Method: 123 samples, previously tested on the ARCHITECT i2000 analyser,were tested on the ALINITY system. Of these samples, 114 were selectedbasedonvarious ranges.Valuesbelow1.00S/CO(samplepercut-off )wereconsiderednon-reacPve,whilevaluesgreaterthan1.00S/COwereconsideredreacPve. All reacPve and discrepant results were confirmed using a thirdplaRorm(Vidasimmunoassayanalyser).

Findings:Fouroutof123samplestestedwereidenPfiedasdiscrepant.Thesewere analysed by VIDAS confirmatory tesPng and concurred with ALINITYresults(Table1).Fromthis,theALINITYmetthelaboratoryandmanufactureracceptance criteria (stated specificity of 99.89% (95%CI: 99.67% to 99.98%).AnalysisofEQANEQASHIVsamplesontheALINITYdidnotdeviatefromtheexpected results. The within-run and within-laboratory precision coefficientvariantpercentage (CV%)wasesPmatedusingALINITYQCposiPvematerials1,2 and 3 (Table 2). The analysis of the CV% revealed that the HIV tesPngperformed as reported by the manufacturer CV% (using the F staPsPcalanalysisdescribedbyForkmanJ(2009))andfoundthatbasedonaverage CV% of (5.56%) from the QC data for the ALINITY a measurement of 1 S/COcarries a Measurement of Uncertainty of (0.8888 to1.1112). A goodcorrelaPon was found between the ARCHITECT and the ALINITYmeasurements (R2=0.9926) (Figure 2). Bland-Altman analysis of theARCHITECTandtheALINITY(Figure3)showedaposiPvebias.Basedonthesefindings, the ALINITY HIV Ag/Ab Combo assay has met the laboratoryacceptance criteria for assay comparability with the Architect HIV Ag/AbCombomeasurements.

Conclusion:TheALINITYHIVAg/AbCombodemonstratedabeeersensiPvityandspecificity than the ARCHITECT and met the manufacturers and laboratoryacceptance criteria. In addiPon, its ease of use is anPcipated to have posiPveimplicaPons in meePng turnaround Pmes, subsequently enhancing the qualityand efficiency of the service. Overall the ALINITY HIV Ab/Ag Combo assay isconsideredfitforpurposeandreadyforfuturediagnosPcuse.

Introduc@on: The ARCHITECT i2000 and the ALINITY i HIV Ag/Ab Comboassaysarebasedonatwo-stepchemiluminescentmicroparPcleimmunoassay(CMIA) principle, for the simultaneous qualitaPve detecPon of HIV p24anPgenandanPbodiestohumanimmunodeficiencyvirustype1and/ortype2 (HIV-1/HIV-2) in human serum or plasma (Figure 1). The objec@ve is tocompareandvalidatetheperformanceofthenewAbboeALINITYiHIVAg/AbCombo assay against the current ARCHITECT i2000 HIV Ag/Ab Combo bystaPsPcally analysing the data collected from running paPent samples, kitcontrols,in-housecontrolsandexternalqualityassessment(EQA)samples.

Architect Alinity NonreacPve ReacPve GrandTotal

Nonreac@ve 24 4* 28Reac@ve 0 95 95

GrandTotal 24 99 123

ALINITY vs. ARCHITECT

AMANI ELHOUDERI, YVONNE OBIAJULU& PANAGIOTIS PANTELIDIS North West London Pathology, Charing Cross Hospital, Infection and Immunity Department, London, W6 8RF

Table 1: Alinity vs Architect raw data comparison. *Four samples idenPfied as discrepant. FollowingVIDASresoluPonofdiscrepantresultstheAlinityiHIVspecificitywas100%againsttheArchitect/VIDASresult.ThisshowstheALINITYmetthelaboratoryandmanufactureracceptancecriteria(statedspecificityof99.89%(95%CI:99.67%to99.98%).

Figure2:AnalysisofcorrelaPonbetweenS/COmeasurementsindicategoodcorrelaPonbetweenArchitectmeasurementsandtheALINITYiwithR2valueof0.9926.

Acknowledgements:DrAlisonCox(InfecPonandImmunityLaboratoryManager)forsourcingtheEQAmaterial,GrahamPickard(SeniorBiomedicalScienPst)forfilling change process forms and Abboe DiagnosPcs for providing kits free ofcharge.

Figure3:Bland-AltmananalysisofARCHITECTandALINITYiS/COmeasurementsshowedaposiPvebiasThetwoanalysersshowgoodagreementinmeasuringthesameparameter(HIVAb/AgComboassay).

Figure1:ChemiluminescentmicroparPcleimmunoassay(CMIA)principleandcomponentsforthequalitaPvedetecPonofanPgenandanPbodiestoHIV-1andHIV-2inhumanserumorplasma.

References:1.  CinquantaL(2017),Chemiluminescentimmunoassaytechnology:whatdoesitchangein

autoanPbodydetecPon?,h#ps://link.springer.com/ar4cle/10.1007/s13317-017-0097-2accessed12/03/2019

2.  ForkmanJ(2009)EsPmatorandtestsforcommoncoefficientsofvariaPoninnormaldistribuPons.CommunicaPonsinStaPsPcs-TheoryandMethods,usingonlineMEDCALCheps://www.medcalc.org/calc/comparison_of_coefficientsofvariaPon.php,accessed20/09/2018

Table2:StaPsPcalanalysisofthemanufacturersreportedprecisionCV%andtheobservedverificaPonprecisionCV%usingtheAlinityiHIVComboposiPvekitcontrols1,2and3.

Architecti2000Alinityi

Immunology/Virology