PREDICTING PERINATAL HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION BY ANTIBODY PATTERNS

The evolution of human immunodeficiency virus type 1 (HIV-1) antibody titers determined by enzyme-linked immunosorbent assay between birth a nd 18 months of age was investigated in 118 babies born to HN-l-seropo sitive South African mothers. By 18 months 41 (34.7%) children were di agnosed as HIV-1-infected by standard criteria. All 77 uninfected babi es cleared maternal antibodies by 15 months; 94.5% of these babies ser oreverted by 12 months, By 9 months of age a significant difference (P < 0.05) was noted between antibody decay rates in infected and uninfe cted children. Of the children subsequently shown to be uninfected, 95 .8% demonstrated greater than or equal to 50% decay in antibody titers between 6 and 9 months; only 1 in the infected group showed a similar pattern (sensitivity, 97.8%; specificity 93.8%). The approach of asse ssing the progression of antibody decay in infected and uninfected bab ies makes it a feasible and useful tool for estimating vertical transm ission rates and diagnosis of perinatal HIV-1 infection earlier than s tandard practice.