Parasitic Infections in Pregnancy Decrease Placental Transfer of Anti-Pneumococcal Antibodies

Abstract

Many factors can influence maternal placental antibody transfer to the fetus, which confers important immune protection to the newborn infant. However, little is known about the effect of maternal parasitic infection on placental antibody transfer. To investigate this, we selected, from a parent study of 576 pregnant Kenyan women, four groups of women with term deliveries (≥37 weeks), including uninfected women (N=30) and women with solo infections of malaria (N=30), hookworm (N=30), or schistosomiasis (N=10). Maternal plasma at delivery and infant cord blood were tested via multiplex fluorescent bead assay for IgG against ten pneumococcal serotypes (PnPs 1, 4, 5, 6B, 7F, 9V, 14, 18C, 19F and 23F), diphtheria toxoid, and Haemophilus influenzae type B. Infants born to mothers with prenatal malaria, hookworm, or S. haematobium infections were associated with a significantly reduced ratio of maternal:infant cord blood antibody concentration for S. pneumoniae serotypes 1, 4, 5, 6B, 7F, 9V, and 18C compared to infants of uninfected mothers. Anti-diphtheria toxoid and anti-H. influenzae type B IgG ratios were not significantly different among infection groups. Prenatal parasitic infections decrease the transfer of maternal IgG antibodies to infants for several serotypes of S. pneumoniae.