Reduced maternal regulatory T cell numbers and increased T helper type 2 cytokine production are associated with elevated levels of immunoglobulin E in cord blood.

BACKGROUND

There is evidence that the basis of an atopic-skewed immune response is acquired early in life, perhaps at the fetal stage. Thus, we hypothesized that the development of the fetal immune system might be influenced by maternal regulatory T cells (Treg) and maternal T cell cytokine production during pregnancy. The aim of the present study was to assess the influence of maternal Treg and cytokine production during pregnancy on Treg and atopy at birth.

METHODS

Within the mother-child study LINA (Lifestyle and Environmental factors and their Influence on Newborns Allergy risk), we determined the frequency and function of Treg and the total IgE concentration in pregnant women in the 34th week of gestation and in corresponding cord bloods at birth (n=24). Furthermore, we assessed how maternal mitogen-induced T-helper type 1/T-helper type 2 and inflammatory cytokines influence the level of cord blood Treg and IgE.

RESULTS

Frequencies of CD4(+)CD25(high) T cells were higher (P=0.001), whereas percentages of FOXP3+ T cells were lower (P<0.001) in cord blood cells compared with maternal blood. Reduced maternal CD4(+)CD25(high) Treg frequencies correlated with increased total IgE concentrations at the 34th week of gestation (r=-0.32, P=0.028) and with increased IgE concentrations in cord blood (r=-0.50, P<0.001). Elevated maternal mitogen-induced Th2 cytokine production was related to increased total IgE levels in the serum of corresponding cord bloods (IL-4, r=0.53; IL-5, r=0.43; IL-13, r=0.52).

CONCLUSIONS

Because cord blood IgE has been shown to be predictive for allergic diseases in early childhood, our results indicate that reduced maternal Treg numbers and increased Th2 cytokine production during pregnancy might influence the allergy risk of the child.