DETECTION OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 (HIV-1) ANTIBODY BY WESTERN BLOTTING AND HIV-1 DNA BY PCR IN PATIENTS WITH AIDS

The human immunodeficiency virus type 1 (HIV-1) Western blotting (immu noblotting) band patterns and the sensitivity of an HIV-1 DNA PCR assa y were determined by testing the blood of patients with AIDS. Plasma a nd cell pellets processed from the peripheral blood of 199 patients wi th absolute CD4 cell counts of less than 200 cells per mm(3) were test ed by a licensed enzyme immunoassay (EIA; Abbott HIV-1) and Western bl ot assay (Cambridge-Biotech) for HIV-1 antibody. The Roche HIV-1 AMPLI COR DNA PCR assay was used to test cell pellets from 125 of the 199 pa tients for HIV-1 gag DNA sequences. All plasma samples from these 199 sequential patients were reactive for HIV-1 antibody by EIA and were p ositive by Western blot assay using the criteria recommended by the Ce nters for Disease Control and Prevention. The majority of samples (192 of 199; 96.5%) displayed at least six of nine bands characteristic of the virus by Western blotting, with the lowest number of bands charac teristic of the virus displayed by any sample being three. However, 39 and 48% of all patients exhibited no bands to p17 and p55 antigens, r espectively, whereas 0 to 7.5% of all patients exhibited no bands to t he other antigens. HIV-1 gag DNA sequences were detected in 117 (93.6% ) of 125 cell pellets processed from the peripheral blood of these sam e patients. All eight patients initially negative by PCR tested positi ve when a second pellet which had been produced from the same blood sa mple was tested. Despite a decrease in antibody reactivity to HIV Gag and Pol proteins, patients with advanced HIV-1 infection remained posi tive for HIV-1 antibody by EIA and Western blot testing. Confirmation by the HIV-1 Western blot assay still appears to be the more sensitive assay for the diagnosis of HIV-1 infection in those individuals with advanced HIV-1 infection in the United States.