Validation of the Elecsys^® HIV combi PT assay for screening and reliable early detection of HIV-1 infection in Asia

Background: The Elecsys^® HIV combi PT assay was developed to allow earlier detection of HIV infection with increased sensitivity and specificity. Objectives: To validate the assay for screening and reliable early detection of HIV-1 infection in Asia. Study design: Samples tested reflected those routinely screened in Asia and comprised: HIV-1 antigen lysate (25 samples) and antibody (20 samples) dilutions; seven HIV-1 seroconversion panels (46 samples); 39 patient samples from early infection; 183 known-positive sera; HIV-1 p24 antigen sensitivity panel (seven samples); >500 routine clinical samples per center. The Elecsys^® HIV combi PT assay was compared with fourth- (ADVIA Centaur^® HIV combo, ARCHITECT^® HIV combo, Elecsys^® HIV combi) and third-generation (VIRONOSTIKA^® HIV Uni-Form II Plus O, Zhuhai Livzon Anti-HIV EIA, Serodia^® Particle Agglutination) assays commonly used in the region. Results: Overall, the Elecsys^® HIV combi PT showed superior or similar sensitivity to the comparators for detecting all subtypes. The assay correctly identified all positive samples, including those taken soon after infection, and detected seroconversion at a similar or shorter time interval than the comparators. The analytical sensitivity of Elecsys^® HIV combi PT for HIV-1 p24 antigen was 0.90IU/mL, which was lower than reported previously. The assay showed good specificity (99.86%) that was superior or equivalent to the other fourth-generation assays tested. Conclusions: These robust data demonstrate the good subtype inclusivity of the Elecsys^® HIV combi PT assay and its suitability for screening and reliable early detection of HIV infection in Asia.