RETROCELL HIV-1 passive hemagglutination assay for HIV-1 antibody screening

A passive hemagglutination assay (PHA) for serum human immunodeficiency virus type 1 (HIV-1) antibody screening was developed using aldehyde-stabilized human erythrocytes coated with purified HIV-1 antigens. The assay is simple to perform, and the components are inexpensive. In preliminary testing of a panel of 490 confirmed HIV-1 seropositive specimens, all tested positive by the HIV-1 PHA assay. By testing seroconversion specimens and dilution panels, the assay demonstrated a sensitivity equivalent to a recombinant protein-based HIV-1 enzyme immunoassay (EIA). In-house evaluation of 2,557 HIV-1 prescreened specimens from South African blood bank donors revealed initial and repeat reactive rates of 0.2 and 0.04%, respectively. Field testing of the HIV-1 antibody PHA at two sites gave performance of 100% sensitivity (400 seroconfirmed samples) and 0.55% initial/0.28% repeat reactive rates in the testing of 3,983 negative samples. The performance, low cost, and ease of use make the HIV-1 antibody PHA test a prime candidate for HIV-1 antibody screening in regions of the world where more sophisticated technology is inappropriate.