Viral studies of mothers with human immunodeficiency virus infection at delivery and their infants in the first 3 days of life

Abstract

Objective: We studied 49 mother-infant pairs for human immunodeficiency virus (HIV) (a) to assess the virological and immunological status of HIV-infected mothers at delivery and their infants within the first 3 days of the infant's life, and (b) to correlate these findings with eventual infection outcome in the infant.

Method: Maternal blood from women in labor and infant's blood within 3 days of life were tested for the titer of HIV immunoglobulin G (IgG) antibody, for presence of HIV by culture, for p24 antigen, for HIV DNA by polymerase chain reaction (PCR), and for absolute T-helper cell count (CD4).

Results: Eight infants were in the confirmed infected (CI) group, with a transmission rate of 21%. Thirty infants were in the confirmed uninfected (CU) group. In the mother, mean anti-HIV IgG titer was 1:2600 (CI group) and 1:3350 (CU group); in the infant, the mean titer was 1:3250 (CI group) and 1:2710 (CU group). Eighty-seven percent of the mothers were culture-positive in the CI group compared to 33% in the CU group (p = 0.005). Eighty-seven percent of CI infants were PCR-positive at birth; none was PCR-positive in the CU group (sensitivity = 87%; specificity = 100%). Sixty-two percent of CI infants were culture-positive at birth, whereas none was positive in the CU group (sensitivity = 62%; specificity = 100%). Of the uninfected infants, 23% were positive for p24 antigen at birth.

Conclusions: HIV IgG antibody titers in mothers and their infants at birth were markedly elevated in both CI and CU groups but were not protective against infection. However, the high titers explain the long duration of this antibody in the blood of infants born to infected mothers. Culture positivity in the mother at delivery correlated highly with eventual infection in the infant (p = 0.005). HIV antigen, specifically p24 antigen, was detectable in uninfected infants when tested at birth.