Unexplained Recurrent Spontaneous Abortion And Th1/th2 Cytokines

Objective To investigate the function of Th1 and Th2 cytokine balance in the pathogenesis of unexplained recurrent spontaneous abortion (URSA).Methods Study group inclued 32 women with URSA and 20 reproductively normal parous coutrol women. Levels of interferon -gamma(IFN-() (the cytokine of Th1 ) and interleukin-4(IL-4) (the cytokine of Th2)in the supernatants of peripheral blood mononuclear cells (PBMC) cultured and stimulated with phytohaelmagglutinin(PHA) in vitro were determined by using enzyme linked immunoabsorbent assay (ELISA ). Results Level of Th1 cytokine IFN-( in supernatants of cultured PBMC in URSA patient was higher than those in normal controls (p<0.01),whereas level of Th2 cytokine IL-4 was lower(p<0.01).The ratio of IFN-( to IL-4 was enhanced in study groups than that in control groups(p<0.01).Conclusions During gestation, the immune system is changed.Th2-type immunity may be a natural response to trophoblast contributing to successful pregnancy. Th1-type immunity to trophoblast is associated with URSA and may play a role in reproductive failure, characterized by increased production of the cytokines IFN-(. A shift towards Th1 polarization of Th1/Th2 balance might explain pregnancy outcome.