Increased circulating paternal antigen-specific IFN-gamma- and IL-4-secreting cells during pregnancy in allergic and non-allergic women.

Introduction: Allergic women have been reported to give birth to more children than non-allergic women, speculatively explained by the former's predisposition for Th2 polarization, possibly favoring pregnancy.

Aim: The aim of this study was to test the hypothesis that allergy is associated with more Th2-deviated responses to paternal antigens throughout pregnancy.

Methods: Blood samples were collected on six occasions during pregnancy and two occasions postpartum (pp). Of the 86 women initially included, 54 women had a normal pregnancy and completed the sampling procedures. Eleven women fulfilled the strict criteria for allergy (allergic symptoms and circulating IgE antibodies to inhalant allergens) and 23 were strictly non-allergic (non-sensitized without symptoms). The numbers of blood mononuclear cells secreting IFN-gamma and IL-4, spontaneously and in response to paternal alloantigens, were compared between the groups.

Results: The numbers of spontaneously as well as paternal antigen-induced IFN-gamma- and IL-4-secreting cells were similar in allergic and non-allergic pregnant women on all occasions. A similar increase in the numbers of both IFN-gamma- and IL-4-secreting cells were found in allergic and non-allergic women during pregnancy, both regarding spontaneous and paternal antigen-induced secretion.

Conclusions: This study does not support the hypothesis of a more pronounced Th2-deviation to paternal antigens in allergic pregnant women compared with non-allergic pregnant women, as measured by number of cytokine-secreting cells. The observed increase of both IFN-gamma- and IL-4-secreting cells during normal pregnancy may be interpreted as a Th2-situation, since the effects of IL-4 predominate over the effects of IFN-gamma.