Human immunodeficiency virus type 1 p24 production and antigenic variation in tissue culture of isolates with various growth characteristics.

Two monoclonal antibodies (Mabs) reacting with different epitopes of the human immunodeficiency virus type 1 core protein p24 (HIV p24) were used either singly or in combination as tracers in enzyme-linked immunosorbent assays. The culture supernatant of 215 samples of peripheral blood mononuclear cells from 112 patients were measured for HIV p24 and reverse transcriptase (RT) activity during cultivation. One hundred forty-one cultures were positive for HIV p24 and 122 for RT after 32 days of cultivation. After 8-9 days, HIV p24 was detected in 50.4% and RT in 27.8% of the cultures later judged as HIV positive. Two patients seemed to have substrains of HIV-1 not reactive with one of the Mabs.