Polymerase chain reaction, virus isolation and antigen assay in HIV-1-antibody-positive mothers and their children

Diagnosis of perinatal HIV-1 infection is complicated by the persistence of maternal antibodies and the conflicting reports on polymerase chain reaction (PCR) reactivity in children born to HIV-1-seropositive mothers. We have compared PCR with other diagnostic methods for perinatal HIV-1 infection and have attempted also to identify maternal markers which correlate with risk of transmission. PCR was the most sensitive method for early diagnosis of perinatal transmission of HIV-1, but the PCR-positive children (n = 11) developed at least one additional sign of infection. The PCR-negative children (n = 76) were clinically healthy, virus isolation negative, and their serum was HIV-1-antigen-negative. All children who had become seronegative (n = 36) were both PCR- and isolation-negative. Antigenaemia in the mothers correlated significantly with higher risk of perinatal transmission of HIV-1, while no other parameters (clinical stage, lymphocyte subsets, PCR and isolation) showed such a correlation. This indicates that the level of virus expression may be of key importance for the risk of vertical transmission of HIV-1 infection.