Valutazione di un test per la determinazione simultanea degli anticorpi e antigene p24 dell’HIV

A fourth generation immunoassay for the detection of antibodies to HIV-1 and HIV-2 and of HIV antigen p24 (Abbott Architect HIV Ag/Ab Combo) has been evaluated in comparison with two Ab-only third generation assays on 894 routine specimens and on preselected repository specimens.The Combo assay showed a better specificity (99.88% vs. 99.43-99.83%) and an analytical sensitivity for p24 of 22 pg/mL on a BBI commercial panel. The Architect assays gave a negative result on 22/24 repository false positive specimens from 18 subjects and, conversely, was positive on all the 39 repository specimens from 24 HIV-positive patients. On six patients with acute HIV infection the Architect assay gave an earlier positivity than the antibody-only assays (EIA and WB) on three cases, all viremic and positive for HIV p24.The performance characteristics of the new HIV Combo assay guarantee an advanced clinical sensitivity and a high specificity.