Specific IgA detection can be used for perinatal diagnosis of HIV in children under protocol ACTG 076.
Detection of anti-HIV-1 IgA antibodies using a modified ELISA test for the early diagnosis of perinatally acquired HIV-1 infection in children treated with protocol ACTG 076 was evaluated. A total of 177 sera were obtained from 141 infants between 1 and 12 months of age (46 were treated and 95 were non-treated with protocol ACTG 076) and tested for HIV IgA antibodies by an ELISA test after removal of IgG with recombinant protein G. Infants were classified according to CDC's classification system after a follow-up until 20 months of age. Of the 46 treated children 22 turned out to be infected and in the group of 95 untreated children, 52 were infected. All 81 samples from uninfected children treated or untreated with protocol ACTG 076 were persistently IgA-negative. HIV IgA antibodies were detected in 14 of 25 plasma samples from infected children with treatment, and in 58 of 71 samples in infected children without treatment. Considering that the sensitivity of this test is lower in children younger than 6 months the population of children studied was divided into two groups; those under and those over 6 months of age. No significant differences were observed in the detection of IgA in treated or untreated children in both age groups. The overall specificity of the test was 100 per cent; sensitivity in children older than 6 months was 76.92 per cent in treated children and 93.10 per cent in untreated children. In spite of the small number of samples studied it could be demonstrated that treatment with zidovudine does not affect the detection of IgA antibodies. This is a simple and inexpensive method that could be used for diagnosis of treated and untreated children in developing countries.