Comparative evaluation of three FDA-approved HIV Ag/Ab combination tests using a genetically diverse HIV panel and diagnostic specimens

•Performance of ARCHITECT, Centaur and BioPlex HIV Ag/Ab tests was evaluated.•BioPlex and ARCHITECT assays showed sensitive detection in acute HIV-infection.•The ARCHITECT assay had most sensitive detection across divergent HIV-1 genotypes.•The ARCHITECT assay demonstrated the highest clinical specificity.

BackgroundHIV Ag/Ab combination assays are recommended by CDC for routine screening and several HIV Ag/Ab combination tests are now FDA-approved. Maintaining high specificity and consistent sensitivity across diverse HIV strains is critical for these assays to accurately detect HIV infection and expedite delivery of patient results.ObjectivesTo evaluate performance of three FDA-approved HIV tests: ARCHITECT HIV Combo (Abbott), ADVIA Centaur HIV Combo (Siemens) and BioPlex HIV Ag-Ab (Bio-Rad).Study designSensitivity and specificity were evaluated using an extensive panel of 28 HIV infected human specimens and 17 cultured virus isolates representing multiple genotypes, 6 seroconversion panels, 4 human samples with acute infection, WHO p24 standard and 4020 clinical specimens.ResultsThe p24 limit of detection (LOD) for the WHO standard was 0.19 IU/ml, 0.70 IU/ml, and 1.77 IU/ml in BioPlex, ARCHITECT, and Centaur respectively. The distribution of LODs across 15 HIV-1 isolates was substantially narrower in ARCHITECT (5-33 pg/ml) than in BioPlex (11-198 pg/ml) and Centaur (6-384 pg/ml). All assays detected antibodies to the majority of HIV-1 and HIV-2 variants. However, reduced sensitivity was observed for Centaur in detection of antibodies to HIV-1 group M (CRF02_AG), O and N variants. BioPlex and ARCHITECT showed better seroconversion sensitivity than Centaur, detecting one bleed (3-7 days) earlier in 4 (BioPlex) and 3 (ARCHITECT) of 6 seroconversion panels. ARCHITECT demonstrated the highest specificity (99.90-100%) compared to BioPlex (99.80%) and Centaur (99.42%).ConclusionsThe overall performance of ARCHITECT and BioPlex was superior to Centaur, especially for detection of acute HIV infection.