Comparison of enzyme immunoassay and reverse transcriptase assay for detection of HIV in culture supernates.

An enzyme immunoassay (EIA) was developed for detection of human immunodeficiency virus antigen (HIV Ag) in tissue culture supernatants. The assay was found to be specific for HIV and cheaper, easier to perform and more sensitive than the generally used reverse transcriptase (RT) assay. Cultures of peripheral blood leucocytes (PBL) from 106 patients with acquired immune deficiency syndrome (AIDS), AIDS related complex (ARC), healthy anti-HIV positive subjects and healthy anti-HIV negative subjects were held for 35 days and the supernatant fluid tested at regular intervals by EIA and RT. Of these 106 cultures, the presence of HIV was detected by EIA in 27 and by RT in 21. While six cultures were positive by EIA alone, none were positive by RT alone; the specificity of the results in the six EIA positive RT negative cultures was confirmed by subculture. In the 21 cultures in which HIV was detected by both techniques, the EIA became positive first on 10 occasions; in the remaining cultures both tests became positive at the same time. The HIV Ag assay reduces the time taken to process specimens and thus increases the efficiency and reduces the cost of isolation procedures.