Comparison of antigen assay and reverse transcriptase assay for detecting human immunodeficiency virus in culture

We compared an antigen capture assay (Abbott Laboratories, North Chicago, Ill.) with a reverse transcriptase assay to identify and quantify human immunodeficiency virus (HIV) in culture. In direct comparisons of serial dilutions of lymphadenopathy-associated virus type 1, the antigen assay was 100-fold more sensitive than the reverse transcriptase assay in detecting the virus. The antigen assay reacted strongly with 60 different HIV isolates but did not cross-react with human T-cell lymphotropic virus type I, human T-cell lymphotropic virus type II, cytomegalovirus, varicella-zoster virus, herpes simplex virus type 1, Epstein-Barr virus, adenovirus type 5, or poliovirus type 1 or with extracts from four different control human cell lines and eight different phytohemagglutinin-stimulated normal human lymphocytes. Peripheral blood lymphocyte samples from 50 individuals were evaluated by both the antigen assay and the reverse transcriptase assay. The cells from the 34 seropositive individuals were all positive by the antigen assay (range, 3 to 9 days; average time, 5.9 days) and the reverse transcriptase assay (range, 7 to 16 days; average time, 9.6 days). Cells from the 16 seronegative individuals were negative by both assays. These results indicate that the antigen assay is an important addition to the monitoring of HIV production in the lymphocytes of infected patients.