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

rev bras hematol hemoter. 2015;37(1):67–68

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

Why

and

how

validate

criteria

by

manual

smear

review

to

improve

laboratory

productivity?

DearEditor,

Ireadthearticle“Arethereviewcriteriaforautomated

com-pletebloodcountsoftheInternationalSocietyofLaboratory

Hematologysuitable forall hematologylaboratories?”,

pub-lishedinRBHH2014;36(2);219–225,1_{andIwouldliketomake}

somecommentsaboutit.

Thepurposeofthestudyisremarkableanditisknownthat

eachLaboratoryhastodefinetheirowncriteriaforreviewing

bloodsmears.Severalstudieshavereporteddifferent

expe-rienceswhenmanualmethodswerereplacedbyautomated

hematology systems, all ofwhich described improvements

in quality and precision, in addition to faster reportable

results.2–4_{Comaretal.appliedthereviewcriteriaofthe}

Inter-nationalSocietyforLaboratoryHematologyintheirstudywith

someadaptations according to local requirements.A total

of1977wholeblood sampleswere analyzedontwo pieces

ofequipment and 100leukocyteswere countedbyasingle

observer.Amongotherresults,theauthorsreportedhighrates

ofmicroscopyreviewsandanunacceptablepercentageoffalse

negativeresults(>5%).

Someconsiderationsshouldbementionedaboutthis

eval-uation. First,and mostimportantinmyview,isrelated to

microscopicanalysis.AccordingtotheNational Committee

forClinical LaboratoryStandards(NCCLS)document

‘Refer-enceLeukocyte(WBC)DifferentialCount,H20-A2’5_somerules

mustbefollowedinordertoobtainareliableanalysis,such

as:(i)threebloodfilmsfromeachspecimenshouldbe

pre-pared(twoareusedfortheprocedureandthethirdiskeptas

aspare);(ii)alargernumberofbloodfilmsmustbeprepared

forleukopenicsamples;(iii)200WBCshouldbecountedon

eachslide;and(iv)atleasttwoexaminersmustbeableto

clas-sifyallnormalandabnormalcells.Theserecommendations

werenotfollowedinthestudy,whichmayexplain,according

totheauthors,“theinadequateperformanceofbothpiecesof

equipment”.Otherstudies,usingtheNCCLSDocumentasan

evaluationprotocol,showeddifferentresults.Rusickaetal.6

testedtheefficiencyofflaggingusingtheXE-2100deviceand

showedthattherateoffalsenegativeresultsoftheimmature

granulocytecategorywasonly1%andtheefficiencyrateof

myeloidprecursorcelldetectionwas84%.Regardingthefalse

negativeresultsforblasts,theratewas1%(5samples),allof

themshowingleukocytecounts<2.5×109/L,andfourofthem

wereflaggedbytheatypicallymphflagorIGflag.Thismeans

that,althoughtheblastcellwasnotdetected,thebloodcell

smearshouldbeexaminedduetoadditionalflags. Another

study waspublishedbyStammingeretal.7 _{where800cells}

were analyzedpersample.Theauthorsconsideredthe Left

Shifttobepositiveifbandcellswere>0.9×109/Lor6%and/or

aneutrophilproportion>80%.TheefficiencyoftheLeftShift

flagwas0.86(sensitivity0.53andspecificity0.92).Whenthe

combination LeftShiftplusneutrophiliawasapplied,there

wasasignificantincreaseintheefficiency(0.92),sensitivity

(0.83)andspecificity(0.92).Consideringthevariationsin

mor-phologicaldefinitionofthebandcell,thecountofthiscellin

theroutinelaboratoryisapparentlyunreliable.

Insummary,theprogressofhematologyautomationand

theachievedgoodlevelsofprecisionandtheaccuracyincell

countingareincontestable.Theexaminationand

identifica-tionofthousandsofcellsineachsample,theimprovementin

technologiesandtheincorporationofnewparametersprovide

reliable and applicableinformationfordiagnosis inseveral

clinicalconditions.Automationwillmostlikelynevertotally

replacethemicroscopicreviewofbloodcells.The

examina-tion ofred cell morphology is crucial for the diagnosis of

anemia,andautomationdoesnotprovidealltheinformation

thatispotentiallyimportanttothephysician.8_Thepurpose

ofautomationistoprovidefasterreportableresults,toreduce

thetechnologisthands-ontime,inadditiontoprovidinghigh

qualityand precision.Eachlaboratorymustdefinethe best

criteriatoachievetheirperformancegoals.Severaltoolsand

guidelinesareavailabletoanalyzetheperformanceof

equip-ment,andtodefinethebestrulesforspecificneeds.

Conflicts

of

interest

Dr.HelenaGrottoisMedicalAdvisorofSysmexLatinAmerica

68

r

e

f

e

r

e

n

c

e

s

1.ComarSR,MalvezziM,PasquiniR.Arethereviewcriteriafor automatedcompletebloodcountsoftheInternationalSociety oflaboratoryHematologysuitableforallhematology

laboratories?RevBrasHematolHemoter.2014;36(3):219–25.

2.LantisKL,JayneHarrisR,DavisG,RennerN,FinnWG. Eliminationofinstrument-drivenreflexmanualdifferential leukocytecounts.AmJClinPathol.2003;119(5):656–62.

3.GuarnerJ,AtuanMA,NixB,MishakC,VejjajivaC,CurtisC, etal.Processtoevaluatehematologicalparametersthatreflex tomanualdifferentialcellcountsinapediatricinstitution. ClinLab.2010;56(1–2):21–7.

4.BriggsC,LinssenJ,LongairI,MachinSJ.Improvedflagging ratesontheSysmexXE-5000comparedwiththeXE-2100 reducethenumberofmanualfilmreviewsandincrease laboratoryproductivity.AmJClinPathol.2011;136(2):309–16.

5.NCCLSDocumentH-20-A2.Referenceleukocyte(WBC) differentialcount(proportional)andevaluationof

instrumentalmethods;approvedstandard-secondedition. CLSI.2007;27(4).

6.RuzickaK1,VeitlM,Thalhammer-ScherrerR,SchwarzingerI. ThenewhematologyanalyzerSysmexXE-2100:performance

evaluationofanovelwhitebloodcelldifferentialtechnology. ArchPatholLabMed.2001;125(3):391–6.

7.StammingerG,AuchD,DiemH,SinhaP.Performanceofthe XE-2100leucocytedifferential.ClinLabHaem.

2002;24(5):271–80.

8.FordJ.Redbloodcellmorphology.IntJLabHematol. 2013;35(3):351–7.

HelenaZerlottiWolfGrotto∗

SysmexLatinAmérica&TheCaribbean,SãoPaulo,SP,Brazil

∗_{Correspondenceto:RuadoParaíso,148,Cj.31,04103-000São}

Paulo,SP,Brazil.

E-mailaddress:[email protected]

Received28July2014

Accepted29September2014

Availableonline20November2014

http://dx.doi.org/10.1016/j.bjhh.2014.11.007

1516-8484/©2014Associac¸ãoBrasileiradeHematologia,

HemoterapiaeTerapiaCelular.PublishedbyElsevierEditora