Modulations of cytokine expression in pregnant women

Problem: Although the overall anti-infectious and anti-parasitic immunity of parous women appears normal, several aspects of maternal cell-mediated and humoral immunity are altered during pregnancy. This has been suggested to occur via preferential local and systemic secretion of Th-2 type cytokines, which down-regulate or prevent secretion/action of Th-1 type cytokines, in animals as well as in humans. Method: To evaluate the influence of gestation on the maternal immune system, we have measured, in pregnant women, the mRNAs coding for several cytokines (TNFα, IFNγ, GMCSF, IL-1β, IL-2, IL-4, IL-6, and IL-10) in peripheral blood mononuclear cells, by use of semi-quantitative RT-PCR. Results: Our results show significant modulations of IFNγ, IL-1β, IL-4, and IL-6 genes expression especially during the third trimester and near parturition. Conclusion: Cytokine expression is thus finely tuned in peripheral blood during pregnancy, in a previously unexpected complex pattern, related to gestational stage.