Circulating cytokines and CD30 in normal human pregnancy and recurrent spontaneous abortions

Concentrations of the T-helper (Th) 1 cytokines interleukin (IL)-2, tumour necrosis factor (TNF)-alpha, TNF-beta and interferon-gamma, Th2 cytokines I L-4, IL-5, IL-6, IL-10 as well as those of soluble CD30 in sera have been e xamined during the three trimesters of gestation, at delivery in normal pre gnancy, and at the time of spontaneous abortion in women with a history of unexplained recurrent spontaneous abortion (RSA), Significantly higher conc entrations of the Th2 cytokines IL-6 and IL-10 were found at normal deliver y than in women with RSA, and conversely significantly increased concentrat ions of the Th1-type cytokine TNF-a were found in RSA as compared with succ essful pregnancy, In abortion-prone women who had a successful pregnancy, s ignificantly higher concentrations of IL-6 and significantly lower concentr ations of TNF-alpha were found as compared with abortion-prone women who ha d another abortion, supporting the notion that Th2- and Th1-bias are associ ated with successful and unsuccessful pregnancy respectively, Serum CD30 co ncentrations did not correlate with the outcome of pregnancy, These finding s support observations drawn from experiments on the cytokine secretion pro files of peripheral blood mononuclear cells and decidual lymphocytes which suggest that normal pregnancy is Th2-biased and that unexplained RSA is ass ociated with Th1-type reactivity.