Association of in utero sensitization to Schistosoma haematobium with enhanced cord blood IgE and increased frequencies of CD5- B cells in African newborns

Abstract

This study investigated in utero priming as a consequence of maternal parasitic infections. Cord blood plasma samples of 63 African newborns were assessed by enzyme-linked immunosorbent assay for their content of total and schistosome-specific or filaria-specific IgE and IgG4. The frequencies of lymphocyte phenotypes in cord blood were also determined by using flow cytometry, and were compared with those of European newborns. We found significantly increased schistosome soluble egg antigen (SEA)-specific IgE in cord plasma of those born to mothers with schistosome infections and correlations between fetal and maternal SEA-specific and filaria antigen-specific IgE. These data are evidence for in utero priming of the fetal immune system to maternal helminth infections. Furthermore, we show significantly enhanced percentages of CD5- B cells in African newborns cord blood compared with Europeans, which is consistent with earlier maturation of the African fetal immune system.

Figure 1.

Absolute values of IgE in 48 persons in Gabon. A, Absolute values of total (♦) and adult worm antigen (AWA)–specific (□) IgE (ng/mL and arbitrary units [AU], respectively) are significantly higher in maternal peripheral blood than in cord blood without a correlation between the two groups. B, Absolute values of Brugia malayi antigen (BmA)– (ο) and soluble egg antigen (SEA)–specific (Δ) IgE are significantly higher in maternal peripheral blood than in cord blood, but are positively correlated between the two groups. C, Absolute values of BmA– (ο), SEA– (Δ), and AWA-specific (□) IgG4 are nearly identical in cord and the respective maternal peripheral blood.

Figure 2.

Levels of Soluble egg antigen (SEA)–specific IgE are significantly higher in cord and maternal peripheral blood of Gabonese women depending on the presence of maternal schistosome infections (indicated as positive [pos.], n = 8, or negative (neg.), n = 40). Box-whisker plots illustrate medians with 25th and 75th percentiles and whiskers for 10th and 90th percentiles; P values are for Mann-Whitney U tests.

Figure 3.

Percentages of CD5– B-cells (of all B cells) are significantly higher in Gabonese newborns than in Dutch newborns (n = 15), but not in adults (n = 13). Box-whisker plots illustrate medians with 25th and 75th percentiles and whiskers for 10th and 90th percentiles. P values are for Mann-Whitney U tests.