[An evaluation of the efficacy of different commercial kits in the serological diagnosis of the early phase of human immunodeficiency virus infection].

The aim of the present study was to identify the most useful serum markers for the early identification of the infection by the human immunodeficiency virus (HIV). To this end, sequential serum samples of 19 individuals who later had seroconversion to anti-HIV were evaluated. The p24 antigen (Ag-HIV) was the earliest marker of the infection, although it could only be detected in five of the 19 individuals: in two as an isolated marker and in the remaining four associated to anti-HIV (first generation Western blot: WB-1, and recombinant enzyme immunoanalysis: EIA-2G). In 12 of the 19 individuals, WB-1G (Pasteur) was the technique which permitted the earliest detection of anti-HIV: in five cases with bands which made the unequivocal diagnosis of the infection, and in seven with indeterminate results (anti-HIV against core or envelope antigens). The second earliest test was the detection of anti-HIV against envelope antigens with a competitive EIA-2G (Abbott). WB-1G (Sorin) detected anti-HIV in a late phase, as it was the case for EIA-1G or EIA-2G for anti-HIV against antigens encoded by the GAG gene. These results indicate that there may be remarkable differences in sensitivity among the different commercial kits. The use of EIA for Ag-HIV together with WB-1G shortens the gap period of HIV infection, even if seroconversion is identified with EIA-2G for global anti-HIV.