iv:nion Defsal intah of Cl- vi. or:d or N administr>tion of 5Olutiofll containing Clmay :dso le.d to hJ'P"rchlo""mia, b, Decreasal ""nal acretion ofNa+ {hJ'P"r:ddost~roni,m} (r>r~) {I } Ex~ivt aldosuron. promot~. a~ivt ""nal Cl- {and Na+} ret. ntion, {2} HJ'P"rchloremi. (.nd hy~rn.mmia) may tory alkalosi. {chronic} a, As. com~nsatory change to prolongal hypocapnia and alkalemia, the renal retention of H+ is incre• ..d and thur th. renal consc:rvation of HCO,- is raluced, b, Th~ fall in HCO,- is Wlanced by.n inc""... in ct and oth~r .nions that ."" not id~ntifiw, " Dehydration of the sampl. (~.poration or sublimation): Exposure of .. rum or pla!ma to . ir may :dlow ~poration th. t auses hJ'P"rchloremia, This is especially true of air-conditioning systems that blow cool dry air ovtr the sampl. proassing or ana!ysi. areas, Sublimation of H,O from frozen sampl.. may au", hJ'P"rchloremia.

Normochloremi. : Recognizing the p" ",n"", of normochloremi . may k important when or decreased ",rum [HCO,-] is pr... nt, because it sugge;ts the preslrtion, a f. ll in [K+] in th. EC F promo". th. mov~m.nt of K+ out of th~ ""II :md tho mo""m.nt of H+ into cdh. T he higher intra""lluiar [H'] .Iso promoles W sa:retion by ren:d tubuJ .. cdls and increa=! goneration of HCO,-. thu, promoting :dblemi .. 3. Administration of sodium bicarbonal~. organic anions thaI gtnerate HCO,- , or magnesium hydroxide in ruminants or hone. a. Ex=< .dministration of sodium bicarbonat~ (whiJo t",ating acid.mia) m.y incr.... s.rum [H CO,-].

9/ MONOVALENT ELECTROLYTES AND OSMOLALITY

531

b. M",.boli,m of som~ org:mic anions {~.g .• l_lacrat~ :md cimll~} by h~patocyt~. I.... and pathogtneses (T.bl~ 9.1O) I. G..nuation of ""(".« Tabl. 9.(2) D'""....«I renal ""cretion of H+

'!knaJ

f~ilur.

'Urop",itoncum or urin.ry lract obnruction Di,ul .. nal tubular acidosis {cyp. I} Hypooldo,{croni.m lnn"ased HCO,- loss 'A!imcntory [SSt.: di:orrheoo, ...quc'tration, or vomiting of ""oCIutic KCrclions Iknalloss." proximal rerud tubul>r acidosis (typo 2) Dilutional ""idosj, (npid infusion of 5alinOnffi in • mar., but th~ om,. was not d~t~rmin.d." 4. Dilutiorut! .cido!is m. y occur with rapid s:din~ infusion, which may dec",as. [HCO,-] by diluting ECF HCO,- . How.""r, .bsolut~ chang. caused by dilution is ""rectal to bt minor .nd thus cau.., • minor ch.IIV' in blood pH. S. In vitro loss of HCO,- from th~ .mpl~ {ott Bicarbon. u Con",ntration &ct. II.B.2} C. Decr~a.sed [HCO,-] or [rCo,] with hy~rchlor~mia: HJ'P'rchlo .. mic m~ubolic .cidosis mongly mggests th~ prestn", of .. rut! tubular acidosis, ~ith~r th~ proximal or distal form. \. For proximal .. rut! tubular acidosis, proximal tubular di ...... rffiu= tubular secmion of H+ and decre;;ose; rons ..v.tion of HCO,-. As shown in Fig. 9. 7, proximal tubular HCO,- coruc:rvation normally I..ds to th. mov~m.nt of HCO,and Na+ ions from th~ cdls into th~ int~rstiti:.! fluid .nd blood. IfHCO,- ions.", not bting formffi in th~ proximal tubular ",Us btcat= of inhibition of carbonic anhyd .... , th~ Na+. K'.ATP ... pump cr.... t...n dectric:d gradi~nt that ~nhan= Clre;orption. Th. n~t result is decrea=! [HCO,-] , incr .......! [Cn, and ther~fo .. hJ'P'rchlo .. mic meubolic xidosis. 2. For dist:'! ren:.! tubul .. xidosis, disul tubul .. di ..a,. impair.; the secretion of W and thus d= ..",s th~ gp lJUy ocil. C. ubolism of ..cb gluros< molecuJ. remit. in two Prruv>t< moko.tl.•. ....., H' ions. :ond • net production of two ATP molecules. WMn tbe", is >..). Tn. pK.. of bctic:acid is 3.1. so nearly :ill of th.. bClat. produced ",m:Uns in ti>< :anionic form: very ~tde buffen H'" fOnn I>ctic :acid .. phy>i_ ologic pH v:ol..... k aplained in th.. text. tho ""idemia in I""tic :acidosis ",...ed by • ....,robic conditions come.! from th. .... of ATP (whim produas H1 fOr en< rebtionsbips of tboo< molerult~ dehydrog~n ... ~nzyrruotic methods. Th~se ..... Y" ar~ not commonly availoble in clinical l.boratories. C. Unit: mgldL X 0.112 = mmollL (SI unit) (Nou: Thi. i. a conversion for th~ .nalyt~ lactote. Th~ conversion factor for lactic .cid is 0.111.) D. Sampl~ for [L-lacute] I. Blood .an'pl.,. should be p~ or .nalyz.nl quiddy so that l_lacute produced by ~JYIhrocytes does not inc",... th" plasma [L-lactot,,]. If the sample c;onnot be p,""""ssed immediatdy. L_lactau production am be reduced by collecting blood into a tub. containing sodium fluoride .nd chiUing the blood until th. plasma is "'Parated &om th~ ~rythrocytes: fluoride inhibits phmphopyruvate hyd .. rase (.ynonym: ~nol ...) of the glycolytic p:uhw:oy. 2. Id..lIy. blood should be collected from fr..,_f1owing blood (without. tourniquet) '" that blood nagnation doe. not rs cycle .uch th.r the . erobic production of ATP is defective. Generation of ATP switch.. to an""robic glycolysis. which produ= L.-laaar.." ~ {2} Pyruvate dehydrogen= deficiency in Sus=< spaniel. and Clumber spaniels =ults in excess rorm>lion ofL_lactau. " '" Pyruvate ddtydrogI physiologic pH value!, n •• rly all of Ih • .., mol.cules a,. in Ih,;, anionic form •. B. K.togmall (I nm to I J.IDl ) to ~ ... d~d out by gravity. Molt oncotic pressur~ of plasma is mu.a! by plasma pro{~n, (.bout 80 % albumin and 20 % globulint ). Pan of th. rolJoidal osmotic pr...!Ur~ i. mributa! to mtion, (•. g.• N.-,) that are attracta! to th~ nq:ativdy charga! pro..in. (Donnan ~ui/jbriu", iffitt).

9/ MONOVALENT ELECTROLYTES AND OSMOLALITY Table 9. 15. Solutco that contribute frovided fO oin'filfy conceft)

Solut~

N,> K> ct HCO,-

UN Gluco..,

PO,

.c." Me" Prot~in

fO ""'"""

oomolarity (approximate conccnU'lltion.

M=urw conc;.,mntioll

Factor to oollven to mmoJIL

Comributioll to osmolarit!:

146 mmollL 4 mmollL 107 mmollL 24 mmollL 20 mgldL 100 mgldL 4 mgldL 10 mgldL 1 mmollL 7 gldL

" "" "

>46 mmoUL ) 4 mmoUL 107 mmoUL 24 mmoUL 7 mmoUL } 5.5 mmoUL 1.3 mmoUL } 2.5 mmoUL 1.0 mmoUL < 1.0 mmoUL

TOial

-t-

2.8

.X 0.32 " X 0.25

"

Varies with

prot~ill

547

Contributioll to toul osmolarity ill Krum of h.. hhr :mimal 281 mmollL 94 % of tOial 12 mmollL 4 % of tOial 5 mmollL 2 % of tOial

5OJUt~

solut~ solut~

No significant oontributioll

299.3 mmoUL

Mon nonprot~ill ..,lutes do nOi comribute to osmotic pr=ur~ ill capillari... btCOUK th~ copillari... are p"rm.. bl~ to H,O and th~ ,mall solutes. Chapt~r 7 oollu ins illforma_ tioll regarding th~ m... u",m.nt alld im~rp"'tation of colloidal osmOlic pram..". II.

Phy.iologic proce.... A. M smw ill th~ foregoing d~finitions. oUIlolality is th~ collc;.,ntration of ",lutes i"" kilogram of solv~nt and d'p""d. 011 the numb.. of mol,""ul .. or iOlls in th~ ",lutioll. Th~ major oontributor.s to ..,rum osmolality alld th~ir rdati"" comributions a", liuw ill Tabl~9.15.

B. Major COIlc;.,ptS of rdati"" oontributiollS of solutes to Krum oUIlolality I. N a+ is th~ major solut~ ill .. rum. About half of th~ solute {mol.., not mass} ill .. rum is actually Na+ iom. 2. Cl- runs a do .. sa:ond. B=UK Cl- f"' 350 mmollkj: or [Na1 ::> 170 mmollL).lll H,O I...ves ""lb. including neuron •. Con..,· qu.ndy. the :miJrulI can be dep=sed. stuporous. or ~vrn die from the hyp"rosmol:u nat~. (b) How"",r. if the hyp"rosmolar nat~ develops slowly. th~n intracdlul>r production of org.nic mol«:tJ.I .. such as taurin~. glycin •• glutamin~. K1rbitol .nd ino.itol (so-callw idiog~nic osmol..) diminish .. the osmotic gradi.nt •• nd thutle .. H,O I• • ves the ceU. [fhypotonic fluids are then administ~rw to reduct the plasma osmolality. there am be a rapid influx ofH,O into neuron. and d.-vdopment of ctr~braled~ma. (2) D~t~rmining physiologic r.. pon... th.t are expectffi in azot.mic animals (a) [f the hyperosmol.lity is cau..d by inCl"~a.M ur... ronctntrationl only (i .•.•• ff«tivr osmolality i. not incr .....d). th,,~ should not br a nimulus to drink H,O or rd ....., ADH (unless hypovol.mia is prestnt). (b) [f the hyp"rosmolality is due to .ff«tivr K1lut .. and not ur .... the hyp"rosmolality is upected to stimul.te thirst and ADH rd ..... . Ill.

Analytical conctpu for mmolality (sre Chapt~r 7 for colloidal osmotic pressure) A. Osm.. l. Osmom~try is based on phy.ioch~mical prop"nies {called ('tI/ligatiw propntin) that dep"nd on th~ number of particl.. in a solution. Tv..o coUig.tivr prop"ni~s are u..d in clinical osmometry:

9/ MONOVALENT ELECTROLYTES AND OSMOLALITY

549

a. Fruz.iIll:-point dqH=ion: A I mol/kg solution of. solut~ in H,O (I molal) wiU ha"" a !'n.tting point 1.86·C low~r than th.r of pur~ H,O. b. V.por pr~ssut. (or dew point) d.prossion: A 1 mol/kg solution of a ",lut~ in H,O (I molal) will ha"" a vapor prossu", 0.03 mmHg lower th.n th.r of pur~ H,O. 2. Frttring_point o.momrt~ ...", mor. rommon. mo .. prec~ •• nd mor~ acrura" than vapor pr=ur~ osmom~Urs. Vapor pressur~ osmom"'~'" do not m~a.ur~ th~ contri_ bution of volatil~ solutes (• . g. •• lcohols) to total osmol.lity. (Not~: Colloid osmom_ rt ... mrasu .. rolloidaJ osmotic p..ssu.. and not osmol.litj'". = th~ Colloidol Osmotic Pr~.. ur. section in Chapt~r 7.) 3. Osm. indicates th. total ron""'ntration of ",lut.. in th...rum but d"". not indicau which solutes "'. p.... nt. 4. Serum i. th. rrquiral sampl~ for m.asuring osmolality; th•• ddition of antiroagulants for pl.,m. samples would be: adding solut~ to th. plasm>. Th. st.bility of a .. rum osmolality will dq> is in"",,,,,",,. bea .... the ""ogenous wlu.. inc"' .... the Osm. but is not included in the Osm,. formul .. E. When hypooomob~ty i. coused by bypona~mia:and hypochlor..intoo PT. G...... CEoGknom LE. ZOOJ. lDbac bo~p~al, i~ • MiDi""", .'iduu.."" ...ith hypodipoic h,~, . I Am Y.. Mod Auoc 223, 178}-1787. S. IId.dm SH. B.nto. S. 1996. Acutt lymplooblastk Jruk..nia. hyr=tktmia • ...d p"..,Job1P""bt..ni. in • doJ:.) Am V" Mod Jw.oc 208,151- 239. auib." to......boli< acid.ooi. io dianlook al_ I N.", l}lo212S-2[J1. IO! . Ewudo.k IB, N.yIoo 1M. z,,1Io GA. 2OOl. Anioo &"I' "",..Lo" • ..;t!o ..... m 0. ond DL.-Ioctat< «>D«n".rioo in dianlook _ oat aJv",. J Y.. 101.. 0 Mod 17,940-942. 101. Poch, RA. Cohn IA W~~lotadt .. DR. SIooh... GD, N. ..... 1M, Zdl GA, E..ad.v.k lB. Williamo DA. R.""" CG. O's. .... Dr. 2OOS. D_lactk ocidooi. a .... 1m and M., 1999. C.O Y" I 41,70}-707. lOS. au';""""", M'\l . Edfd,d, IH, E"... JW. 1990. Pro"yl"" pyool iov rtioD ca •• ", D·lactk ocidooi •. Ub Im'''' 62,)1 4-118. 106. Sa0,0

p.co, p.~ p.~ p.~

P~

pH Plo, P~

PO, Po,:>P~ P~

S.o,

SID SIDa-.....-. SID,_ SID. So, Sp~

tCO,

"SA WRI

SOl

Conumralion of x (x = an. lyll" oX)"g~n lension gradiem Sum or IOI3J of nonvolatil~ ~k acids Base exc;.,,,, in blood Base exc;.,,,, in exlrac;.,J]ular fluid Base exc;.,,,, in plasma C"bon monoxide G~u. arbon dioxid~ C"boxyh~moglobin

phosphate

Biarbo""l~

Hemoglobin D""xyh~moglobin

(rffiuccd hemoglobin) Hydrog~n phosphate 0xy\:"n comem P.rtial pressure of carbon dioxid~ in .ncrial blood P.rtial pressure of :olva>lar arbon dioxide P.rtial pressure of oXJ'C"n in m~rial blood P.rtial pressure of :olva>lar oxygen Pmial pressure of carbon dioxid~ - log [W ] P.rtial pressure of inspired oxygen Pmial pressure of oxy\:"n Phosphal~ including PO.:>-, HPO,'-, or H,PO,Phosphate Pmial pressure of carbon dioxid~ in ""nous blood Pmial pressure of oxy\:"n in ""nous blood P~rc;.,m h~moglobin 5aruralion with oXJ'C"n in m~rial blood Sirong ion diff~ren"'" Sirong ion diff~ren"'" using rorr«lal chlorid~ conc;.,n1ralion True sirong ion diff..~nc;., Sirong ion diff~r~n"'" alcu!.tal using x slrong ions P~rc;.,m h~moglobin 5aruralion with oXJ'C"n P..c;.,m h~moglobin 5aruralion with oxygtn of mcrial blood by pul.. oximetry ("pO i, fOr "pul .." oxim

W + Heo, "

H2C03 ~H20 +C 02(g)

~

,

" ,, " -',," -- , , "" , "

I H+ from metabolism

D. Metabolic alkalosis ----------------------------- 1,-,

- -

" ," ------------------""

~

E Respiratory alkalosis

f I

w+ HCO,

H,CO, _ H,eJ •

C02(g) expIred ~-~

- -

~g )"

" ,""

- ..,.'-

'- ,

, """".. ,, "" ,, "c ~

101

BLOOD GASES, BLOOD pH, AND STRONG ION DIFFERENCE

563

l. Bwm.. blood [H+] is ""I}' low romp.=! to [HCO,-] (mio .. 1:600,000), thi,

p""""ss does not low~r [HCO,-] unless thu~ is ace .. i"" g~n~r;Uion of H+, 2, It may ~ hdpful to con!id~r the bicarbonate ,yu~m going through H,CO, (Eq, 10,20), but th~ .ctu:ol reaction catalyud by c;orbonic .nhyd...e invol""s the diswciation ofH,O, rdease of H +, .nd r....crion of hydroxide ion (OJ-t) with CO, to form HCO,- without. H,CO, int~rmediat~ {Eq, 1O,2bj, Th~ .. ""tion is =",rsible, H + + HCO,- H,CO, H,O + COl((}

(IO.2a.)

H+ + HCO,-' ....... .......... ,H,O+ C O ,{, )

( 1O.2h.)

B, Hyption, [HCO,l ,..,will WRL

-=,..

564

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

Inspired Air

Tracheal Air

PIo,. 159 nmHg PIco, ....... 0 mmHg

Po,. 149 mmHg

P"o,-l00mmHg

Alveolus

Expired Air

P..,o . 47 mmHg

PAco, . 50 mmHg

PEco, < 50 mmHg

0, Venous Blood P~·40mmHg

-----------------r, ,

co,

P.,co,. 45-50 mmHg

Arterial Blood

,

P. o,_l00mmHg

,

,,

P. co, • 40 mmHg [H+) • 40 nmoIIL [Hea,l • 24 JT to Hgb (O,Hgb) to u,=t< th. oxyg" in metabolic path"l>}"l. • CO, (from "",ubo~c p>thw.ys) diffuse. into pl .. ID1 10d then into . rythrocytos. Vi. tbe carbonic :mbydn>< (Gf) reaction, CO, and H,O .,. ron",,""" to HooJ-:md H·. 1be HCO,- moves to pWm1 in uclung. for CI-. Most ofthe W is buffered by the d.eoxyg.ted Hgb. Th. 00, proth>t< .ligbtly in H gb molKuks. [2.3-DPGI difforen=. and 0...... foe.o.... Accordingly. tho diffe .. ..,. hoca.... of diffe .. "",rago P" values (P,o, ..... n homogIobin is SO % ...",... od with oxygon .. pH 704. 37 'c. and oW mmHg P,co,) differ: oor>es " 25 mmH g. ",ttl. .. 26 mmH g. peopt. .. 27 mmH g. dogs .. 30 mmH g. rnd c. .. .. 34mmH g......

..,=

101

BLOOD GASES, BLOOD pH, AND STRONG ION DIFFERENCE

569

c. Som~ blood ga> instrum~nts calculat~ th~ So, from m.... surffl pH, p.co" and P.o, v:olu .. by using fOrmul:as that an~mpt to corr«t for umpentur< var;"tiom ~nd a compla formula that an~mpu to describt th~ 0, dissoci~tion curve.' Th~ colcul.tal So, m.y bt ~rronn>us btcaus. of ,,",umffl normal 0, .ffinity for Hgb and """mffl normal [2,3_DPGj.' {I} If th~ pH i. constant. but th~ po, d«r ......., th.n So, d«reases. {2} If th~ po, is ronnant, but th~ pH deer ....... (acid.mia), then So, d«r= If Po, is COlmant, but pH incr..,...,. (alkalemia) , then So, mcr ......,.. 8. PAo, (in mmHg): alveolar 0, pre ...... re {sometim •• abbreviatffl :as A} a. PAO, is the pani:ol pre...... r< ofo, in the :olveolu air (g:as). Two fOrmuw incor_ por.oting Flo, .nd P,co, con be uKeto", for inc..asing tempc:ratu= .'" in T.ble 10.2. For exantple. if the Peo, wer. 40 mntHg at 37°C. then the Peo, would be: 44 mmHg (40 + 10 % of 40 mmHg) at 39°C and 48 mmHg (40 + 20 % of 40 mntHg) at 41°C. 3. The", are differencu of opinion and unan.,...=' qu .. tions regarding the need for tempc:rature correction of blood gas. a. For example. lowering blood'. r.ntpc:rature {as in hypothernti.} will lower the Po" but the 0, content of blood will not change. In the hypotherntic sme. is thelow.. p.o, value d .. ired for the lower metabolic rate or should the p.o, be: incr......d by incr.a.ing the Flo,? b. If r.mpc:ratu .. _corrected values .'" used to ntonitor a p.tient. and if the ""ti.nt·s lxxIy tempc:mu", chang... will ch:mgts in pH. Po,. or Peo, be: c;>UsN by changes in body tentpc:rature or other f:>eto",? 4. If. loboratoty .. ports tempc:rature-corrected values. it mould also report the valu.. measured at 37 °C. If all in vitro valu.. are reported at 37°C regardless of the body r.mpc:rature. then changes in Po, and Peo, values will reflect changes in 0, .nd Co, content of blood.

T able to.2. Correction o f hlood gas and J:!H valu .. for variations in bod! temperature

'C

'F

,H

"40

105.8 104.0 102.2 10004 98.6

- 0.06 - 0.04 - 0.03 - 0.01 None

39

"

37

Not will I,.... 6. Excessivt h"".rin in the coU""ting .yringr con r.. ult in erronww valu.. ; there should only b. enough h"""rin to oo;ot th. n...dle and. 3 mL syringe. Thi. can b. a.coompli,hed by drawing 0.5 mL hep"rin into. 3 mL syringtory r.. parnes.

Fig.

respiratory or metabolic .yst.m, han romp"nsatro apptopriatdy. [f the data indial.1< that an .nimal has not achi""'" up"cted comp"nsation, th.,. may indicate the following: a. The animal has not had time to romp"nsate. Thi, i, e'p""i.Jly true of "nal comp"nsation for .cul< respiratory di""rdw;. b. Th •• nim.l has mo .. than one di""rd" that is alt..ing the ocid.ba.. statm, and thi, disorder is preventing .n expbolic acidosi, For e;;om mmoJIL i in [Hea,-] in: M~ubolic

fupffi"cd p.CO:! chan~ (mmHg)"'

t

0.15 (O.04--O.20)

i

0.35 (O.29--O.43)

,l. 0.25 (O.14--O.36) ,l. 0.55 (0.43--O.76) ,l. 0.7 {O. 5-1. I}

i

alkaJosi •

0.7 (0.5-1.3)

• &peeteCC< b.~ "",. mred and ap< l. Compo.rM to th~ .dult horst. a foal at birth hal lower P,o, (< 40 mmHg) and higher P,co, values (> 50 mmHg) durillg iu first few hours. The P,o, incr~,.,es quickly to lIe~r adult values by I d of age, .lId th~ P.co, slowly changes to adult ""lues by 4-7 d of age. 2 Similar p>ttems ~r~...,11 ill netmatal calvt •. The p.o, approxhes ~dult value. by I d of~, . lId the P,co, appro.ches adult values by 2 d of ag~. 3. Plasm. [HCO,-] values are .lso g=ter initially, corresponding to th~ gre.ter p.co, p=sures.

IIW""".

n.

Hypoxmtu. (d«r.-ased dissolval 0, ill blood; d«",ased p.o,) =y cause hyfH'Xu. (decr.-ased 0, ddivtry or utila.tioll ofo, by tissues), but the", ..~ other disorders in which thue i. hypoxia but 1I0t hypoxemia. The diff~relll types of hypoxia call b. divided illlo sev~1I groups." Hypoxemic and hypoxic disorders or oonditions .lId the apected laboratory data for hypox", disorders .'" lined in Tables 10.9 and 10.10. A. Atm~lph"ir hyfH'Xi/l; inhalatioll of atmosphere that has d«",ased 0, oolllelll {e.g., high altitud~, allesthetic problem, or ill an airtight box} I. The inhalation of atmmphe", that has d«r.-ased 0, colllelll COII5ge will dec ..... with illcr....ro collcentrations ofCOHgb or mffhemoglobin. C. III ho ...., the Spo, ulld .... timated the S.o, by.n average of 4.4 % whell S,O, was ~ 90 % and ov..estimated the S.o, by.n averat:e of 4.1 % whell S,O, was" 90 %.l1' The erro .. might ~ due to diff... nt prop'ni.. of .quine blood compared to humall blood. D. III dog, with S,O, of~ 70 % , the avrragt difference ~tw..,n Spo, and S,'" was about 3-4 % {e.g., Spo, of 87 % .nd S,'" of90 %}, dep'ndillg 011 applicatioll sit. (tollgue or tail) alld type of pro~ {ear or fillger}. The ...son for the diff..ellce is 1I0t known." As with the equine dot>, pul.. oximetry ulld .... timated the S,.o, when it v.as high .nd o""... timata! the S,O, whell it was low.

STRONG ION DIFFERENCE (SID) AND STEWART'S METHOD OF ACID_BASE ANALYSIS I.

Ev:duation of dectrolyte relationships led to all .hemate mffhod of assessing m=bolic (lloll... piratory) a.cid_b ... disturballce. (Stew:ln's quantit.tive .nalysis of a.cid_b ... chemistry) .nd the calculatioll of SID. A complete description of Stewart'. method .nd SID COllcepts is beyond the 5COp' of this book, but major asp«t. alld a compariso" with mo", traditiollal a=ment of acid_b .... disorders is presented. For a complff. allalysis of Stewart'. mffhod .nd SID. additiollal ..f..en= should ~ studied.""" III Stewart's method: A. Electrolyt. disturballCe! are approacha! ill the context of phy.iochemistry with consideratioll of equilibrium equations, con.. rvation of mass, alld balallce of charge.

101

585

BLOOD GASES, BLOOD pH, AND STRONG ION DIFFERENCE

B. Nontraditional ddinitions of ""id, and balO; ar~ usM. C. All da::trolyu. in biologic fluids >r~ considorw to b. involval in acid.b..., WLon"" and Jrulintenan", of d'""tric;;d neutr:dity i, uf"""Iw (Eq. 10.8a). [N. +] + [K+] + [f-, lacute, act:l"""'t>t~ . p.hydroxybutyrate, othor acidic anion. of m~uboli,m, and uOg-] + [Alb~] +[POr] ) - ([W ] + [NH.1 ) .trong cotions - strong anion. = w~ak aniom - wuk cotions [fSID,_ = "rong cotion. - 'trong anions Th~n 5[0_ = weak anions - w.... k cotions 5[0_ = ([OH"]

+ [H CO;] + [CO,>-] +

[Alb~]

+ [PO.'""]) -

([W]

+ [NH.+])

( lO.gb.)

(1O.8c.)

D. Analyees involvw in acid.~ bal.n", ar~ consid..al to b. e ith~r independ~nt or depend~nt variables. l. Th. independ~nt variabl...re those analye .. that are regulatrd or chang..! ind~pend~ndy of oth~rs: Peo" SID, and Arm (= th~ ddinitiom in th. nat "",,tion). 2. Th~ depend~nt variabl.. are thOR .nalye.. that chanets :as St.wart. loI Sin~r .nd H.ning,"': ddinw buff.. w,.,. which i. id.ntical to Stewart'. S[D.'

SID l""mic or dilutional

i ct-

HYP"rchloremic acidosis

"

Non.' Variable"

Mec.bolic .cidmis :md i [uSA]'

" ""

,l.

p.co,

;

; ; SID/SID,'

"

"," ","1WRl "

"It

"",;..bl. chmg.:

in

Na+

R.spiratory acidosis

Hypoolbuminemic . lblo,is

.lblo,is'-

acidosis"

Metabolic .cido.is and

i

[uSA]'

"

• If byptions of two ions m.y cou", a mixffl acid· b.... disord,,; for n:lmp[~, [ms of plasma H 2 0 could result in concurr~m hyper"". t .. mic alkalo,is and hyperalbuminemic acido,i., Th~ roncurrem alkaJosi, and acidosis in th. Suw:m method rai,es th. question of wh~th" th~r~ is noSIO",i, ,1O VI.

AI ru:omm~ndffl by lOm~ authon, SID valu~s should ~ imerpretffl with routine blood gas valu .. (pH, Peo" and [HCO,- j) to d~t~mlin. whether th~ ani"",l has an acid. b"", problem and wh~her th. probl~m i, respiratory or nonrespir>tory (metabolic)," Jl If the probl~m is • nonrespiratory acid. ba", disturb:ma., th~n th. contributions of nonbiearbon. at~ dectrolyt .. con bt explorffl with Stewart's method,

VII,

Prior to th. propoord USf of the strong ion theory, an und~rst;",ding of:m :mimal'. acid. ba.. :md rlectrolyte disord~r was obtainrd through the interpret.tion of pH , Peo" [HCO,-] , BE" [N . 1 , [K'] , [Cn, :mion g' P, .nd albumin ron""'ntration (Itt th~ prrcrdiIll:

101

BLOOD GASES, BLOOD pH, AND STRONG ION DIFFERENCE

591

Acid_B... Abllormaliti.. =:tioll .lId Ch ' pt" 9}. Evalu.cioll of such illform>tioll h ... provid.d . lId wiU comillu, to provid••11 ulld.malldillg of all ,"imal', pathologic nar..

VIII. Tho.. who study SID theory alld its . pplicotioll star. that th. SID .pproach r"'luir.. 'J>'Ci..-spa;ific valu .. for ATQT; th.c is, the sum of the colI~m .. tio", of 1I0IlvoJ.til. buffers, .. rum or pl ... ma proteills, . lId PO•. " AI; st.ta! "'rli" (ill Ih. pra::.dillg sea. 1l.B.5) .lId ill Eq. IO.II e, pl ... ma Aror collsists primarily of th. variou. alliollic forms of PO. alld proteills {albumill and globulins}. A. Th.", h . "" bn.1I art.mpu to calrul. r. pl.. ma ATOT valu.. for h",lthy cotd.,"'" dogs!' cots," alld birds." Th. calcuJ.t.d valu .. (mnll ± sd) w... obtaill.d by u.illg ",ttlu from ollly to dog., 10 cou, 12 pigwll', alld 9 colv.. (or pool.d bovill•• lId oville pl ... ma) . For most of the dola, the variatiolls ill the calrulot.d pl ... ma ATOT valu .. .. p.... m the a pect.d variations ill pi.."", proteill alld PO. colI~mralions ill such samples from healthy , "imal •. B. Usillg Ih~ calruJ.ta! me.1I pl ... ma Aror valu...lId m... ural [HCO,-], all SID value COli b. calcttlal.d (Eq. IO.llc). However because ther.... biologic variatiolls ill Ihe ",rum COllctmratiollS of PO. and pror.iIlS, a mean Aror value may 1I0t b. . ppropriate for all heallhy allimals . lId will ddillitdy 1I0t b. . ppropri. te for :mim. ls thaI ha"" abllormal pror.ill .lId PO. collctmratiollS. Also because of the lock of "l:retmem ill ""'"y dillical assap, pl ... ma Aror values calculot.d for 011. set of assaY' may 1101 b. appropriar. for . 1I01her set of assays.

Reference s

.I""""',......

t. Hruod. JW. Soot< MG. 1?99. Pb,oOol+] i, th~ ponion of [rCa>+] th.t is hormon:dly r~latM .nd contributes to pathologic sUtes. b. Anion_bound c,>+ {I} Bound to anionic prot~ins: About 40-45 % of tC~JIivdy ch ..gffi sites on prot~ins {80 % to :dbumin .nd 20 % to globulins}.' Sinct binding is charg. d.~nd.nt. changes in blood pH slightly :dter c,>+ binding . nd thus .+ ktwttn bound .nd frtt fractions. {2} Bound to nonprot~in anions: About 5- 10 % of tCa" is bound to citr>l". PO, . loct "'~' .nd oth... mall. diffusibl~ .nion5. 2 U.ing a filtration 'Y"lc/",u to contact bon. m>triI, or to mManct' stimulate osteoclasts to degrade bone by.nzymatic digtnion and acidifje>[ion." b. Vitamin D enh.Dces Co" r=>rption from bon. by promotiJll: ost.ooa,(ic 'Clivi!), and by .nhancing =pon.., to PTH." c. Calcitonin blocks ostroclastic ostwlysis through dir""t changes in ostroclasts and by reducing activation of os{rption through th~ form.rion of calbindin, a Ca .... binding prouin in th. dinal nqJhron. b. Angiot~nsin II nimulot .. th~ resorption ofN.+ in th. proximal tubul~, v", a Na*. Ca>+ ootr.mpon ,ysum. Ca'" i, concurr~ncly r~,orbed. Co.'"':md PO, inur>ction. I. Th~ [lei+] and [pO.] in pla,ma ... gr~at ~nough in h~althy animals th.t C.,{PO, ), complex.. would form if inhibitors "-"lbumin~m", when Ihe animal does not h :IV~' defect in regulaling Ih~ [fC~""'] . To eslim'l~ Ih~ dfecl of lower prol~in and :dbumin concemralions, correction or adjusling formulas h. "" bttn proposed. I. Canine adjusIM [ICa""'] considering :dbumin con",nlralion (Eq. Il.l a)' 2.

Canin~

~n:rz.o

.djusted [rCa""'] =

m~~IUr..d

[ICol+] _ m.... surM [:dbumin] + 3.5 {± 1.3}

(11.1a.)

Example: If [ICa'1 = 8.0 mgldL &: [:dbumin] = 1.0 gldL; Canin~ .djusted [rCa""'] = 8.0 - 1.0 + 3.5 {± 1.3} = 10.5 ± 1.3 = 9.2 10 11.8 mgldL Im~rpreulion: If ch~ dog WlU not hYP""lbuminemic. its ,erum [ICa'1 would ~ from 9.2 10 11.8 mgldL in 95 % of conine sample•. Canin~

.djuslffl [rCa""'] =

m~~IUr..d

[ICo'+] - (004 X measurffl [TP]) + 3.3 {± I .6}

( 1I.Ib.)

Example: If [ICa'+] = 8.0 mgldL &: [TP] = 4.0 gldL; Canin~ .djusI. d [rCa""'] = 8.0 - {OA X 4.0} + 3.3 (± 1.6) = 9. 7 ± 1.6 = 8.1 10 11.3 mgldL Im~rpreulion: If ch~ dog WlU not hypoprol~inemic, iu ..,rum [rCa"'] would ~ from 8.1 10 11.3 mgldL in 95 % of conin~ ,ampl~. ,ulhors do not includ~ Ih~ "± 1.3," which i, ~n .S!imale of Ih~ 95 % of Ih~ publi,hffl dal .. b. The formul. ,hould ~ USffl coutiously for Ihrtt r=ns: ( I) Ih~ ~djuslffl [rCa""'] is .1 besl .n eslimate; (2) Ihe formul. v..as g~ner:l!ffl u,ing conine rCa""' and albumin con",mralions dff .. minffl by one..,1 of assays, and .n id~mic:d formul. would probably not ~ oblainM if olher :assays w..e used: .nd (3) Ihe formuJ. does not ronsider Ihe v:uialions in Colrption &om bone and incrra..,. Ca>+ absorption in the intmine, Renal excretion ofCa' + m.y ~ inc=std becau,. h~rcal"'mi. cau..,. an incrrasal filtered load (more filter+ mobili7.;,lion from bon~ or absorplion in immin~ Incr ... s excme excess dieta,y C .... Renal diseases that decr""" GFR impair renal excretion ofCa'"' and thut aouse or contribute to hypercal""mia." lowering dietary Cal+ intake by switching from alfalfa hay to gmt hay aon r..:!uce or diminat~ the hypercol""mia, but the impairal GFR l"",im." Alfalfa hay aon cont.in 2- 10 tim .. the Ca'"' ront~nt of gr:w or mix..:! hay." {2} Hypophosphatemia =y be p...~nt. {3} Ho,"", with hYl"rcal""mic renal f. ilure have a dec",as.d [iPTH]." b. Dogs . nd aolS with acute or chronic ",n. l dise... {I} Occasional docs .nd aolS with acute renal f.ilur~ are hYl"rcal""mic. Hyper_ cal""mi. m.y be du~ to an incr...... d ron""ntration of C." bound to citr.t~ or PO,. Rai.in .nd gr. pe toxicoses frequently result in hyperaol""mic .cute ",n.l failu",.'" {2} Of dogs with chronic renal f.ilur~, 10- 15 % are report":! to be hypercal""mic, which 'Pl"'" to be primarily du~ to binding of Ca>+ to retain":! anion •. " However, mon docs with chronic r~nal f. ilure have a low_normal to mildly deer.....:! [tC."]. Binding ofCa'"' to retain":! anions may also yield normocal""mia {[rCa'"'] WRI} that mad". decr""" in [£CaU]. 2. HYI""'drenocortici.m {Addison', dis"",,} in dOf:s .nd aots a. About 30 % of dogs with hypoadrenocorticism are hypercal""mic.' .... Hypercal_ ""mia has also been described in car. with hypoadrenorortici.m."-'-' Th~ r""son for the hYl"rcal""mia is not esrabli,hed but prob.obly is at le.. t partially aoused by decre;;osed renal excretion and might be aoused by increas.d C.'"' binding to protein or citr.te. b. Renal Ca'+ excretion in adrenalectomized dOf:s is dec ..as.d by excessi"" tubular reKlrption ofC? ... The reason for enhancM tubular resorption is not esub_ lished but m.y inml"" angiot~nsin II or corti",l deficiency. {I} When dogs with hypo. drenocorticism become hypovolemic beaou"" of mmiting, diarrh~a , or impair..:! renal con""ntming ability, angiot~nsin II a.ctivity inc ....... Angiotensin [] promotes Na+ r..orption in proxim. l renal tubul .. via a N.+-C.'"' rotransport 'Y't~m." Thus, enhancM resorption of

602

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY No.' may :d,o promo{~ th~ proximal rubular r~50rption of Co.>+ .lId cau.. hy""rcal",mia. Concurrent h.mocon~mra{ion ;t.df =1 ,lightly inc......., the ..,rum [rCa"]. {2} Administration of glucocorticoid. dot. inc...... tOruli excretion ofC,>+. Thu., • ddici.my in cortisol may allow more C,,'+ to ~ resorbd. 3. RupturM urinary bladd.r in foals: Th... foal. =1 d~dop hypercabmia (.uthors' unpubJishal data), but most do not. When pr... m, tho hyptrcalctmia i. probably cau~ by tho re;orption of urinary eo'+ from th. pu;rone:d Clvity. 4. Thi".id. diuretics: Th... :oct in the dinal lIq.hron to promote hypernatruria and, =ndarily, volu"", d.pl~jon. Hypovolemia promor.. . nhancnl proxim:d tubular resorption of No.+ and, =ndarily, proximal tubul" ,+." Thiazide:! abo promot< th. resorption of Ca ' + in Ih. diSl:d tubule •. " This form of hYP"rcole;.,mi. is rardy repona! in dom+ in proximal tubul ... 3. Junnil ... onset hypothyroidism:" Thi. may be COUIffl by inaUKd int.. tinat.bsorp_ tion .nd dec,..,asaI renal ncr.tion of c...>+. 4. A maina! fetus .nd endometritis in • doC" 5. Idiopathic hypc:rcohmia: This wa. found in a group of colS that did not have rerocnizc:d hypercale;.,mic disorders. Som~ of the cats had calcium oxalat~ urolithiasis."

IY.

Hypocale;.,mia (T.ble 11.3) A. H)'I'O"lbuminemic hypocale;.,mia (hypoproteinemic hypocalcemia)' l. Hypocalcemia r.. ulu from. decmued concentration of nogativdy charged proteins and therefore of protein_bound c, ... The regulation of the [1Ca"'] would be adequal< in th... animals unbs then: is a concurr~nt defect in th~ regulation of the [1Ca"]. 2 It has b..:n called p"udo-hyptJ€ilktm;a becausr the [K:."] does not decrease and clinical.ing ~meropathy in dog, Dietary vitamin D ddici~ncy (rare) Vitamin D- rcaptor d.f'""t rickets (viumin D-Jq>ra. thyroid suu and hypocal",mi .. Th. dy'!unction may be due to two proc....s: {I} Mg>+ 4+ on the parathyroid cdls and thus a lesser [1Ca""'] is able to inhibit PTH ""retion." b. The.. m.roanisms may explain the hypocalcemi+ binding and hJ'll"'C'1ctmia, or Ihe amrr nq>hrosis raluces Ih. tubular resorplion ofCa'"'. c. Olh~r concur",nt p.rhologic sUI~. Ihal Jruly be, contribuling 10 Ih. hJ'll"'C'lctmia includ~ .cul~ p.ncr"'lilis, ~thylene glycol poisoning, and hypoalbumin.mia. Phosphale en~mas a. In r~por!al fdin. =', author.; propos.d that th~ hypocalctmi. d.vdoped b"caus< of hyp'rphosphal~mia." b. Hypuphosph.remia may product hypoca.lctmia Ihrough Ihr.., processes: {I} Acmdy, Ihe high PO. load drives the following +.PO. romplnes deposit in {issues. b. PO, and lacm~ (producaj by hypoxic nroplmic cdl.) m"}' bind c,'+ in ",nal tubulu fluid and thu. inhibit tubulu resorption of C.l+ includ~ prouin., citrau, .nd PO,. 2. In this book, those .bb"",iations ar~ u.td: calcium ion (Cr+), frtt calcium ion (1Ca"), and total calcium ion (tC.lI - 20 "C.". c. [It:al+]: raising the pH deer .... s.. [fC:.'+], whereas low..ing the pH incr ....... [fC:.'+] .' The [It:a>+] changes by . bout S % for ....ch 0.1 change in pH. Exposing ",ra to air by simply in""rting tu~, containing sera and .ir low~ra! the [fC:.l+ Free: 4 Ca'"

pH = 7.5

Prol~ .,

bound: 6 C,.:'res th. effe.:. of the [l-I.] in plasma on the binding of Ca ' + to neg.tiy.,[y cb .~ pro",jn~ A similar efi'«1 oerun ..ith Mg'+. • At. pH of 704, thor. "'" Ca":ond H+ ions bound to pl .. m. or >dam {ddaya! effect} to rd ...", PO, from bon •. Becaus< of th~ pot~m phosph.turic action of PTH, th~ rd~= of PO, d",. not increa.. the [Pi] .. long .. "n.1 function it adeqUOning phosphat. in SI units of mmollL. 2. Rehtion,hip bttWO'tIl [POJ and [Pi] a. I rumo] of H,PO.- weighs 97 mg. [n I mmnl ofH,PO.- th ... are 31 rug of P. Th...fo .. , a solution of 97 mgldL ofH,PO,- comains 31 mgldL of P. b. I mmol of HPO,J.- w~iChs 96 mg. In I mmol ofHPO,>- th~ .. are 31 mg ofP. TIm. fo .. , a solution of96 mgldL of HPO,'"" contains 31 mgldL ofP. c. B~u .. of th. equilibrium among th~ diff~"'nt PO, mola;ules at a pH of 7.4, I mmol of PO, a""rages .bout 96.2 mgldL D. Unit con""",ion for [Pi]: mVdL X 0.3229 = mmoliL (S I unit, n..,..est 0.05 mmoIIL)"

[[I.

H~rphosphat~mia rr.bl~

1l.4} A. D«..~..ffl utinary PO, ac..-tion. l. Oisorde.. that d=rasr GFR {Itt p.. renal, rrnal, and postrenal :lWtrmias in Chapter 8}: Hyperphosph . tem;" oa:urs ba:ausc: PO, is not filtered oodeqlL>tdy from plmm.

Tablc 11.4. Oi"""".. and condition. that cause hrperphosphatcmia D=rasrd urinary PO, excrrtion 'Oa;",asal GFR {S«: pmenat ... nal, .nd post",nal azotemw in Ch ' pter 8} Urinary bladder rupture or urin~ I~akagc: into tissues Deem=' [PTH] or activity (hypoparathyroidisnt) Acromrgaly Inc",ased PO, absorption from intestine Phosphat~ ~nrm. or in~ion of phosphatr urinary acidifier Inc",asal vitamin 0 (S«: Tablr 1l.2) lochrmic intestinall.. ions (may~ also mift from ICF to ECF) Dirt with ~ low Cal+: PO, ratio (rarc) Shift of PO. from ICF to ECF Myopathies: endurance: rid., in horses, aertional rh. bdomyolysis, malignant h~rth..mi. Acut~ tumor Iy,is syndromr Other or unknown mechanisms Hypc:nhyroidism in em uctic . cidoois Hypc:roodrenorortici.m in dogs • A rel. tively common dioe.... or condition Noto: n,. [Pi ] in gro.. ing ID1ffim:d.s m. y I>. up to 3 mgldl bigher tb1tl Pi ",!'.ron", intrrvili for .dul", of tl>. sprci. In vitro hemolpis or d.e1' J"'d r+ is bound to anions such '" citrate and PO,. B. Mg>+ is loc;;otal in bon.. (about 60 %), in 10ft ti ....... (about 38 %), ~nd in th~ extracellular Huid. including blood (1 - 2 %). EJt""pt in C>ttl~, th. [tM g"] in erythro_ cytes is greater th. n in pla,m. (or ",rum). e. M.jor factors that det..min~ th....rum [tMg'1 I. Hypoproteinemia deer ...... the amount of bound Mg>+ and thu, may cau", hypo_ magnesemia (d«r..,...,d [tMg'+] ). 2. Ab,orption of Mg'+ in the gastrointestinal tract'O a. In ruminanu. Me is absorbed by the rum~n (and mayb.: intted into th~ .. rum from th~ .rythrocyres. In c;ml~, plum" and ~rythrocyte oonetion.

11 / CALCIUM, PHOSPHORUS, MAGNESIUM AND REGULATORY HORMONES

623

Table 11 .6. Di""ascs or conditions Ihal cause hypcrn.agncoemia D,""rrasM uri""ry exc"lion '(k",,1 f. ilure and other GlUst. of d,""",astd GFR Shift of fMg'+ from ICF 10 ECF Active in vivo hemolysi. Inc .... M [PTH ] Milk fever Inae"M intestinal absorption of Mg" wilhout incrrasM PTH or PTHrp MgO, Mg(O H)" or .imilar :mlacids or calhartics (catde) MgSO, (horses) Olher mechanisms Excess intrannous infusion of Me • A 1.t. .i""ly common dis< ... 01 condition Not. e. Excess uri nary excrgnesium ion {Mg'"'}, fr.., magnesium ion (fMe), and toral magnesium ion {tMg'"'}. In clinical jargon .nd in =ny veterinary publiatiom, fMg'+ i. often called i~niud ma~'ium and it abbrev:i. ated .., iMg, iMg'"', or just Mg'"', and thm there is a pot.ntial for mitoommuniation. B. Sample: Mo. • group, Ih. [fMg'+] in the dog. with uncomplicatal di.btu. mdliru, was much more v.ri.ble (.ome low and some high) Ih:m th. [fMg"] in the h""'thy dogs. IMMUNOREACTNE PARATHYROID HORMONE (iPTH) CONCENTRATION I.

Phpiologic process." A. PTH is. polypqltid. hormone (84 .mino acid.) produ=l by p.rathyroid gunds and inactivaud or dq;radffi by kidn~ .nd li~r. PTH is = ..Iffl by parathyroid gland, in respon .. to • danaMd [1Ca'"'] in blood, wh.rra, vil:omin D .nd an inc=std [ft:i'+] inhibit synthuis of PTH. l. PTH sa:,etion is priJrulrily mediated by £lor activity and hypocalctffi", or hyp+ mobiliution .nd d""",.. ~ plasma [Pi) by promoting phosphaturia.

[I.

Analytical oonctpu for iPTH assay. A. RIAs d.-vdopM for human PTH h:IV~ suflici~nt .p«i~, cross-r~.ctivity to b. valid fur domestic m:munab." l. iPTH v:dues g~n">IM by RIAl for intoct PTH or N_t .. min:d fragm~nt' rorrd>l~ wdl with a~M biologic PTH activity. Ba:aUst som~ immunoauays may r.... ct with preproparathyroid hormon~ . propa.. thyroid hormon~, intact PTH, or. PTH fragm~nt, th~ an:dyr~ of these .uays con rolJ""tivdy b. callM immunomutiw PTH (iPTH ). Only if th~ =y wa, 100 % .p«ific for intoct PTH v.ould [PTH) ~ual [iPTH). 2. iPTH ....,... t~nd to b.limitM to ~ndocrinology and larguble if the .ample remaim frozen during .torage or transit.'" In • subility study at 21 'C and 37 'C, the .strum [iPTH] remain.d nabl. for 2 d with two prot"'" inhibito", {Pefabloc SC and 4_[2-..minOHhyl]_berrz.ene=>ndary to decrnsed [ft:.""]}. B. Howt""r, many dog> with hyperra1cemia due to primary hyperpamhyroidism do not have.n increas.d [iPTH). Insttld, the [iPTH) is WRJ but inappropriatdy high in relation to an incr~ [fC,>+), thus reHecting a defecti"" neg.ti"" fttdbad: on PTH secretion C. In one study, many dogs with hyperadrenocorticiun had unexplain.d iner.. ",s in plasma [iPTH) and concurrent normoca1cemia.'"

IV.

Ckcrea..d """m or plasma [iPTH ) (Table 11.9) Table ll .8 . DiseUC5 or conditions that cau.. increased fir T H) Increas.d PTH production by naJplastic cdl. NaJplastic pamhyroid gland (primary hyperpamhyroidism) Multipl~ endocrine neoplasia (type I or 2A) Increased PTH production by hyperplastic par.lthyroid glands (idiopathic or >=>ndary hyperparathyroidism) 'Chronic ren.! dis ..... Diet with a low Co... : PO, ratio Hypocalcemic di",rd ... (with a decreas.d [fC,1+)), other than hypoparathyroidism Pstudo_hypoparathyroidism {decrrased PTH receptor re.pomivene ..} Hyper.drenocortici.m in dogs • A ,.ll1;""ly rommon di..... or ronditi"" Table 11.9. Diseas.. or conditions that cause decn:ued fir T H] Decreased PTH production due to damaged or removed parathyroid glands (hypoparathyroidism) Decrrased PTH production due to inhibition Hyperviuminosis D Hypercalcemic di",rde .. {with an inc ...... d [ft:a'+]} except primary hyperparathyroidism Hypom:ognesemia due to Mg" de ple"lion

628

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

PARATHYROID HORMONE-RElATED PROTEIN (PTHrp) CONCENTRATION I.

Phpiologic proa=. A. PTHrp promot~' C~lllcif.rol (vitamin D,). Vitamin D, can .1.0 bt of di """thyroid t..,,,,,,,,,,,"",,1atcd protdn roncopacti", ....tu.ti.on of 4J (1991r-2002). J Yrt I"""" Med 19.66J--6N.

DG. T.,...,..

do,.

634

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

59. Sd"..c1 PA. C ..... DJ. 2003. Drt..n.inatioD of calcium &",tionation in < 21 h ll92-139S. 9J. Vad,o SL li.e hn=PI•.,. pl"mnia, hypocok.mia and h~ io • cat . I Am kim Ho'l' A..oc n.J9.--.oII. 9';. Gucia_i.opni oyndrom, .uod"od .. id. ,,0.1 d,. pb.ti. io "'" ..... "'" ,,,,,;,tL j Y" [ot..;.", of ""P'ooium in ca .. wru. :Iir to limit th~ 10.. of ront~nU. B. [ncr~'!ffl ~nzym~ production by individual cdl. b=iu.e of induced .ynth~s.is l. This is th~ prim.,y mechanism for membrane enzymes and may ~. mechanism for mitochondrial .nd cytoplasmic enzymes. 2. buiucrion r~fe", to a nimulated incr~= in production of the enzyme protein via modifial transcription, tr:mdation, or othu processes. Endogenou •• ubnances (e.g., bile acids) or drug•• urn •• phenob.,bital, prednisolone. or prednisone m.y trigg~r induction. [ncr= in .. rum ALP activity r~SlIlt mostly &om induction (Fig. 12.3). C. Mor~ ~nzym~ produced by a ti!S\l~ b=iusr of ""U prolifer.tion, pmicularly for m~mb.. n~_'HOCiatal enzym .. l. NwpJ:..ia of the enzym~·s cdl of origin (e.g., increased ALP and B_ALP with o.tw ... rcoma, or increa!ffl LPS with pancreatic or extrapancre.tic nwplasia) 2. Hyperplasia of the enzyme'. ""II of origin (e.g., increa!ffl GGT with bile duct hYl"'rplasia, or increased B_ALP with bone growth or repair) 3. Convtrsdy, d~cr~.sed tissu~ mass may ~ associated with decreased .. rum enzyme activity or con""ntration (~.g., TU with p.ncreatic .trophy). D. Enzyme r~mov:ll from pI..,,,,, is decreased {enzyme has.n increased half_lif~}. l. Some enzym .. (e.g., A,\.lS and LPS) .,~ inactiv.ted or acr~tal by kidneys. Decreased r~nal blood flow l~.d. to d~cr~.sed ina.ctiv.tion of AMS .nd LPS.

121 ENZYMES

645

2. Some t< drivtional units, because .. bitrary uniu may b. ddined by mark«ily different ......y conditions. It is difficult to impossible to mnwrt the arbitrary units to internation.l uniu acruratdy. Fortunatdy, moJl current methods haw been defined in international units {UJ. 4. The international unit does not normalize methods. Different assays may measure different amounU of enzyme activity in the same sample. a. Because of v:uitions in some assay methods, enzyme .ctivities mrasu...d by two different assaY" may b. markedly different. Figure 1.5 ilJumate. the nwk..d differences that can b. found when one s.omple is analyzed by diff• ..,nt method •. Thus, aCetIrate interpretation of ... rum enzyme activity requires th at patient

121 ENZYMES

647

Table 12.3. Approximate changes in enzyme activities if Ihe .ame ,ample is analyzed al differenl assay lemperalures 25 ·C Common

~nzymes"

60-80 %

Rd.tin ~nzym~ ~ctivily al 30·C 32'C

"''''

110-125 %

37"C 130-210 %

• Including ALP. CK. lD. ID. ALT. and AST No..: Clunges :or«l on 'eported oon...."ion net""'.'" In 2002. th. In .. m. Oorul Fffits, l. Young dogs with musruiar dystrophy may h. "" marknlly increased .. rum CK activity (::> 500 X URL) and have mild to moder.t~ incrra= in ",rum ALT activity « 7 X URLj,l7 11 Som~ dystrophic docs occasionally hav~ extr~m~ AL T incrra= (values 20 times a. gr~at a. those in nond)"trophic docs in the same rolony), 2, Dymophin-deficient c;>ts with acute rh alxlomyol)"is had m. rko-dly incrra~ C K activity (89- 2000 X URL ) and incr~a..d ALT activity {6-19 X URL),"

652

V.

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY Spm~. diff~ .. nct' A. In dogs :md catiologic process~" oo""qm, :md facts: AST is a cytoplasmic and mitochondrial ~nzym~ th at catalyzes • r.ve",ibl~ rraction invalva! in the deamination of "'p.nau to form oxaloa=at~, which can ent~r the Kreb, cycle.

II.

Tissu~

III.

Analytical oonctpn: Oth~r than v.riations in .....y t~m~ratures, variations in .. rum AST activity ar~ minimal :mlong asiay syst~m. if ... ult, are rq>Ontd in UIL. How"""r, as for AL T, assay m.thods including the cofactor P·5·P may gc:n.rat. diff.",nt results from th""" lacking P·5·P.

IV.

IncreaKatocyt~ damal:" in dogs and cats. How.ver. it i. not as ti .. u~ specific a. ALT and thu, i, not a, valuabl~ di.gnostically. B=l.u.. canin~ AST is rq>Ortt studi.. indicate that incr~.sed .. rum GGT activity primarily dep"nds on the degr.., of hyp"rplasia of biliary epichdial ""lis .nd not on induction of GGT 'ynthesi', hepatocyte d:nn3.£ I yr old), the mnn CK activity WlU about 60 % ~a{" in the 6_ to 12_ ffio.oJd doC" 280 % g,ra,er in th. l _ to 6_mo-oJd puppies, and 410 % great" in puppie, less than I mo old." Also, th. me.n CK activity in small_brttd dog. « 10 kg) ~ about 70 % than activity in larg~breffi dog. (:> 25 kg}.'" Physiologic explanation, for th. "i:" and lxxIy.ju diff".nces w... not fuund.

gr..,.,

KlU'''''. of inc",asffi ",rum CK activity and CK half_life are li,rN in T .bl. 12.2.

[I.

Tissue

III.

Analytical oonctpu A. Orher than v.riation, a1~ by differences in :way I.m~r>rures, .. rum CK activily ha, minimal varialion among ''''''y 'Y'1~ms if ..",h. a.. rq"Jn«i in UIL The an. lytical r:m!';O' of som~ comm"cial =ys are 100 narrow for "'m~ domenic mammal" and Ihu, .... fr"'lu~ndy may nm to b. dilUl«iro oblain numeric resuh, when CK .ctivily i, incr~..«i, B, In .. mples from healthy dogs, Ihe CK activily in strum sampl.. i, about 2,5 lim.. thaI of pla,ma .. mples," Th~ diff~ren"" may b. c;mstd by Ih~ rd..... of CK from platdcts during clolting," conine pl'ld~u h""c b..n ..""rt«i to contain CK .ctivity," Thi, diff..en"" m.y not b. clinically rdevant when the incrn.. in CK aClivity is moderate to mark«!, Incomplff~ r~mov:d of plaldm from plasma could lrad ro mildly inc......d CK .ctivity, C. Canin~ CK a.clivity in pla,ma WlI5 nabl. for I wk at - 4'C .nd for I mo .1-20

-c,"

IV,

Inc=std .. rum CK aClivity (Tabl~ 12,S) A, A v.ri~ty of insults {pathologic and i.lrogtnic} may damage muscle fikrs .nd cou.. th~ rd...... ofCK from muscle fikrs, CK may k rde....d b«au.. of na:lOSi, or ..""nibl. ""II damage,

Tahle 12,8. Diso,den or conditio"" Ihal cause increased C K activity Musel. ~ (mosdy .kdel:d, ocauionally cardiac, r>rdy unooth) ·D"tgt. 2. From a .ingl~ insult (• .g .• recumbency or other traunu). there am bt vuy rapid inc= (hours) .nd a rapid dedine (hours to da,...) brcau", of the short C K half_life. B. Mild to mark~d inc=ses in serum CK .ctivity were .. ported in .no=tic cots with n ..oesoph3l:e. 1 tubt •.17 The exact p"thogtnesi. of the inc""ased activity is not known but prol>.obly involves muscle damag lOx URL}, b, In em with 'pontalla ",s paner~.titis, .. rum AMS .ctivities rang.. from WRl to mildly incr.,....! {< 3x URL},'· '-'" In a~rim~lIIal pancr~.titi. in six em, .. rum AMS activity did not illcr.... ~.'·, c. M~asur~melll of .. rum AMS activity has not """n u..ful for di"l:nosillg panc",_ atitis or other di ..as .. in hor... or ",nle. 3. P.ncr.,.tic lleoplasi call .lso I~:od to incr~...d .. rum AMS activity. B. D~iologic process.., concepts, .nd facts A. I'IIncrrilfic LPS is a cytoplasmic enzyme that r~qui ... Ca'+, coli!""", alld bile sal" as cofactor>. It "'taly= th~ hydrolysis of triglycerid ... Th~ panc"'.tic LPS mol«ul~

'"

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY (M, = 48,OOO) and colipo... ar~ ,maU ~nough to p .... through ch~ glomuular fihmion barrj~r 10 be, inactiv:nal or acretal. B. &v,,:d [ip"= .r~ in Ih~ body, and ~ach has sptcific roJ .. in lipid metabolism. Mor< inform.tion .bout lipid mlyu. Ih~ hydroly.is of stor«i TG .nd the libtmion of fatty acid.; it i, ,timulat~d by ~pinephrin~ and glucagon. 6. L}""Dmal aew IPS i, ~n intr:lcdlulor LPS that cotaly= th~ hydrolysi' of chol~u~rol ~u~ ... C. Compar«i to p... urgical m=urem~nu. ",rum LPS activity in four of fin dog. dec",as«i by 50-75 % by day 7 after panc=tectomy. Ho~r. LPS activity incr~= indiau«i that Ih~ p.ncr .... was a oontributor to .. rum lPS activity. but ther~ wer~ oth~r tissue source, in some dog.... Th~ nonpancreatic LPS in ",rum might"" gastric lPS or hepatic LPS. ar~

li,tM in T .bl~ 12.2.

II.

Tissue JOur"". of inc",= lOx URi}. b. In .pomaneous fdin~ p:mcreatitis • ..,rum LPS activity ranges from WRl to mod~ratdy incrmechason~ .ither at 2 mg/1q: or 0.2 mg/kg. In dog, with neurologic di",=. hyperlip"..,mia of incre~.ing ...... rity {mean value. 4.6x URi} ocrurr: em) .nd 54 % for caU with mild pancr.atiti, (eight mts),''' PU mrasur~m.nt' had mo", di:ognostic ",n,itivity th an did TU measur.menU or abdominal ultrasound.

12/ ENZYMES

669

OTHER SERUM ENZYMES M~ny ",rum ~nzym .. ru.v~ bttn ........d in an m~mpt to find btuor indialors of p.lhologic nale, involving hepatocyte, or olhor edl, (Table 12 .10). For a v .. ioplu.taoooph."'" i""",'Y""" in anin, .. rum. Y ... Oin r.thol20,51- 55. }6. SyoLlinu. M, Tili(>Kki M, Y.....d. I, H .... imotoA. 1m. Sq-atioa and q~nof I«tom,on pi ..... activiti. • .f ...yl.", iooamyla"" ~pa'" and oyptiD_tikr immwoo., .. ci';ty in """. R.. Y" Sci Sb78-l!2. 91 . Stidk JE. Cad_ WW. Boon GD. 1980. [......, ...... in dittkaIIy ~ do, •. Am J Y... R... "bS06-S09. 92. c.., .... M. Tp Mp>tocyte, rnd . n"'" tbe blood. it ern p ... tluougb tho glomerulu filtf1tion bartier . nd be """",,,,d in the urine. Beau.. Alb does not p'" tbrough the glomerulu filtr:otion buMr of most rrucnmrn. Bu/Alb doel not en"'r .... utine in thoo. . nimrn. BuiAlb. Bu :woci. ted .. itb 1lbumin: 11.1,. mocropluge: Sb. ''''rrobilinogSC\1]" hemolysis {= T .bl. 3. lOJ D«....«I Bu upuke by h.patocyw 'Fasting or anora"- (csp«ially in horses) 0«",,= [Be], it supportS the concept th at tho icterus is directly rdated to extravaKular hemoly.is. When dinirnl da'" indicate a hemolytic anemia .nd [Bu] < [Bc]. concurrent hq.atobiliry disease should be ronsidered. d. Oth.. expected laboratory findings with hemolytic icterus {I} Anemia, reCC'nerative if of sufficient duration, moderate to marked ","«ity {2} Hemoglobinuri and hemoglobinemia if the,. is mfficient intravaocular hemolysis {3} Bilirubinuria if sufficient Bc '''''pes from hrpatocyt .. or. with intravascular hemolysis, if thore is sufficient renaltubul .. home drgradation and bilirubin excretion into urine {4} [f pw.m. hopatic enzyme activities.re incre.=', hepatocyte dam,,!:, or cholest .. is rould be due to anemic hypoxia. 2. [nc..ased Bu production not :wociated with hemolysis a. Besid.. Bu from erythrocyte d.. truction. heme degradation also occur> with drnruction of erythr0C)1r precursors {ineffective erythropoiesi.} and degradation of other heme proteins (myoglobin, cyt:ochromes, .nd peroxid ....). b. By themselv.., these proce;ses arr not consid«ed to Gluse inc" ..ed [Bt]. HoW (AL T, AST, LD, [D, and GMD) may be inctused bemuse ofhepatocyt~ damage. chol~nasis, th~n

'88

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

Fig. n.l. Obstructin dtoLe.utic ict«;'" and ,h. ob.. rvds ex~".nct.

BILE ACID (BA) CONCENTRATION" I.

Phf'iologic process •• (Fig. 13.3) A. [n h~.hh, the enterohq>. tic circulation of bile acid, i, highly efficient, and llrarly.ll bile .aIlS excretrd in bile .'" return«i to the livrr vi. intestinal .bsorption .nd ponal blood flow.

Hepootocy\ll

..., \

PhJ"iologic procosses of bi!. . cids: ChoJ..ttin) involving hepatocyt~s callS< sufficient dallU&" to redu"" functional h'1"'tic IIUS.'l ~nough to impair BA de"an""."''''' b. Congtnital . nd acquired ponosy"emic ,hunts ~nabl. bile ..Its . b",rbed in the intenine to bypass the liver. =pt the enterohep>tic circulation. and ~nter the systemic blood."" c. Mild inc",a.-;.. in [BA] may occur when f=:l is withhdd from hors ..." The incr.... is prob.bly caused by. d=.....d hepatic dtlran"" rate of bile acids! 2. O,""",ased biliary BA excretion a. A variery of hep~tic and "",thepatic disorders can imp.ir bile flow and thus impair acretion of bile acids. Concurrent impairment of &: acretion is apected. but it m.y not be enough to cause hyperbilirubinemia. Similarly. when hepatic or ""nhepatic hyperbilirubinemia is p....,nt. increastd ",rum [BA] i. apected. b. Ouring obstructi"" choleswi •• th«~ is a down_regulation of caruolicular BA transport proteins. and hepatocyt.. may pump BA into sinu",idal blood insttld of into canaliculi. This process may aplain the "regur-gitotion" oon""pt of BA l.... ving hepatocyt ..." c. BAI are toxic to cdh. Thus. accumulotion of BAs in the liver may l... d to cdl dam"1:e .nd rel...... of BAs and other subst.n"". from canaliculi . nd hepatocytes. d. Cytokines {notobly tumor necrosis f. ctor alpha} have b«n shown to dec ...... BA transport proteins in hepatocyte canaliculor membranes .nd thus impair BA s,""retion.""" The /"1' E. In cattle. the diagnostic sensitivity of .. rum [BA] varied .mong liver disorders: f.scioliasis {I 00 'Job. n = II I. biliary calculi (100 % . n = 2). hepatic . bscesses (53 % . n = 15). leptospirosis {71 'Job. n = 7}. and hepatic lipid""is (86 'Job. n = 36) {",feren"" interval not stoted but upptr limit estimated from a graph to be 40 J.lmolfL)."ln another rq>On. values for .. rum [BA] wtre incr.....d in cattle with hepatic lipidosis. hep>tic absc.:lRS.leptospirosis •• nd foucioliasi, with mean con""ntrations of 90--225 J.lmolfL at initial evaluation." IV.

Bile ""id challengt ten for dogs and cats A. Principle: A 12 h f"'ting [BA] provid.. a baseline assessment of the .mount of BA that escapes the enterohepatic circulation .nd ente" the .y.temic blood. After ingestion of. standardized meal. g.Jlblodder contraction release. bile ..Its to the intmine. from which they are ab"'rbed :md then em« the ""nal blood. Thi, influx of endogtnous bile ""id, challenges the . bility of the hep>tocytes to keq> bile acid, within the emerohepatic circulation.

694

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

Table 13.8. Re:.u1u of the bUe add challenge

l eU

in dog"

P~r< n:d»orW os port of:m ..,terob.". tic cirrul1tion (:tIso ... Fig. 8.5). • Rerul """ecion of NH: moy occur by NH; passing through th. glomeruhr filt",ion barri.r:and oong """,.ted in the u.m.. NI-V is:olso fixed into UfO' in tho Mpatocyte> or into g1uumine (GIn) in tho «an tubulll cello. [n '''pons< to .cidemia, deomin1tion of GIn to g1u'1JJUt. (Glu) in the r.,w tubule. , ....1" in NI-V =''';00 (_ Fig. 9.6). • NH: it the moktions of N_aatyl g1utaJrult~. A d,""reasnl N_acrtyl gluum>le con""ntr:ltion couses d,""reasnl .ctivity of corbamoyl phosph at~ symhdulu. The pathogenesis of th~ hyperammonemia in th • .., pups was not d.t~rmined. but Irish "..olfhounds do h"". a high inciden"", of ponosY"'temic shunts." 5. In 69 dogs with hepatic encephalopathy causM by ...."al linr di ....s.. {including 14 congtnital .nd 29 acquirM munts}. th~ [NH.1 in art~rial plas/rul . nr:agtd 1.5 tim~s the [NHtioIlS ~. be lower ba::.use of enhanud NH.t cl~...n"" from . mri. l blood by kidnqt~. NH, that com_ bines with H+ to form NH'. This ""h. ruminal fluid mo", alkalin •. Wh~n th. rum~n pH i.;> 8.0. the NH,:NH.+ ratio mift. toward NH ,. which diHU .... from th. rum~n to plasm •• whe .. it combin~. with H+ to inc",as1ffiplr is oonsi".nt .. i,b • pon",y"rmic sbunt Of h«n' .. 'iono of gluooo ocids. G1uagon _ ...ion is "imul...d by i~ blood . used for m... suring blood [g1uco..]. ~ral are d..ignal for u"" by JlO'pl~ who a.. monitoring th~ control of th.ir dial>.tic l1at... Th~ instrumenu typically will provid~ useful resulu if th~ unit is ol"'tating corr«:tly, if the sample i. colla:tal prol"'rly, and if manuf.cturer', dir«tion. ar~ follow.d pr«i.dy. 4. [Glu=] in arterial or mpillary blood i. gr ... t~r than in nnou. blood b.a"", I"'ripheral tissue! mnrum~ glUCOst. Th~ diffe",nu in normogl"""mic and normoin_ SlIlin~mic .tat.. is probably < to mgldL C. Wh . t i. m... su=i: whol~ blood or pl:asrruo [glu=]? l. Wh~n .n assay u ... whol~ blood for a sample, it i. important to know wheth~r th~ result r~pr=nt. a whole blood [glucost]' a pla.ma [g1ucose:]. or. calculatal pla.ma [g1uco..]. Som~ instrumenu m~amre and report whole blood [glurosr]. Other inmum~nts m~.. u",. whol~ blood [glum.~] .nd calculat~ a pl:asma [glum ..]. Of th ..~, some . ..mm. a normal Hct valu~, and thll'l the calculatal value will not I>. corr«t in an~mic or ~rythrocytotic sampl... " Som~ whole blood =Y' me.. ure molality and not molarity, .nd thus variations in th~ H,O content of blood (~.g., du~ to di.pla""m~nt of H,O by protein. or lipid.) will influen"" m~.. ural [glum..]. '"'' Th~ .. han btt:n ..nral reports of comparison. of [glUcost] m.:asu=i by differ~nt blood g1uw.. instrument. or :assays. Som~ of th= nudi...'" difficult to int~rpret b.aUst the types of [g1uco..] (i.~., blood, pl:asma, or strum) w~re not sp«ifial and diff~ren= due to differ~nt Hct valu.. w~ .. not consid~r.d. 2. Whole blood vc:rsu. pl:asma or se:rum [glumse] a. Glucose i. uniformly dinribut~d in H,O component. of whol~ blood (glucose: frec:ly diffu ... I>.twec:n pl"'ma and ~rythrocytes), but the .. are . bout 71 mL of

Fig. 14. 1. «m,;nwa o Muod.: Gluros< upuk. by myocyte< i.s promot«l by inru~n tltrough 'f'lis (,.m~ concq'" as with .,"reme leukocytosis): A la>kocyt~ need. more gluco,. than an ~rythrocyu, but typically th~re.re .bout 1000 times as many erythrocytes •• leukocyt ... Markal rubricytosis would .1.0 prob.bly cause increase-d gluco,", consumption." F- or

bromid~;

~iviIll:

Ill.

HYP"rgly""m", A. As in summarized in th~ preceding Physiologic Proa:s.ses section. pl"'ma [glucose] is influencnl by many factors, so it should not bt surprising that ther•• re many couse. of hyp"rglJ'C"mia. I. Th~ ddinitions, diagnostic criteri., .nd clas..ifications of DM uK with acul< mcubolic d 250 mg/ 150 mg/ tioncreaticj OM: acromegaly, glucagonoma, hy~rad .. noconicism, hyprism, hyp ha"" .nti-IJ-a:ll antibodies," b, Ty~ 2 OM {inmlin resinan", with inadequat~ rompcns>tory insulin secretory re.pofl5C:}; previoudy callM non--insulin-d.".nd~nt OM, typ< 11 OM, or .dult_ on.. t OM {I} Thi. JOrm of OM i. mon common in c;ots .nd i. c;ousffl by d. fca. in inmlin secretion .nd poninsulin =cptor defecl. in target cd]', th~ two major crit~ria for ty~ 2 OM,'"

716

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY {2} [n em, ""id~n"'" indicau. that .mylin (amyloid polypttll colled diabetic dermatopathy, n=olytic migmory erythema, and SIl~rficial n..:rolytic d.. matitis. The pathogtne;is of the hyptrglJ=mia is not e:sublished but /ruIy illvol"" illsulin ruiJlallct, glucagon. GH. or alterations ill amillo acid, fatty acid, or rille meuboli,m. It ap~ar:s ,hat the di.betic .Ute devd0p' after th. O"""t of hepati, dist.... , but it has not }"'t i>ttll esublished if th. li""r di",.... caustS the diabe.tic state. (3) Drug_induced OM: ~"istem hyptrglJ=mia (2 or more dap) associated with u .. of. drug (a) Sr.roid. (glucocorticoids) (Stt GluC0.!e Cona:mratioll in Serum, ""'. 1I1.B.l.c) (b) Thytoid hormones: Studies ill cats.uggest that hyptnhyroidism creates a nate of ill.ulill res.inalletocytes, myocytes, :md adipocytes .nd decr~ased gluCSt production by hepatocytes, Inmlinomas may cous:p«t":! to b. marketUy und."""ight or em.ciat.d. d. D=ra,..:! glyoo~noly.is: Cong.nital ddici.ncie, of .nzymes nttd.d for glycoge_ nolysis may contribute to hypoglJ'C'mi •• nd accumulation of glycog..n in cd], {glycogcific ,ozyrnat;" d.f= w:as not .,ublish«l. Th. dogs did nol han malonyJ~nzym. A (CoA) d=rboxyl= ddi_ ci.ney .... Da:,rasffi gluconwg.n .. is probably rontributrd to lh. hypoglyami.>, kcau .. incrrasN [nulonyl_CoA] inhibits pyruvatt cuboxyla.., :m aic animal may c;m,, , hypoglycrmia b«:au.. of th. = utilization of g1UOOR .nd deere=gents in .. rum could cause fal .. _positive remits. In rontr>Sl. th~ fructosyl lY'in~ oxid= =y is conlid~rffl to ~ specifie for fructosyllysine. a .pecific glycatal amino aeid. a. In a romparison study. th~ fructosamin~ ronctntrations in conin~ .... d~er_ minal by th~ nitroblue tetrarolium . ....y wer~ .bout 3-4 times thou d~t~rminal by th~ ~nzyJrultic =y {about 100 J.l moUL}.'·' This study rai.es • conctrn about the validity of the [fructOiamin~] .. ponal from th~ nitroblu~ utrazolium assay. b. Modificotionl of th~ nitroblu~ tetrarolium :assay to ",mo,,", actions of rfflucing sUNtan= other th . n fructosamin~ rqrortally ..suited in [fructosamin~] of . bout 10 % that of the origin:'! nitroblue tetrarolium .ssays. '«l 2. Wh~n mu.ural by .pectrophotometric ......Y'. hemolyzed and icteric .amples can cau", e"on""us remits. B. Glycatal Hgb conctnt ration! or per""ntage'l l. Glyaual Hgb has bttn m~mral by chroIlliltographic. immunoturbidimetric, and chemicol ..... ys. ~ch with its own limiutions. Some ...... ys w~ .. d.. ignal to specifically det«1 hUIlliln hemoglobin A,cO wh~",... oth~", {e.g.. chemicol methods} det"'t multiple forms of glycatal Hgb. 2. Results.", um:.!ly reportal as th~ per""nt"l:~ of tot:'! Hgb th. t is glyaual. 3. If lipemi is p.... nt. the a.... y should ~ rompletal after washing the erythrocytes; lipemia wiU f. hely inc",...., perctnug.. in some .... ys.' ... 4. Th~", w;o. good agr..,ment ~tw..,n • rolorimetric =y .nd • chrom. tographic method with canine blood.'" 5. An immunoturbidim~rie manuf. ctural for m~a.!uring hUIlliln [glycotal Hgb]. has bttn u=i to m=ur~ canine [glycotal Hgb] ...·'..

.t.U)'.

Ill.

Inc==! [fructosamine] and incr~ glyaual hemoglobin perctntage or con""mration (Table 14.6) A. Di.~tes mellitus: Inc",=uboli,m of albumin is d«""a=!, 50 it, half_life is incr~~.ffl. Thi. ",suIts in g... t~r glyation p"r mole of albumin. thus romewh.t counuracting th~ decruK in fructo.iologic proc:=e. A. Insulin i•• polypnd",d =y for eonin~ IRG wa •• radioimmuno:lS""y with Ung~r's 30K antibody, all antibody that W:lS colI,id.red .ptcific for th~ C t~rminu. of glucagon.'" Oth.. investigators h:IV~ .hown varying dog .... of antibody sp«ificity for pancr .... tic glucagon and glucagoll_lih immunor~activity."" 2. One group of in=tigato.. d..crib.d validation ,tudi.. ming .n anti_{bovin. glUSting lIat~, .bout 30 % of the glucagon_lik~ immunor....ctivity w;u pancr~atic glU lO_fold ill ""m~ pla.ma ... mpl.,} ill • ",... nillg Muation. ,.. C. Samplel I. Mon investig.to.. colISid~r IRG to b. v~ty unstabl~ in blood, .nd thu •• ptcial handling i. =mmended." [mm.diatdy aft .. collr,tl9- IH. 10. o..; ..opb", M.\1. O'N,iIl S. 2000. E./foct of op. R.. V Iic inHamm.lion . '" not Ihoroughly und~mood, it i. known Ih . 1 p.ncr .... lic acinar cdl d.magt i. a mojor roll5~u~n"" of Ih~ inHammalion. B. [n .cut~ p:mcrntiti, (from mild td~m'IOU' to ~ .. n,""rolizing or h~mollh"1:ic) , Ih~ rd~",~ of cytoplasmic ~nzymes from th~ dam>gffi :>cinar ",n r~sull in inc=d ..,rum aClivilies of AMS :md LPS (..,. Chapl~r 12), incmutd .. rum [l1l] and [PU ] (Ott Chapler (2), and increas.d urin~ and plasma [TAP] (... Trypsinogtn Acliv' lion Pq.tide (TAP) in Dogs, 5tCL IIl.A). Among domOSlic mammal" .cul~ p. ncr .... litis is mon common in dogs. Alfecttd dog, frequ~ntly h. ve an .cul~ onsol of clini",l sign, ,uch .. .umiling and .nurior .bdominal pain. e. Chronic p:mc",alili, may resull from ra::t1r",nt ~pisodes of acule p>nc",alili, 01 slowly progressive destruction of pancre.lic acinar ""II.. Wh~n """..~ . the p:mc",.. may not bo able to ,,",,ret. ,ufficient ~nzym .. 10 digest food, .nd Ihe animal may devdop EPl. Chronic p:mc",alili, occurs in alU and I.".. commonly in dog" and moy ... uh in EP[ wilh clinical ,ign. mch .. progressive weight loss :md soft or malformw f=,. Endocrin~ p. ner .... li, d,..filllction moy .lso .ri..,.

""U,

Ill.

[ntoninal mal.bsorplion A. Sevoral .mall intestinal d~, "'.... inad"luate absorplion of nutrient' .nd thu, inteslinal malabsorption. Th. nuL.bwrptive nale amid bo locali=:l {e.g., proximal ,m.ll intenin~ 01 il~umJ or diffust.-. il oould involve malabwrption of mony nutrient' (e.g., .ugars, proteins, .nd f. I,) or bo very specific (e.g., cobalamin). When intestinal malabwrption i. not ",,"u,ed by. specific absorption d~fect, the .nimal i. prestnted beau.. of w.ighl loss 01 malformtd f'""t>. Acule enteric di ......... lhal ",use diallhu for a few daY' prob.bly ""lISt. I~mporary mal. bwrptive nale, but .uch disorders .'" not Iypi",lly ron,idorw in discussioll5 of mal. bwrptive disord~" beau.. Ihe .. i, not • concurr~nt malnouti.hed ,Ule. B. Intestinal di ......., lhal l~ad 10 mal.b,orplion occur in mo,1 .nim.l species, but laboralory tests are u.td mo,tly to Ih. URL, Th. authors SUggt'lIW Ihat Ih. [TLI] was inc=d ba::au.. of toxic df=, of dcxamethason~ on Ih~ ""nct.as," c, C.U

{I} [n. pro,pecti", nudy involving 28 cats with clinical 'igns rompalibl. with panc""atiti" the .. v.. .. nol .ncreatic tissue ...spcctivdy. by th. investig.tors. 3. Refc:r~nce interval, vary wilh the mffhods usal and .mong laboralories. C. Sampl~ ~rum is Ihe p ..ferrM .. mple.

111.

Incr.-..M [p>ncrralic lip... immunorraClivityl [PUI (Table I 5.2) A. [nc... ...:1 rd~ from damagnl ""ncreatic acinar cells l. During ",!",rimental and spontaneou, p:mc ....uiti •• LPS i. rd.-..M from damagM panc'"". tic acinar crll. and ~nters th~ blood (probably via lymphatic ""...ls). 2. PLI te,ting has the . dVlUltagt over moll routine .. rum LPS assay, of king specific for ""ncrcatic lip .... and testing i, OffcrM by some la,!:" '~terinary ..fcrrallaborato_ nes. How~~r. rcsu!ts may k too delayed to be u..ful for diagnO!ing and managing patient, with acut. pancreatiti ..

".

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY 3. Dog" Wh~1I d""j,ion th ...hold, of th~ URL or of.n ~mpjrical ...Ju~ g=t~r than the URL w~re u~, the [Pll] had a di.gnonic .. mitivity for acut. pancreoltitis of]oo % and 82 % , re'Jl"Ctive/y. " Diagnonic ..,nsitivities of LPS and TU were

I.... 4. Can: Th. [PLI] (with dros.ion thro;hold of 10 IlgIL) j. ,.portal to han ~{{.r di"i:"o,[ic stnsitiviry for P>flC'''''{;lj, than d"". the [I1.I] in cats." Aft,r uperirnen_ tal initi.tion of p"ncrratitj. in mIS, the [PUl had g,rater incr= {SOx basdine '" 35x baseline} .nd more penistem increases (IO d vs 3 d) than did th. [TU].'" B. D«r••.ffl renal drannc;., in disorders chat au .. da:,rasnj GFR l. The kidneys at. involvffl in the ,.mov:.! of pancr",,{ic LPS from plasm. {= Chapt.r 12}. When th ... are disordm that muh in d,"""asM blood flow through th. kidn"Y' (i.•.• p",.."al, .. nat or posIten:'! disorders), th~n LPS h... a 101lg~r circulating h.lf_lif~ alld thu. COli accumular. ill plasma. 2. Usillg the collin~ PU ELISA. the [PU] was mildly illc",asal ill dog. with aperi_ m~mally illdu=:! chronic renal f.ilur~. but 1I0t above th. suggested diagnostic threshold for p""u... titis. "." Lock of illcr .... ed .. rum lPS activity in this srudy suggests that the modd =y not have bn,1I .ppropriate for ...... illg changes ill [PLI] cousal by rellal failure.

[v.

Decrnsal [p""creatic lip"'" immunoreactivity] [PU] [Table IS.3} A. Rd.... e of LPS from p,"creatic acinar cells may k dec",... ed ill disorden associated with redu=:! functional p"nc ....tic aci""r tissue. :md ther.fore .. rum p,"creatic li~ immulloreactivity oollcemmiollS =y k decreasal. The primaty disorders ill dog. and cots .'" chrollic p,"creatitis (which l... d. to destructioll of most aci""r cdls) and, ill dogs. p:mc",atic acillar .trophy (an immune-mediated disorder of ~rman shepherd. and rough-coated collies). B. [n. study usillg an ELISA. .1125 dogs with EP[ (... d.fined by havillg a decreasal [TLI]) had decreasal [PU]." However, TIl i. prefer=' over PLI for diagnosis ofEP[ kc.u .. TLI .ppe.n to differ.miat~ affected dogs from healthy dogs more d ... rly, and it may have ~.ter diagllostic .. nsitivity for EPI.

TRYPSINOGEN ACTIVATION PEPTIDE (TAP) [N DOGS

I.

Phy>iologic processe" After ingestioll of. meal, ttypsillogell from p"ncreatic aci""r "",Us emers the intestillal lum," :md is de.ved by the .ctioll of enterokinase to produce trypsill and TAP,." ~ight"""mino-a.cid N_termirud deavage peptide. [n theory, the TAP is not absorbed and thus d~ not ~nt.. pl ... m• . A millut. [TAP] con k foulld ill plasma .lId urine of healthy dogs, p remmably from .ctivation withill the p:mer......"

[I.

Analytical oollap" A. Ulli" l. Plasma: nmollL 2 Urille: nmollL; also ..""ned as • TAP: Crt ratio B. AssaY': An immuno......y (either enzyme immun1hw~y>l involving folate {Fig. 15.2).'" B. Con..lamin i, also a r«iuired cofactor fur th~ convtrsion of methyl malonyl eo e"aly= tb. oo.",,,,ioa of N' _methylt .. riliydrofoht. (tb. primory molecul. in pJ.UJl1) to "'trahydrofoI.",. which i, tbea avail""J. for D NA .ynth"'i' in ",,]k If tb... is • cobol. mia ddiciemy. tb. methyl group of N' _methyl«tuhydrofoht. i.s not trrnd'erred to cobalamin ("",thyl trapped). :ond thWl • ""llul., deoei=ld~ Preabsorptin d~fecl in doc' and cm £PI: pancre>tic atrophy, chronic panc'''''litis Intestinal oocc"i;d o,,",rgrowth: EPI, impaired emrie acid stCrelion, em,,;c di,ordw; (Stt the text) Dd'r and caU 'Ileal di~ inflmunation, I=;on, villous atrophy (viral, hy~mnsitivity, cytotoxic drug.) Coo/:"nirai ddicicncy of r~{or in giant Khna~rs and Border colli." ~ve"" cobalamin ddicicncy in a cat (probable congtnitod malabsorption d.f= ) • A rel.tively common dioe .... 01 condition Noto: lins of .prted to low.. [foute] in Jl"OPl~, but similar findings have not bttn r~ported for dogs or cats." 3. In thwry, st~rilization of the int.. tin~ with . ntibiotics may low~r .. rum [folat~] beca"", a major source of folate {int.. tinal floral would bt removed. Also, fol . ", is involved in DNA synth.. is, 10 """,nsin neoplastic ""J] growth could potentially deplete fol.te levd,.

15 / EXOCRINE PANCREAS AND INTEST INE

753

FECAL CI.,_PROTEASE INHIB1TOR (CI.,_P1) CONCENTRATIO N 1N DOGS AND CATS

1.

Phy,iologic process.. A. u,.PI is a protein th~t inhibits the activity of prote=. (e.g .• trypsin) in fan. It is "port.d to han n.-arly the same mola::uJ.r m.., ., albumin. CI., _PI is normally p""'nt in plasma. inte"titial fluid • • nd lymph but not in the im.. tinal lumen." B. The a a.ct identity of this protein has not bttn found. B=UK it i, considered to b. of blood (plasma) origin. the antiproteaK a.ctivity may b. due to u, -.mtitrypsin {humm M. = 54.000} or CI., _antichymotryp,in {hum.n M. = 68.000}. The "porta! mola:ul.. m.., of dom.,tic mammal u,-PI mol«:llies v",i.. .lightly with the species: canine M. = 59.000. feline M. = 57.000. and equine M. = 58.000."

11.

AnalyticaJ concepts A. Units: llg/g of feces B. Sample l. Becau.. of the VlU"'tions in [CI.,_PI] fecal "'mples. thr.. q>:Irate void.d fecal sampl.. are colla:t.d. Colla:tion of feces by digital ot ma:MnicaJ .. moval of fan m. y introdu"" blood into the sample. which will =ult in falsely incre",.d [CI. ,_PI ]." 2. After collection. the fecal "'mpl.. should b. imm.diatdy frozen and shipped with dry i"" to the "feren"" loboratory. When L:.pt at 37°C for 72 h. the [CI.,_PI] da:r.-aonl by . bout 30 % : when k.pt at 4 °C fot 72 h. the concemmion da:r.-aonl about 5 %."' C. Currently. ther. is one ELISA for measuring immuno"acrivity for [CI. ,_PI ] at Texas A&M·, G"'irointestinalLabomory (Colleg. Station. TX}."' D. An =y for fdin. [CI.,_P1] in .. rum Ju. bttn d~loped. but docum.nt.d evidence of clinical application wa.! not found."

111.

Incr.....:! f=l [CI.,_PI ] A. 1nc... ..d plasma protein loss into intestin.. I. Protein_losi"l: enteropathi.. cauonl by ate",i"" intestinal disease such as lymph.ngiect",",. idiop>thic inflamm. tory bowel di ....... {including lymphocytic, pwmacytic. or eosinophilic disorde,,}. intminallymphoma. int.. tinal carcinoma. hi"",,viral enteritis.'~"

2. Blood loss into the alimenury trace: Blood loss may b. :woci.ta! with protein_ losing ent.rop>thi.. (•. g.• ulceration ot cminoma). but it may .lso b. due to hemorrh"J: A. D-Xy{"u is •• jmpJ~ ~nto .. thai j, not commonly ingm""', and nry li{d~ is pr...,m in blood or livtr. If ingesta!. jt is p:wivdy absorb«! in th~ duod~num and proximal j~junum, from which it ~nt~'" porru blood. Aft~r byp:wiJll: th" lin•. it p"'" through the glomerular fi]tr:uion barr;" and is aa~M in urin • . B. In pn>pl., xyJos.. Ih. glucuronic :ocid- xylulo .. pathway in h.p"[ocyt ... It i, oma/ly :assumM that "''1 liul. of Ih. absorb«! xy]"'" i. dq:rad..d by hq>.tocyt~ of domestic m:omm. b.

.nt."

[I.

Analytical oonctpu A. Unit 0011"""';011: mgldL X 0.06661 = mmolfL (SI unit, nr. rest 0.1 mmoUL)" B. A..ays I. MllhipJ. xyl= =ys are .vail.bl., but clinicalloboratori.. do not commonly off., thrm. 2. A oo]orimthologic

isolat~ (~.g.,

.tu~

Bact~ri.l ~nuritis

s..lmonr/Ia sp. ) Bact~rial cuhur~

(qu . mitati",)

Biopsy procedures {incision or acision}

10' colony.forming units/ mL of duod~nal JUI"" Abnormal edl popuJ.tions or abnormaltissu~ ;>

S!ructur~

Motil~

Dirrct f.-cal H . m F.-cal flotation test

!",rasit.. Parasitic ova, ooc)'l~" or

SmaU intestinal bact..ial onrgrowth V ..ies with th~ hi!lologic lesion; rypica.lly inflammation or neapl"'ibo.l.",in tuppktn=tati.on in "'" ..ith ti&no of """,,""nirutJ dioc.. .. and ..... '" b~amin"";" ) Y" [.. """ Mod 19,I S5-160. 22. M,,,atoc)'i'" and ~m~rocyt ... O. Wh~n lipoprot~im conl:lining .polipoprol~in C-11 bind 10 LPL on endolhdial "",lh. fmy acids .. ~ cl~'vN from TG mol,""ul", and ~nUr cdl, {e.g.• adipocyus .nd myo_ cyt"'}. With .. ~ated proces'ing. th~ lipoproteins krom~ TG d~plt ronlain chylomicron, do not have a detectable lipid lay~r.

References

IJ. 1999. Lipid •• ~P"P""'tt-. hl odition. 8.J-II S. s.., Acad.mic. G..,.. Kt.. WcddoiDd KJ. CowdJ CS. Sdoonob ... WD. Jnvdl DE.. Zki .. SC. Dd>c...kd", J. F...,. RA. 2000. N."","". [0' H...d MS. notd." CD. Rrmilt..d RL. ~ P. cd •. S-Ilkm../Cs..;,,J N"",·';"' . 4d. cdition. 21_ 107. T opeb.. KS, Mad. Mo .... Inrtituttions, . hypothyroid kitt.n may have [tT,] within the .dult ",frrenel)."

792

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY {3} Lock of TSH ',",,"'Iioll caus.. atrophy of thyroidal follicular cdb and thus drc,,,,,sal T. and T, production. c. T~r{",ry hypothyroidi.m {caUoN by TRH ddiciency} (on. form of umral hypothyroidism): Th. alImO," are not awn, of documemM cas •• in domestic mammals.

d. D.f«tin T. production {I} In dog., iodin. org.nification d.fecr'" or roDl:"niral thyroid p,",oxidase drficiency in toy fox urri",;"" {2} [n foal" iodin. ddici.ncy from drctrasN dietary incako {fool :md dam}" {3} D.frctin thyroglobulin synth .. is in M ..ino ,h, Dutch goats, .nd mj"", prod"""d hypothyroidism. How"""., d.frctive thyroglobulin synthesis in

Afribn.r (Afrikand,,) cattl. and Bongo .ntdo"" produaJ euthyroid con~nital goit"';'" 2. Multifactori.l {may include d.crUsffl T. production} or unknown ma:runisms a. Nonthyroidal disrases {I} '\hny infLommatory, neoplastic, metabolic (e.g. , rrnal f. ilurr), and endocrine di",rde", {.. p«ially hy~radrrnoconicisml a", known to d",,,,= [tT..]. Sick euthyroidism {ru from Grttk, meaning · w.U"} is th. condition in which a di,.a", outside of the thyroid hormonal .ynem cr•• t.. hypothyrox.mia. {2} Nonthyroidal di,....ses =y lo~r [tT..] by on. or mo .. of the following processe" (a) O«rra..ffl protein_bound T. beau.. of d"'r~ concentration or affinity of binding proteins {b} Inhibition ofTSH ''''rHion (c) Inhibition ofT. production {2} Ass=ment ofTSH and [IT.] .. =y hdp diff... nt iat. nonthyroidal illness from hypothyroidism when [tT..] is d",,,,....:! in dog. with clinicol signs of hypothyroidism. b. Many drug> (esp«ially glucocorticoi.u) a", known to low.. [tT.] . {I} Dog. with hy~radrenoronicism f=iu.ntly h. vt decreased [tT..]," but changes in [tT.] in dogs receiving glucoconicoid th.rapy a.. variable. Th. [tT..] did not changt in one study,'" wh .....s the [tT.] dec",....:! in .noth.. study.' Th... is evidence that the changes in [tT.] are COU..ffl by multiple f. cton, induding reduced TSH KCrHion," and th at the thyroid gl and. are Ie .. responsivt to TSH." Th..e i, also evid.nce th at glucocorticoid. reduce the oonvtrsion ofT. to T , in ~riph.ral tissues." [ncr~ [TSH] is not ap«tni {2} [n dog., prednisolone,' trim.thoprim_sulfadiazin. ," trimethoprim_ sulfamethoxazol.," and phenobarbiuP'" treatm.nts havt bttn shown to couse hypothyrox.mia. Sulfonamides int.rf... with the iodination of thyroid hormones by inhibiting thyroid ~roxidast- activity,'''' so [TSH] =y bt incr ... sed. {3} [n horses, phenylbutazone and glucoconiooid trratments ru.vt b..n shown to cou.. hypothyroxemia." {4} Clomipramine (ClomiCalm) administered to dog> for n... rly 4 mo d",rr....:! [tT..] and [IT..] ... Th. dec ...... in [tT.] was detectable .ft.. I mo of treat_ m.m, penisted for the duration of the aperiment, but did not drop bdow

17 1THYROID FUNCTION

793

the low.. r,f... nce limit." Clomipnmin. is usa! for. v. ri"y of bdt. vioral disord .... c. Th. following h.ve bttn mown to produce low.. [tTJ in horses: (I) Diets high in . nergy, protein. copp'r, or rinc {2} Ingestion of endophyt._inf«1ed f.",ue grass" {3} Food d.priv.rion for 4 d (m • • n [t T J decr",,""" from 19.9 nmollL to 7.6 nmollL)" d. C.nle fed foliage from uurJlma !tu~«pha'" (rommon ruome", mind. trtt, ipil_ipiJ. uazin. pje, and kub.bul.) developed hypothyroxem", .nd hypothyroidism." 3. c.n:ain dog brttds t.nd to h.ve lower [tTJ th.n oth.. breeds. In one study, the m•• n [tTJ in !.rge_breed and medium_breed dogs v..as about 0.5 j.lg!dL low.. than the [tTJ in the .mall_breed dogs." Grryhounds, . nd pouibly dogs in oth.. sight_ hound brttds. ha"" low....f..ence values for [tTJ . nd [IT.] than most oth.. dogs." Th. di"i:nosis of hypothyroidism in sighthound dogs may ..qui .. d. u oth.. than [tT.] {e.g., increased [TSH]}. Unpublished dau for dogs in [h •• ighthound brttds indico" that diff... nt ..f... nce interv.ls are need.d for [tTJ and [ITJ. but not for [tT,] or [TSH]. [I.

[F= thyroxin.].. ([ITJ .. ) A. [nc... ...:! [ITJ .. (frtt thyroxin. roncentmion by aJuilibrium dialy.is) I. Th...me disorders that couse • truly increased [tT.] (Table 17.2) a.. apectal to ao.use a concurrently incr=d [IT.]... About 98 % of hyp'nhyroid cots haY< incr",,""" [IT.] .. when tested." 2. [IT.].. does not al"",)" mirror [tT.] . a. A hor.. with diniao.l hyperthyroidism h. d a normal [tTJ but an inc... ...:! [IT.]...... b. Concurrently finding decr",,""" [tT.] and iner..""" [ITJ .. in cm suW'u the p.... nce of. sick .... thyroid state." For unknown ",asons, sick ao.ts occasioruolly ha"" an increased [IT.].. but • [t T J that i. WRI. 3. T,.AA may com. p",itiv. int..f... nce in some IT. as",ys. but ""lues for [IT.].. a.. not .ffeclal. B. Dec..ased [ITJ .... (f= thyroxin. concentration by aJuilibrium dialysis) I. Thyroidal disord.rs that couse decrnsed [tT.] by dec",.,ing production ofT. are apeclal to have concurrently dec",.,ed [IT.] ... 2. Oth.. disord ... or ronditions that =y couse dec......d [ITJ .. include hYP'",d .. noronici,m, infLommation (interleukin I, interl.... kin 2, int..f.ron." and tumor necrosis f. ctor m.y cou.. decr=ed [ITJ..,), and """tmenU with prednisolone. sulfon. mid... or phenobarbiul. 3. Dec..ased [fT.] .. was found in horus with arerim.nully induced hypothyroidism and in ho .... with • v. ri.ty of illne,s.. {especially with s",ere disorders}.'"

TOTAL TRI[ODOTHYRON[NE (tB) AND FREE TRIIODOTHYRON[NE (fT3) CONCENTRATIONS I.

B.,al [IT,] .nd [IT,] ...... ronv...ion ofT. to T, but have less diagnonic .. n.itivity for hypothyroidism .nd provid.linl. u..ful additioruol inform.tion 0"" [tT.] . nd [IT.]. In dog., diurnal vari.rions in [tT,] we .. less th.n the variation. found in [tT.].'

794

II.

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY ItT J is m=urrd to mOllitor T, supp.... ioll test.

th~npeutic

OOllctlllr>tiollJ alld to

asses.!

oWII~r

compli.llct ill

th~

III.

If a ",Iid.ph ... RIA is u..d to mum", ItT,]. th~1I T,AA call cau.. wOllmusly illcrea..d values just lik~ T.AA in tT. assays (Fig. 17.2). [II some =)'1. T,AA f:.!.dy da: ...... [tT,] alld f:'!sdy illcr ...... [IT,].

THYROID.STIMUU.TlNG HORMONE (fS H) CONCENTRATION I.

Dogs A.

[lIn~~..d

emilie [TSH] I. Primary hypothyroidism: Lack of lI~tiw fttdb.od: b.-causs 24 ng/mL) during and .fter .dmininmion ofT..

c. [eT,] should bt incr have not i>ttll widdy used, .nd th~ir di"l:nostic value compared to oth~r .....'menU i, not firmlyesrabli,hed. lnaCCllrate [TSH] at ve.ry low concentmions (the =y's detection limit is llrar collcentrations found in .... thyroid dog,) could resuh ill inaccurat~ :md pc:rha", mislrading ratio •.

17 1THYROID FUNCTION

799

Table 17.4.1nrcrprctation of thyroid profile result. in dg£ [rT.(]

[IT.(]..

[TSH ]

TgAA

lnt~rpreurion Rul~s

WRl

" "

WRI-i<

WRl-;

;

Positi""

;

Negati""

WRl'

Negati""

WRl-;

N~gati""

;

Positi""

WRl

WRl

WRl

Positi""

WRl

WRl

;

Positi""

WRl

WRl

;

Nc-gati""

TI>< ..Ji.bly cstablisW.

• Sul£omethaumlc_ttinmboprim. pr«!nisoJone. 0' pl> of • • """'cit-l .... ~, thpid ~." i" ............ pl",,( hypotloyroid In",., IJ,I06-IIO. 25. G..b.m PA. Rd'taI KR. N.d. ....... RF. r...v...d., .. BoUip AI.. 2000. Th, mcaN"""'" ofk~n' th~ (TSH) .,in, . ~ ani... immwoo"Jiom"''''.-y. / Y" In"", Mod 14,j42 (. b..ract) . 26. T .... " H. K..do K. Hooikoobi H. Mi....loi",. H. Okau..li T. 0 " " E.. 1991. I""""ted prim..., .hypotbyroidiuo ...ith thppI ..;. in. do" / Am Y" Mod A..oc 181),1476-1478. J6. G..b .... PA. N~ RF. Rd'oal KIt ~BoII ~ , AI.. 2001 . L,....pbocytk tl.J""'iditio. Y" CJin No"," Am SmallAoim p,." }h91~J}.

BIl2

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

So""""',

J7. B.to.. RL. HoonofWJ. 19l!2. im.&inc fo. d" ovaho";"n eltl.Y""id ""'pl.... ...d Ioypotkyroidi.., in • doc. J Am Y" Med A_ 180,)("77_ lon. 4S. a. .. t>inCB, McN«ISV. G ......... CL. P,..ani", SC 19l!J. ~nital kypothyroidi.m in " dor; du, to on ioo< a,"", kypodtyroidi ....1 J S...n Ani .. [',"'. 40,152-1 57. S5. Kaotroow .. LB. P''''toO M E. T "P"'"" ]A ""tim C. Nicl.ol. R. 1999. s...... tot,) ... ,....;.... total ttiiodo"'yro· ..itt,. fto< ...yro.;"' . ........ pctropin oon«ntn.tion. in I>tion of coni",]:and ald05tero ... ..anion. • CRH ",1.1>«1 from tbe hypothal>m"".timuJ. ... the p,odoction and "'I.... of ACfH from the pituiury glmd. ACTH stimula... the production :and ",lea>< of cortisol :and aldost",,;"'pJas;", but it mould nol cau.. th. clinical monifesmions of p"thologic hyp< rnim:d h.. clinical manifest. tions (~.g .. polyuri. or .Jopo>rts {Fig. 18.2} A. Dog,"~7 l. A {Cort:Crt}. "'tio chat is WRl i. mong ~id~nct chat • dog d""s not h."" hy!",,,,drenoconicism. but incrrasN (Cort:Crt). mios .'" freq""ntly found in dOl}! without hy!",,,,drenooonicism. [n oth~r words, the (Cort:Cn ). "'tio has a high di"l:nosti, .. nsitiviry for conine hYl"rad«nooonicism (r~lativc:ly f~ f:d .. negativ.. ) but has a poor positive predictin v:due and poor di"l:nostic sp«ificity (r~lativc:ly frequent faJ .. po,iti=) (Fig. 18.2). 2. Basal (Con:Cnj. ratios connot rdi. bly diff"entiatr PDH from FAN, but th~ gr~atm ratio. are usually associated with PDH, as is suppression of {Cort:Cn}. ratio in conjunction with . HDDST." B. Cats:" Th~ (Cort:Crt). "'tios in 15 of 32 cots with h)'l"rthyroidism w,,~ greatrr than the up!"'r r.f"enct limit of th~ fdin. ref.",nct interval (8.0 X Ia-' to 42.0 X 10""'; n = 45 ). For th~ h)'l"nhyroid COtS, the median mio v:due was 37.5 X la-', with two values .bon 100 X 10..... The gr~.t" (Con:Cn). ratios may ~ ",fl~iv~ of the stress

18/ ADRENOCORTICAL RJNCTION

'" "" ""I ~450 ~

-'00 -"

'"

i

study A

' 'I -=':1

Sludy B

~1000

:'i

~ '00

..,...........

None ... .,..

oorIIrtM th~ ratios in truncotal form (~.g .• 0.00}-0.(7). wmples of th~ cokuution! are pr=ntal in Eq. IS.2.

U,ing mol .. ron""'ntutions: Conisol:ACTH Ratio = 48 nmol cortisol(L 7.4 nmol ronisoi 7.400 pmol cortisol 6.5pmol ACTH/L pmol ACTH pmolACTH Ratio r~portM in the articl. for the .. data would hoy. bttn 7.4. U,ing wtightlvolum~ con""'ntratiom: Cortisol:ACTH Ratio = 17 J.1g/ L conilOljL 0.57 J.1g conisol 30pg ACTHjL pg ACTH Ratio ~ not reponal in th~ anicl~ for th.", units. III.

{IS.2a.} 7.4xI0'

{IS.2b.} 570.s defin«l ... postdenmeth...,,.. [oonilOl] . o If r.. ula from LDDST :md HDDST .,. e""mined toll"tbrr ." the", .... in:odeq"'''' rupp",uion of corsi",1 ooncrntr:otiom in both ..... in ",,:uly:ill dog. with FAN (D ..,d H: 94 %) but in . minority of dogs with PDH (B. C, ..,d G: 24 %). A f... dogr witb pDH (14 %) ..,d two dogs with FAN (6 '!O) had i",dequ,,,, Sllpprersion witb tb. LDDST but had :odr'''' suppression with the HDDST. Two dogs with PDH ppr .. sion witb tb. LDDST but inadequate ruppr ... ion with tbe HDDST. (I %) had HD. high d ....: . nd lD. 10.. 00...

.dr." ....

816

18/ ADRENOCORTICAL RJNCTION npa;t«i to bt da;t""...,j dramaticolJy >t 4 h and 8 h (Fig. 18.4A). v.lu .. . ", usually i""d'"'juatdy suppress.d at 8 h with both PDH and FAN. (I) Mon _"inarians int~tpr~t a pondn;;omecha>one [ruttisol] < 104 J.Ig/dL (< 40 nmollL) to indicate th~re was .d'"'jlIate suppression of coni""l secretion. This da::ision threshold . ppear> to h ave been calculat«i from data rulJa;t«i from 22 healthy dogs; it repr~..,nt«i th~ m""n concentration (0.5 J.Ig/dL) plw 3 sundord deviations (3 X 0.3 = 0.9 J.4::ldl).t

8 h. ,~'" {2} Some authors propo.., th at suppw;:sion i. present if the postdnamethaoone [coni",l] in the 4 hand 8 h samples i. < 50 % of th~ pralexamethasone concentration. Such .n interpr~uti"" guiddin~ i. comistem with the half_ life of plasm. coni..,l. b. If hYP"rad .. nocorticism is cou.«i by PDH or ~ctopic production of ACTH. th.n a low do.., of dnamethasone m.y or m.y not l.ad to supp ..... d rdease of ACI"H by nalplanic pituitary cdl,. and thu. cortisol production from hYP"rplanic adrenal glands mayor nuy not da;",ase (Fig. 18AB .nd C). {I} In som~ ca5e'l. the 4 h postdu.. methason~ [cortisol] is btlow th~ da:ision thr.. hold. but the 8 h postdnamethasone [coni""l] is .bove the da;ision threshold. In such the escapnl suppression i. highly indicotive of PDH if the clinicol 'igns suppon • hyperadr~noconicism diagnosi •. Nonad",nal disorders may aloo bt associat«i with this pattern (Fig. 18AE). {2} Suppr=ion i. demonstm«i in mor~ PDH """,. if the "< 50 %" criterion (Fig. 18AC) is us.d rumparal to the "< 104 J.lg/dl" (< 40 nmoUl) criterion {Fig. 18.4B}. c. If hYP"radrenocorticism is cou.«i by FAN. then low_do.., dn;;om~tharoM is not npa;t«i to da;r"".., the secmion of coni501 (Fig. 18AD). Even though suppres_ sion criteria a.. nor fulfiJl«i. rurtisol concentratiom may Huctu ate during th~ testing. btcou.., of variations in cortisol secretion by nwplastic cells. binding to prot~ins. or plasma clearance. The WDST has high diagnonic stnsitivity for FA N. d. Supp..ssion may not bt .d'"'jlIate in dog. with nonad",nal illness (Fig. 18AE). e. In two dogs ..",iving phenobarbital therapy. coni",l concentrations were not suppr~ss«i ad'"'juatdy. possibly because phenobarbital·, dfa;u on cl""rance of synthetic steroids enh.nce duamethaoon" d""rance rate. HoWat. supp",.. i",,;' 6f'K'.d in no,..dr.n:d w.o,dc .. , • Dog 2 had . dren:d byperpwi. co=t> PDH or nonad",nal disorders, In tbc HDDST, suppression con be found .. itb PDH and i, npK«d..ith nonadomal disorder> but ;. not consi,«nt .. itb FAN, 'Dog 3 _ bealtby OJ had PDH or a nonad«nal disorder, In the LDDST, mpp,cssion can be found .. itb h",lth, PDH, and nonadJ.n:d w.orden, In the HDDST, mppr ... ion ern be found with he. ltb, PDH, and nonad,en:d disordc ... Suppres1ion ;. not ~tesl ..itlt FAN, 'Dog 4 bad adJ.,..1 hyperpl.,i. co.....! by PDH or . no,..drcn:d disorder, In tbc lDDST, b ilu« to SUPP"'" tbe [co,tisol] to 250 nmollLl, then th~ d=>ge i.

021

18/ ADRENOCORTICAL RJNCTION

incr .... sn!. If th~ dog h .. continuing clinical signs suggrni"" of hypoad .. nooonicism and th~ post_ACTH [conisol] is < 0.811g/dL {< 20 nmollL}, th~n tr~>tm~nt is discontinu«l."" 11.

Cats A. Low-do""

de:um",h:ason~ ,uppr~ .. ion

Ie;{ (LDDSn: not recommend..,j

I. Procnlu~ B..,ically Ihe same procedure as for Ih~ emine LDDSf aa:pl daamelh_ ason~ is given at either 0.01 or 0.015 mg/kg IV. Some people ..ftr 10 use of a 0.1 mg/kg IV do"" a. a LDDST in em, bUI il is oofl!ide=l a HDDST in thi, lal. 2. Expect..,j ... uln" {Sp«ifi, I"'tient =uh. should be int.. pret«l by using ",f..ena: interv:d. and interpreYlion guiddine> provid«l with ... uln.} a. In h..lthy cats, the 4 hand 8 h cortisol oona:ntralions a.. um:dly < 1.0 ~dL {< 30 nmoUL}, but Ihey ..e nol suppress.-d thi. low in about 15-20 % ofh .... lthy cats. Coniwl suppression may :dso fail to occur in cots with non. drenal illness. Therefo.. , the lDDST has poorer diagnostic specificity than the HDDST {for which conical suppression fails to occur in very few cats} :md thUl i, not recommend«l. A postdeum",hason~ [cortisol] of 1.001.411g/dL (30-40 nmoUL) is con'ider.-d a bord..line r~sult. b. In cots with hy""rad .. noronicism, the 4 hand 8 h oortisol cona:ntr.ltiofl! a", apect«l to be :> 1.5 J.lgldL (:> 40 nmol/L). B. High-d""" deum.thasone supp.... ion t.. t (HDDSD I. Procnlu", a. The initial protocol is the same as with the conine HDDST, but I mg/kg daamethasone is aho used. Som. Jl"Ople ..f.. to a 0.1 mg/kg d""" as a low dose in cats .nd oonsid.. I mglkg a high dose. Others cofl!id.. th. I mg/kg an ulm_ high dose. b. em m.y the supprnsive: dfecn of de:um",hasone fm .. th.n dogs, I 30 min and 60 min or jun at I h. 2. Expect..,j ..sui,," a. S""cific I"'tient results should be int.rpret.-d by using ..f... na: intervals and int.. pretation guiddin.. provid«l with results. b. A healthy cat should have:. p",_ACTH [cortisol] of 1.0-6.0 llg/dL {30-170 nmollL} .nd a pon_ACTH [oortisol] < 13.0 J.4:/dL {< 360 nmoUL}.

=""

.22

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

c. Cau with hYp'rad .. noconicism =y han a p, .... ACTH [oorti""l] WRl or incrrasnl. and a 30 min or 60 min post_ACTH [cortisol] :> 16 J.lgldL {> 440 nmoUl}. Ho~""r. only .bout 40--50 % of em with hypOnal variation in [ACT H] . results of the '"'Iuin~ daamrthasone suppression test " r.,,~ diffe",nt in January rompar 1.8 tim .. th~ p..s;omple·s [rorti""lj.

c.

COMBINED DEXAMETIlASONE SUPPRESSION- ADRENOCORTICOTROP[C HORMONE (ACTH) STIMUlATION {RESPONSE} TFST The major advancag. of th~ combin«i tost i, that it combin~. adrenal :as.=sm~nt into on~ diagnostic procfflu",. and thu, only one ~ of s;omple; is submitt«i to a rd'trence laboratory. The major disadvantage in doC' i, that it doo; not han the ",me diagnostic power as the combination ofWDST and HDDST don~ individ .... lly. I.

Canine m~thod" A. A ,ample for a ba",l [conilOlj is collect«i. and th~n daameth. lOne is :odmini'l .nd incre.s.d "!dost~ron~ to pla,ma r~nin activity ratio,." Th~ cats we .. not hyp'rnatr~mic •• nd "'m~ d~lopal ren..! l.. ion, ron,istem with p'"i!l~m hypen~n,ion. 3. Anoth .. cot hod an .d.. nocortical carcinoma that produa.d exct.. ivt .mount, of "!doneron~ .nd prog~steron •. The resulting clinical Jign' w..e due to the effect, of progtsterone (i .•.• diabete'l mellitu,) mo .. than to "!doneron~ effects."

Ill.

Aldosterone con""mrations in oth.. conin. disorde" A. Th... is not a cleor "'p'.. tion of pr ... ACTH aldosterone oon"'ntrations betw..,n h."!thy dogs .nd dog, with hypoadrenoconici,m. How"",r • ..!do't.roM roncrntratiom in the pon_ACTH "'mples w..e lower in dogs with hypoadrenoconici,m than in clinicaUy he..!thydog, (Table 18.5). B. Dog. with PDH hod ..!dosterone roncrntration •• imil", to th"",,, ofheahhy dog. in both pr ... ACTH and post_ACTH sample'l (T.bl~ 18.5). C. Som. dogs with non.dr~n..! dilOrde", had. vtry high [..!don.rone]. The high con",n_ trations ..~ probably rd.trd to hypovolemi.> or dec ..... ed dfc:ctivt blood volume (T.ble 18.5). D. Result, of. study of 31 dogs with PDH. S dog, with FAN .• nd 12 h... lthy dogs:" I. Aldosteron. oonctntmion. we...ignificontly lower in the PDH dog, than in the h~..!thy dog,. The authors suggc:ned that und .. chronic ACTH nimulation. some of

T ab .. 11-'. _ " ' .. 00&< • •

" " ; '. .

f, .... ACnl ,,;......... toot. i. dar Al. 2 Failu.. to , .. a dec ..= in [wsillophil] or failure to..., .n illc..asaI n.... trophil to lymphocyte mio nt...dmininmioll of ACI"H sugge;ts the pr=lIC< of hypoplastic or atrophi.d ad",,,,,l gland •.

IS/ ADRENOCORTICAL RJNCTION

027

B. lncr~a~ ~= of obtaining ""rum or plasma conisol con""ntrations and th~ir sup..ior diagnostic va.lu~ ha", mad~ th~ Thorn t~st and mooifi«l Thorn t~st nrarly obiOl.te. Howe""r. th~ rdationship be{v..""n blood [conisol) and blood leukocyt~ con""ntrations should bt ",membtr«l when int~rprffing routin~ romplet. blood count results. II.

Con,entrations of oth.. steroid hormon~. A. Adrenal glands produce other ,uroid hormon~s. induding int.. mediates in the .ynth~tic pathwaY'. l. Inc",ased pro!:"st~rone com:entratiom han b.",n r~ported in dogs and a cot with FAN."'" 2. In a study of 53 dogs with confirmed hyperadr~nocorticism {including PDH and FAN o>« .. "atioo, in ..."'" and pi ...... of oi ... , HS, ru;ob..k A. van +. bicorbonate. alld phosphates) and sm:ollllollprouin solutes (•. g.• glucose. u..a•• nd Cn). Other thall [prouin}. the imerscitial fluid adjacent to most copillaries has dectrolyte. u .... gluco ... alld Cn con""mr.tiom .imil .. to plasma.

19/ CAVITARY EFFUSIONS

B33

p I

Parietal Tissue

e

Inl erstHium

C"'-'; , -- .. -, ,

Capillary

:, ,

--t+ ,, ,

~

1--", -----_.'

Lymphalic vessel Slomata - . ':.

u r

a I

Pulmonary Tissue Interslilium

C----'; , --- .. -, +-:i, Capillary ,

F

I

. ' 'd' U

Lymphalic vessel

i

Fig. 19.1. PLeur:.l 8uid form. non md rem"""'. Forceo of St:uling'. low mov< prot in dogs, the .mounts of pleural .nd peritoneal fluids in hralthy cots "e very small. '" it is difficult to 0011= .uflicient fluid for anal)"i •. [f fluid con be: ooJlrctw, the fluid probably rq>rr"'nts .n effusion. Equine pleural . nd J>lr con um:dly k r..adily diningui,h«i from a typic;o[ exudat.; but /lUlly atrav.scuJ., fluids are modjfiffi transudate< or modjfiaJ exudate. with some chana.riniCJ of both, so r~ni_ tion of th. etiologic process may k difficult without a mo .. complete n:lminarion of the fluid."" Modifial transudate v,as Jistw :as on. tYP' of .ffu,ion in , 1977 ,,",urinary clinical pathology textbook." It is now" common l. btl or clowificat;on Nen though it moy not :K:CI1ratdy rrftrct the pathologic proa.. responsible for Ih • • ffu,ion. 2 Th. modified tranmdatr cl.ssifi"'tion is usually basN on J.bor.uory data r>th .. than the pathologic proass or pr 100,0 X 100IJll} may, Whell"""r ill doubt, the values of Huid with suspended cdl. con bt romp. red to the Huid', suptmatant, 6, A vari 100.0 X 1001J.ll} . ", found in exudate> and neoplastic lymphoid ~ffusions. VI.

Micro..::opic examination A. Wh~n cavitary effusions are d= and colorl~ .. (i .•.• look lik~ H,O .nd th ..efore ..~ prouin_poor and cdl_poor transudates) •• microscopic examiruotion of the fluid typically yidds very linl. useful information. For all othu ~ffusiom. the microJCOpic examin. tion of scainal cytoprepo.rations is frequently the most imponant p. n of the fluid analysis. Part of th. microocopic examin. tion is th~ aamination of ""n •• but examin.tion of oth.. structur.. and f.~tures is ~u.ntly imponant. I. Scains designa! for blood films ... fr~u.ntly used for the routin~ scaining of cytoprq>.rations. On~ major adv.nt"i:~ of using the blood st";m i, that people are f. mili.. with th~ staining of blood cdh and similar f•• tur~s ar. found in th. nud~ta! cdls of ~ffusions.

852

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

2

Th~ microocopic examin ation should indud~ .11 pm. of on~ or mor~ cytoprep."'. lions ~"'" of th~ potenti'" un.nn distribution of ~Us :md ocher microscopic

structur ...

B. '\hjo. :up«:ts of th. ""amination .'" as follows:

!'"'"

l. Nucl~t«i cdl diff.",mial count is done to determine pe=nt"l:"" of ....ch nud.... tions of ram cdl typ< can b. Gl.kulated and int.rpmed. For n.:Impl•. 60 % neutrophil, in a fluid with" TNCC of 1.0 X IO'fIlL is intupr.tn! differ.ntly than 60 % neutrophil. in a fluid with a TNCC of 100.0 X lo'llJL. If cd] ooll",lIlra· {ions are calculated from the perctnt"""., thpl~ indud~ ntesothdial ""US in th~ diff,,~ntial cdl count, .nd othm do not. If th~:are not indudtd, it is mo .. difficult to interpret thelNCC, and con""ntr>tions of oth« nud... ttd cdl, cannot bt calculottd or cominendy esti_ m. ta!. Mesothdial ""lh ar~ oft~n in dust~rs, so th~ir indusion may l...d to incruKd vari.bility of the diff"ential munt, deperoph~ ... or tran,ition pha.., occur in fluids. but they may aU ~ lumped into a m:>eroph~. category once the cell, have left the vasculature. b. Th. cytoplasms of m.croph:oges f""cuolata! cytoplasm, or contain .ngulfnl m at"ia/ :u. =;Iy recogniud. How.ver, som. r~{ive lymphocyt •• and ,mailer monocytoid or hi,tiocytic cdh a", not ~asjJy difftr~ntial md Crt .r~ n~.rly th~ sam~.

C. Wh~n th,,~ i, • r..ant .ddition of urine to ~riton~.t fluid. the r=.tlting fluid wiU h.n. gr~.t~r [u.....] and [Cn] thm pl.,IlliI con""ntrations ~= th~ [ur~.] .nd [Cn] in urine a.. typically much gre>t" thm pl"'ma or .. rum oon~nt .. tion'. With tim•• nd with diffusion of mol",ul .. du~ to con~ntration gradi~nts. the [u",.] .nd [Cn] in the extravascular . nd intnv;oscul.. fluid, will b«:om. similar :again • • nd both wiU k inc",asnl. I. Aft~r 45 h of ex~rim~ntally inducnl uro~ritoneum. the [Cn] in th~ ~ritonnl fluid woo. about twi~ the .. rum [Cn]; Th~ m~an ~ritone>l fluid [Crt] wa.< 11.6 mgldL (rml:". 5.5-15.6 mgldLI. wh"•• , the mun ",rum [Crt] was 5.2 mgldl (ran~. 1.2- 6. 7 mgldL). How"""r. th~ [u... ] in the effusion .nd ",rum at 45 h w~ .. nearly tho same. Th"", dau support the fact th>l u",•• nt.rs the blood fast" than does Cn. Azot.mia (.ith~r an incrn=\ [ure.] or [Crtll was det~ctabl~ in. f~ dog, within 5 h bur in :all II dogs by 2 I h after "ruptu ... " Th...rum [u",.] .nd [Crt] oontinun! to inc..... onr the 3 d study." 2. [n. retro'pectin study of 13 dog. with uro~ritoneum. th~ cr.atinine oon""ntn_ tion, in ~riton~al fluid w",e at l~.. t twi~ the "blood·· con""ntrations in II dog•. Th. durations of the sponunu>us rondition, w... not known. (Note; Th~ .uthon did not specifY wheth~r the "blood" c.....tinin. oon~ntmiom w~ .. ",rum or pl"'ma oon~ntntion .. )" The ratio. for .ight dog. with other ~ritonnl dfu,ion, were from 0. 7 to 1.2. 3. Ratim of ~ritonnl fluid [Crt] to .. rum [Cn] han ken r~ported for other anim:al, with uro~ritoneum; foal, (mun. 3.5; and ranI:". 2. 7-4.6)." horse. (;> 2.0)." and cats (m.... n. 2.0 md rang.. 0.8-2.4)." Th~ ratios can k u..d a,. guideline in the interpretation of data. but oth~r .. peets of the ca.. .should k carefully ron,id"ed. For enmpl •• a cat with a urinary tract ob,truction IlliIy ha"" bttn """"rely .7.0temic kfore th~ uro~ritonalm occurrM. Thm. the .. tio m.y not k;> 2 wh~n the cat is first enmined.

858

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

D.

U""~ (or ur"" nitrogS m~a,urM in fiVlant of avitary ~ffusiofll. Some ion_ .dective electrode methods require a proteinaCft>us fluid, 50 urine or a uroperitoneal effu,ion may not be accq>table. Anions oth.. than ct may rract with th~ d=rodes of the ct ass.y. For ""nul", .ampJes, measured [K1 might include K' rd=ed from cdls either in vim or in vitro.

IV.

[L-lactate] A. L-la.ctate i. the product of anaerobic glycolysis, and one reason for hyperlactatemia is tissue hypoxia (sts greater in colicky horses with intestinal ischemia secondary to strangulating obstruction (8.5 ± 5.5 mmoUL, mean ± standard deviation) comp",ed to colicky horses with nonstrangulating obstruction (2.1 ± 2.1 mmoUL) and healthy horses {0.6 ± 0.2 mmoUL)." Th~ [L_la.ctate] in "'Iuin~ peritoneal fluid i. u=i as an indirntor of the .everity of intestinal ischemia in rolid:y ho"" •. 2 The [L_lactate] in peritoneal ~ffusions was greater in dogs with intra_abdominal neoplasm. (h~mangio.arcoma, arcinomatosis, neur""ndocrin~ rumor, "...,tastatic

19/ CAVITARY EFFUSIONS

os,

..d~lIocarcillom., and p.ncr""tic carcinom.} {3.8 ± 1.7 mmollL, m""n ± stand"d d~i.rioll} than in dogs th.r did not hav~ abdominalllUst conjugata! bilirubin is diffu,ibl~ and pl.. m a proteins ar. pre.. nt in most nontranrudative effusions, th~ [bilirubin] in most ~ffu,ions should bt .imilar 10 the strum [bilirubin]. Th~ major exctplion to thi. con""pt is =n with bile p"ritonitis and th~ formation of a bilious exudate. When damage 10 bile dum or gallbladder r.. ults in th~ l~akage of bile into the p"ritoneal covity, ~rilonitis will devdop and the r.. ultant exudate will have an increasa! [bilirubin]. B. The", >re stveral potential COUstS of bile entering the p"ritoneal covity, induding blunt or p"netrating lrauma, bile duct rupture secondary to manual expression of the gaUbladder, necrotiz.ing cholecY"titi. or cholangitis, rnoldithiasis. and neoplasia of the biliary tissu ..." C. When the effusion d"",lop.'l .econdary to bil~ l~~, "rults of Huid anal,..,.i. reveal the p".. n"" of an exudat~ that typically h .. a [TP...] :> 2.5 gldL, a T NCC :> 5.0 X lo'lJ.lL, and:> 80 % n.... trophih." I. Microscopic ex;omination may deta:r a .mall to large amount of intra""Hular or extra""Hular amorphous yellow to brown bil~ pigment, or bilirubin crynal" extn_ ""Uularlyor in macrophages. 2 [f the bile l~ is secondary to a baclerial infa:rion. th. exudate may ronuin intracdlul >r or exlracdlul>r bacteria. 3. Typically, the [bilirubin] in the bile-rontaining effu.ion. will bt at le ..1 !Wi"" an animal". strum [bilirubin]."-" 4. When a gallbladder l.. ion ~nabl .. in mucoid secretion (coUa! whit~ bil~) to ent~r the ~rilon..aJ covity, the resultant effll'lion may contain light basophilic mucinom m aterial wh~n ,uina! with a Romanowsky stain." D. Rerults of blood and urine analy.is will depend on th~ COUst and duration of the biliary lracl leakaj:e; for example, if the animal had obstructive rnolesmis prior to bile leakage, hy~rbilirubinemia may h ave pr~ed th~ bil~ ~ritonitis. However, with trauma_ indu=! bil~ l~akagt, the hy~rbilirubinemia occurs aft~r the onstt of the bile p"ritoniti •. Likewi .., an inflammatory leukocytosis may bt Ihe result of a bacterial cholangiti.

19/ CAVITARY EFFUSIONS

86'

that couses bil~ l~~, or an inHammatory l~ukocytosi, may occur aft~r th~ on.. t of arut< bil~ ptritonitis, E, Bilirubin assays that a.. design.d for .. rum or plasma ... mple. {."" Ch'ptu 13} typically em k ustd to analyu th~ .uptrnatant of ~ffusions. Bilirubin is dd. IN, Amt.ia.n Animal Hoopital Aaoociati.on. 6. Co...!l RL. Ty\« RD. 2002. [);.,...,.;, C)JtO!.p."J H.-.!.p of do. H.",. 2nd odition. St tn..l" CV M ~oby .

."

FUNDAMENTALS OF VETERINARY CLINICAL PATHOLOGY

7. VIlIi,n E. Bt.choood L. cd •. 2005. 11&1 VA M ....J ojc..;." ~"" F.ii_ C/;,,;..J P-23 Adrenocorticotropic bo"""",,, (ACTH) conomtr1tion, 813_ 14, 814f cortisol, pt.rrruo ratio to, 814-15 "imut.tion test emu.., 818-21, 819f < (All), 6OW- 52 octivity, in=»«l ..... m, 651. 651. uulytical con""p". 651J.-51 psychoLogic process'" for tot:d, 370-72 pby.ioLogic pr0=s UN:Cn ratio:tnd, 438, 43-St in ho..... , 477, 478t .. rum ch.mittty result. in, ,bnorrrW routine,

« I""tr."uJ, 430t, 431 p",,,,n:ol,429-3O ru.ord.n rnd, 429, 430, ",tul v" 477, 478t ren.!, 430-31 pr ... n.! v" 477, 478t r.n'! di....... rnd, 433 ren.! f.oilw., .ru.. :and, 428 .. rum m.mistry =ul" in, mnorm:ol lOUtin

UN in ......",Ipw.n.:and, 435 ureJCn wirucy acr.,ion :and, 429-31 Uf'" production, inc",....! rnd, 43O~ 431 _32

Bal",;.. spp" inf«tioUl hemolytic

,"

.nrmi.,

B:oct.,.iuri,,472 B... acrss in blood (BE,,), 567-6S B... aceu in ECF (BEla)' 567 B... ucetS in pw.n. (BE.), 567 B1tOf"'ni:o, 88 B1SOf>hil a>nomtr.,ions, mnomW, 88 kinetics, 59-60 pools, 59-60 B1SOf>hili., 88 diffusor cyhilic "ipp~ng, rry=>r>, 690-91, 690f . nt,ic cirrubrion of, 690 excr .. ion bilivy, 691, 692f dra.=ret.rion, 691 uri"", '0 COl .. rio, 485, 696-97, 697, Bilt 691 Bili..,. di ..... , 6n Bilirubin cholrnui. rnd, 6tH conc'" of, 683 phJ"iologic p"""'.... of, 681--.'13, 682f conjug.t«!, d.cre:ased rxcr .. ion of, 687--.'19

C,''',

m"',

rlJwion rn.!";' with, 861 hemolJ"it rnd, 684-85, 685' hrp>,ocyte up ..... of, 685-87, 685' byperbilirubinemi., 684--89, 684, icterus, hemolytic rnd, 684-85, 685' m'bog< kine"". hypoblemic mY"P .. by in.

'"

Burr cell. 147 Co'+. 5., C:dcium Cocbectic ....... protein oyn,hesi./",ubolism.oo.

'"'

C:dcitonin ronunmtion. 630-31 C:dciwn (Co'",). 593--631 ..,iom. dilfusible binding of. 608 ..,rioo>glll..,,, binding, 611 _ 12 bo .... 596 chloride. do'ting .00. 281 concwru.lar) hrmoglobin roncrntr:otion mrrn Chrdiak_Hig .. hi .yndromr. 99 Chemistry .... y>, 8 Chlor:unphenicol •• rytluoid hypopb.i. ""d. 339 Chlorid. (0·) o.limmucy tnet funetioJU peI. 63~9 1inophili., 86-1!8 co ..... , 86-S7, 87t tion with, 153- 58, 154t kinetics, 112 megalobwtic . ... mi •• nd, 201 _2 met.bo~c defect in, hemolytic .... mi. rnd, 1s6-91 met.bolism of tn1rure, 115, 118f metbemoglobinemi. rnd, 198-99 morpbologic ' ¥:Im. tion, 120 morpbologic f""rureo of, 135- 51 orgmi",u, 138, 139t o"""Wity,I30-31 oxidrnt ..potwe ai, 198-99 patbogea..si,,13'>-51 pby.iologic pJOCelSe'l, 110_20 polyduom1topbi~c, 138 P=""",,", 110 p«>ction, anemi. rnd, 158-60 QBC mal)"is of, 127 roulem, 136 rubricytotit, 136-37 'k"!",, abnormal, IH- 51, l+it ,iderobl... ic ..,.",i. in pwu' 90- 92 bone nuno.., 342-57 clossific. tion of, 342--46, 343t g< ... r.l amethic hyper.. gmmttemi., disoro.r.lp1thogr""... cowing, 541 _-12 Hyper~p ... mia, lPS and, 667

Sa"".

Hyper~pemia,

n3-78 1ttem and, 382--1!3 hrmoronam'ration and, 379 hype (1D), 653 octivity, incrr»rd orrum, 652t, 653 Loctotion hypom..."... mio.oo, 625 Loctooe toler.,,~ ttlt in h''''et, 756-57 Loctosuria, 517 lAD, Sn u..kocytr odhesion deficirncy u..r /low crU cytometer, 64-65, 64f rJYthrocyt., 125-27 pbtekt; :on:oIJ"is with, 230- 31 Lota >gglutirution imm=J", FDP, 2% lD, Sn lac"" clebydrogrn ... LDDST, S" lo....-do.e clenmetlu.onr mppression

"""'y,

~,

LE, Sn lupus rryrherrutosus (lE) lre- White mrtbod, 279 lrft dtift bLood ..... trophil roncentntionr rnd, 70-71 cIDsmc1tion, blood neutropbil ronerntr1tioas ...d,70-71 clrgrnrntive, 71 nruuophili. rnd, 72, 73f rtemic lupus erythem1ton" lympb. denitis. 363 lympb. denop1tby.358 lympb noo.... 58. 323--65 analysis. methods for. 3511-63 .. pir:ltion. 362 biopl)".358 m.jor fe. tures of. 359-62 colis in. of ho:dtby mom .... h. 362-63 clusification. 363--65 hyperpl .. i•• 362 lympbocyte< in. 59 ID1jor conc",/tetrru. 358-63 noopwi •• 351. 363--65 re:octi"..363 umpJe.. cytologic. 359--62 lympboblm•. 363 lympbocytes. 56 blood. 58 processes infl.,."cing. 59 bone autro..... 332 conamtr1tions. mnorm:d. 81-35 effusioru md. 86'5 hem.topoietic cells rnd. 326 kingoeytic .ytt, 227 microoropic fut"'" of, 232-33 gcu... 427_29 1ZO«aW. and. 428 b~oemi . and. 609 urine voIum< and. 429 bovine, 524 ct+.oo. 601 chronic, 425- 27 c..". h.., concentr:otion.oo. 613 md.enc< of. 427 polyuri. in. 427 "",..l con",n't1tiag ""i~ty :md. 427 in horses. 60 I hypoblemic. in 519 N.+: K' t1tio, d.eJ>amtr1tion. inc",.....! in. 691 - 93. 692f.692'

ci' i'xto" d.t .. mining. 595- 96. 59'5f IOu] ronconmtion. 59-l-95 ",tion. 535. 535, cltol"n .. ol roncenttotion in. 767- 71 CK. incr""'! octivity of. 662-63. 662, . k fo" 500 tion md. 499 .lJwion m . l}"is with. 858-59 e = group, 502-3 H,O :and. 499 hYl"" ... oemi. md. 501 - 3 ion activity. 500

,-

H,O Jo.. . nd. 502 ,,,,,,.ring :and cut:meow. 507 third... p'''''' 507 nephron ",.bsorption of. 499 pwm. osmoWity regulation md. 499 qumtiution ... mpLe fol. 500 lenoJ tubule function :and. 418-19 mining. 501! ..... ting 111 CUW>eOUS Jo.. of. 507 Sod.iwn mUi", (N. ,SO,). 401 _2 Solu",. 5% Spectrin delici.ncy in Dutch golden reo~. 201 Spherocytes. 143. 150

',,-, a>ntnction, erythrocytosis .:w....! by. 196

erythrocyt ... 111 _ 12 pl>",Lets in. 2IJ Spo:.. S« P.. cent hemogLobin ..",... ion .. ith ozygen of lIterioJ hLood by pulse o:xUnftty SSA. Sn Sulfuulicylic ocid Suining 1ZUrophi~c. 62 I=ophilic, 62 bLood. 61--62 """inophilic. 62 neutrophilic, 62 Surling" bw. 405, 406f aviwy .ffiuio... 1I1d. 836-37 Stem ",lis, 55

Steroids. hypeoglJ=mi' 1I1d. 714. 718 St....,t·, "",thod of ocid_b.se ' M}"is, 584-91 delinitioru.585-116 Stooutocytt:ol alIoimmunpl .."",.oo, 242---43 pbtJ>omtr .. ion. 789-93 di.b."", .... Uin.. induc.d by. 717 f",~ . 793 hypergly=ni. :ond. 718 hyperthyronmi .. 789-90. 789t hypothyrournia. 790-93. 79h TSH ..,d. 798 TIBC, Sn T oul iron_binding capacity Ti...,., foetor (IF) roogubtion tert. 282-83 PT :ond. 282-83 ltrm< foetor pathwoy ro. gubtion inhibitor (IFP!).

rn

T"'-

m

lymphocytes in. 59 lymphoid. ~ DNtrophils. 58 Tn Sn T rypsjn_Iike immuDOr ..etivity T-lymphocytes. 55 TNCC. SH T oul nud..t.d ""J[ ronamtntion TN remltt. SH True niologic pr""""",/coJ>C-27 renn i..... llici.ncy, cbronic, 42'>-27 renn rubuJ. functions in, 418_23, 420f UA.oo, H41--41 qes in, 628-29 endogenow, "'Ul"'" of, 600-601 nogenow, """"'" of, 600 fonn1tion, 628_29 hyporviumi""";" neopwm.... oc .. «d, 601 hypovit:uninooi., 604 rid"", rnd, 604--5

umple,629 Viumin K rntogonittt, 305-6 bt...ding dilOrden rnd rnugonism or deficiency of, 305--8, 307, deficiency, 306 hemonh>ge rnd, 306 hemotu,it rnd, :abnormal , .. ul", in,

,.m

,,'-'

Vomiang, K· lots through,S 18-19 Von WiUebrrnd disen. (vWD), 265-66

""quirePiOPloo_ , ~ .. _ D6IaI. t.odi.., " ' -. B. Tooic .......,.t.a. ~ c. T.u: p ... ""'~ ,.;,., .oo..bI •• ",In. tnt! !Ollie boad """...p,a. ....

D.

Hypdooo.l ~ . . . pc/rdoooal _ b y ..nh «.rirtcd ""em..... I. th;, c-. • p". . . . ." .... diac-- of fdio, ;olCroou. "',........ ...d "'" . b""", of B.lymploocyo, n«>pIao;. i.odkotod tho, d., J.rp.'I''''''.......... b)]>al. bwaio.=«I poIyd.o...J """....".thy. I. ,IUO ""' . dind ';P' aod .....=cly h;p. tit" .. E,i,,{J,I,,,, ''''"' ;".d;,cotod thz tI., hrrOa«""- '" ""''''' .....~ Co_. of ponby. iod..& .... , blood Iou.~";"" and maJ.boo.pri.. d;oo.d .... ...,...;"", , .... ..; • ...d ,",co_ oionalIy t.;[uu. n.;, "'" hod """;"",0. Iym. phoma .. ;th Mott cdla ...d "" !.ypoprot,;.",, ~ .... prohobly d", to naoItipl, p""""" • 2. Uri.., Moot .."" P""""" "" .. th. ~.p.b..I" ,.p.., ""' •• ,., ";!h ""em .... of ~ ~p d.alno. n.. Btoe< }..... .............. p...i", thz ; •• ....... .."'"",•• , .... .... iaIly d.u, fo.mo« •• ' '';1'' ...,., ocuuood, ,10. """"""""" ..... " .. tha, "" .Luk.. protrio baod .. th< .....p.. "",od th, ....... ~m d.&orn... of "" ,oadnt; ""'. H1P''I'rotrio=>< , ~ " ...,., d;[",od (mba I port """" to [ I"" ..I;., 0' ~ p..... ..u...) p