Maternal HIV-1 antibody and vertical transmission in subtype C virus infection.

The role of maternal humoral immune response and viral load was analyzed in relation to the incidence of mother-to-child transmission (MTCT) of infants born to HIV-1 subtype C infected mothers. High levels of viral RNA in the serum correlated with MTCT as did high titers of subtype C consensus V3 peptide binding antibodies (BA) and neutralizing antibody (NA) to subtype B HIV-1MN. Logistic regression analysis showed that maternal viral load and V3 peptide subtype C BA were independent predictors for MTCT, odds ratio (OR) = 2.22 and OR = 2.52, respectively. No correlation between NA to homologous HIV-1 subtype C virus and MTCT was found. BA to V3 peptides may provide a rapid inexpensive method that can be used to determine the risk of HIV-1 MTCT.