Rev. Bras. Hematol. Hemoter. vol.37 número1

rev bras hematol hemoter. 2015;37(1):69–70

Revista

Brasileira

de

Hematologia

e

Hemoterapia

Brazilian

Journal

of

Hematology

and

Hemotherapy

w w w . r b h h . o r g

Letter

to

the

Editor

To

follow

or

not

to

follow

the

recommendations

regarding

microscopic

analysis

of

the

Clinical

and

Laboratory

Standards

Institute

H20-A2

to

validate

the

criteria

for

blood

smear

review?

DearEditor,

WereadwithgreatinteresttheLettertotheEditorbyGrotto1

ontheneedtofollowtheClinicalandLaboratoryStandards Institute2007H20-A22_{guidelinesduringmicroscopic}

analy-sisinreplytothestudybyComaretal.3 _{Weappreciatethe}

commentsthatensuredextensivediscussiononthissubject. Thework ofBarnesetal.,4 _{whichrepresentsthecoreof}

the criteriaforblood smear review(BSR)recommended by theInternational SocietyforLaboratoryHematology (ISLH), emanatesfromaninternationalconsensusamong20experts in 2002 during a conference in Indian Wells, CA, USA. In consensus,Barnesetal.4 _{proposedanine-stepprotocol for}

validatingtheBSRcriteriainroutinelaboratorypractices.Step 4ofthisprotocolisasfollows:“Performaslidereviewofall samples.Limitthereviewstoonlyoneortwosenior tech-nologistsforconsistency.Manualdifferentialsshouldonlybe performedifthereisaspecificneedtodoso(e.g.,Voteout, abnormalcell-typeflags,etc.)”

Thestep-wiseprotocolbyBarnesetal.4_{doesnotmention}

theNCCLSH20-A5_{asasinequanonconditionforthe}

micro-scopicreviewofbloodsmears.Intheirwork,Barnesetal.4_did

notmandatetheapplicationoftheNCCLSH20-A5_guidelines,

asinterpretedbyGrotto.1_{Thus,Barnesetal.}4_{didnotexclude}

thepossibilityofoneobservercounting100cellstovalidate theBSRcriteria.Wethereforeunderstandthatcounting per-formedbyeitheroneortwoobserversisequallyacceptable.

TheCLSIH20-A22_{(formerlyNCCLSH20-A)}5_isareference

document to evaluate hematology analyzers that perform automated leukocyte differential counts and consider the visualleukocytedifferentialcountasthegoldstandard.Most studies that rigorously followed this guideline specifically evaluatedtheautomatedleukocytedifferentialcountandthe suspectflags ofthe hematology analyzers.6,7 _{On the other}

hand,studiesevaluatingsetsofcriteriaforBSRdidnot nec-essarilyfollowtherecommendationsoftheNCCLSH20-A5_or

CLSIH20-A22_{regardingthemicroscopicanalysis.}4,8–11_Thus,

weemphasizethat,inthestudyofComaretal.3_thestep-wise

rulesofBarnesetal.4_{thatexclusivelydealwiththevalidation}

oftheBSRcriteriawerefollowed.

WebelievethatBarnesetal.4_{recommendedslidereviewby}

eitheroneortwoobservers,withoutspecifyingasetnumber ofslidespersamplenorthenumberofcellstobecountedper slide,toenableapplicationofthesameprotocolsofsample collectionandprocessingasinroutineprotocolsfor valida-tionpurpose,thussimulatingthereal-timeconditionsofmost hematologylaboratories.

WeevaluatedthecriteriaforBSRbyusingthehematology analyzersprovidedbySysmexCorporation.3_{Theapplication}

of the criteriafor BSR adaptedfrom ISLHresulted in high falsenegative(FN)(>5%)andmicroscopicreviewrates(MRR). SimilarresultswerereportedbyXingetal.12_inananalysis

of2400samplesusingtheADVIA120/2120hematology ana-lyzer,accordingtothescreeningcriteriaproposedbyISLHand theirown positivesmearfindings[FN=5.5%,falsepositives (FP)=28.1%,and MRR=50.2%]. Itisimportanttoemphasize that we did not conclude “the inadequate performanceof bothpiecesofequipment”inanyinstanceoftheproposals byComaretal.3_{Weexplainedthat30%oftheFPresults(i.e.,}

6.98%ofthetotalsamplesor138samplesin1977)occurred duetothepresenceofsuspectflagsinthesamples.This per-centagerepresentsthesumofallsuspectflagsgeneratedin allsamplesandwhosemicroscopiccounterpartdidnot pro-videanypositivesmearfinding.WebelievethattheFPrates observedbyComaret al.3_{canbepartiallyattributedtothe}

70

Inourexperience,inindividualanalysis,themainsuspect flagsdeliveredthefollowingresultsusingtheXE-2100D hema-tologyanalyzerforsamplessimilartothoseusedbyComar etal.3_{:TheFNrateandefficiencyforimmaturegranulocytes}

were1.15%and94.71%;theFNrateforblastswas0.17%(n=3 samples);andtheefficiency,sensitivity,andspecificityforLeft Shiftwere82.4%,44%,and92.08%,respectively.13_Therefore,

unlikeGrotto’s(1)interpretation,theperformancesofthese suspectflagswerealmostsimilartothosereportedby Stam-mingeretal.6_{andRuzickaetal.}14

Insummary,eachlaboratoryshouldestablishitsown cri-teriaforBSRofbloodcountsaccordingtotheirpeculiarities, possibilities,andlimitations,anditshouldfollowthe appro-priateguidelinesandtoolstovalidatesuchcriteriainroutine laboratorypractices.Afteracarefulanalysisoftheresults dis-cussedabove,weconcludethattheuseoftherulesproposed byBarnesetal.4_{wasadequateinthestudyofComaretal.}3

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

r

e

f

e

r

e

n

c

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s

1. GrottoHZ.Whyandhowvalidatethecriteriaformanual smearreviewforimprovingthelaboratoryproductivity?Rev BrasHematolHemoter.2014.thisissue.

2. ClinicalandLaboratoryStandardsInstitute(CLSI).Reference leukocyte(WBC)differentialcount(proportional)and evaluationofinstrumentmethods:approvedstandard.2nd ed.Wayne,PA:CLSI;2007.DocumentH20-A2.

3. ComarSR,MalvezziM,PasquiniR.Arethereviewcriteriafor automatedcompletebloodcountsoftheInternational SocietyofLaboratoryHematologysuitableforallhematology laboratories?RevBrasHematolHemoter.2014;36(3):219–25.

4. BarnesPW,McfaddenSL,MachinSJ,SimsonE.The internationalconsensusgroupforhematologyreview: suggestedcriteriaforactionfollowingautomatedCBCand WBCdifferentialanalysis.LabHematol.2005;11(2):83–90.

5. NationalCommitteeforClinicalLaboratoryStandards (NCCLS).Referenceleukocyte(WBC)differentialcount (proportional)andevaluationofinstrumentmethods: approvedstandard.Villanova,PA:NationalCommitteefor ClinicalLaboratoryStandards;1992.DocumentH20-A.

6. StammingerG,AuchD,DiemH,SinhaP.Performanceofthe XE-2100leukocytedifferential.ClinLabHaematol.

2002;24(5):271–80.

7.JonesRG,FaustA,GlazierJ,MatthewsR,PotterB.Cell-Dyn 4000:utilitywithinthecorelaboratorystructureand preliminarycomparisonofitsexpandeddifferentialwiththe 400-cellmanualdifferentialcount.LabHematol.1998;4:34–44.

8.ComarSR,MalvezziM,PasquiniR.Establishmentand evaluationofreviewcriteriaofautomatedcompleteblood countsapplyingreceiveroperatingcharacteristics(ROC) curveanalysis.IntJLabHematol.2013;35Suppl.1:44–5.

9.LantisKL,HarrisRJ,DavisG,RennerN,FinnWG.Elimination ofinstrument-drivenreflexmanualdifferentialleukocyte counts.Optimizationofmanualbloodsmearreviewcriteria inahigh-volumeautomatedhematologylaboratory.AmJ ClinPathol.2003;119(5):656–62.

10.PratumvinitB,WongkrajangP,ReesukumalK,KlinbuaC, NiamjoyP.Validationandoptimizationofcriteriaformanual smearreviewfollowingautomatedbloodcellanalysisina largeuniversityhospital.ArchPatholLabMed.

2013;137(3):408–14.

11.FroomP,HavisR,BarakM.Therateofmanualperipheral bloodsmearreviewsinoutpatients.ClinChemLabMed. 2009;47(11):1401–5.

12.XingY,WangJZ,PuCW,ShangK,YanZL,BaiWS,etal. EstablishmentandevaluationofreviewcriteriaforADVIA 120/2120anddifferentseriesofhematologyanalyzers. ZhonghuaYiXueZaZhi.2010;90(22):1526–30.

13.ComarSR,MalvezziM,PasquiniR.Theusefulnessofsuspect flagsontheSysmexXE-2100Dhematologyanalyzer.IntJLab Hematol.2014;36Suppl.1:110.

14.RuzickaK,VeitlM,Thalhammer-ScherrerR,SchwarzingerI. ThenewhematologyanalyserSysmexXE-2100Performance evaluationofanovelwhitebloodcelldifferentialtechnology. ArchPatholLabMed.2001;125(3):391–6.

SamuelRicardoComar∗_{,MariesterMalvezzi, Ricardo}

Pasquini

UniversidadeFederaldoParaná(UFPR),Curitiba,PR,Brazil

∗_{Correspondingauthorat:LaboratóriodeHematologia,Unidade}

deApoioDiagnóstico,HospitaldeClínicas,Universidade Fe-deraldoParaná(UFPR),RuaPadreCamargo,280,AltodaGlória, 80060-240Curitiba,PR,Brazil.

E-mailaddress:srcomar@ufpr.br(S.R.Comar).

Received19September2014 Accepted20September2014 Availableonline21November2014

http://dx.doi.org/10.1016/j.bjhh.2014.11.005