Increased numbers of circulating interferon-gamma- and interleukin-4-secreting cells during normal pregnancy

Abstract

Problem: Systemic immune responses during normal pregnancy are suggested to deviate toward secretion of T helper (Th)2-like cytokines.

Method of study: Blood samples from 11 healthy primigravidae in their first, second, and third trimesters, and 8 weeks postpartum were examined. Peripheral blood mononuclear cells were separated and the numbers of interferon (IFN)-gamma- and interleukin (IL)-4-secreting cells were identified by using the enzyme-linked immunospot test.

Results: In all three trimesters of pregnancy, and also postpartum, the numbers of IFN-gamma- and IL-4-secreting cells were significantly higher compared with nonpregnant controls (Mann-Whitney; P < 0.001). The numbers of IFN-gamma- and IL-4-secreting cells gradually increased as the pregnancy progressed compared with postpartum (Kruskas-Wallis; P < 0.01 and P < 0.05, for IFN-gamma and IL-4, respectively). The ratios of IFN-gamma/IL-4 during pregnancy and postpartum were unchanged, and also when compared with nonpregnant controls.

Conclusion: The results indicate a systemic up-regulation of both Th1- and Th2-like immune responses during normal pregnancy.