Soluble costimulatory molecule sTim3 regulates the differentiation of Th1 and Th2 in patients with unexplained recurrent spontaneous abortion

This study is to investigate the mechanism of unexplained recurrent spontaneous abortion (URSA). A total of 35 cases of URSA patients (URSA group), 20 cases with normal pregnancy (normal pregnancy group) and 20 healthy non-pregnancy candidates (healthy control group) were enrolled in this study. Enzyme linked immunosorbent assay (ELISA) method was used for detection of serum soluble Tim-3 (sTim3) and Galectin-9. Cytokine bead array (CBA) determination method was used to detect IFN-gamma and IL-4 expression levels. Compared with the healthy control group, sTim-3 levels in normal pregnancy group and URSA group increased, and URSA group had significantly higher sTim-3 levels than normal pregnancy group (P < 0.05). Compared with the healthy control group, Galectin-9 levels in normal pregnancy group and URSA group also increased. However, the normal pregnancy group had significantly higher Galectin-9 level than URSA group (P < 0.05). IFN-gamma levels in normal pregnancy group and URSA group were lower than those in healthy control group, and IFN-gamma levels in the normal pregnancy group were significantly lower than those in URSA group (P < 0.05). Levels of IL-4 in normal pregnancy group and URSA groups increased compared with the healthy control group, and the IL-4 levels in normal pregnancy group were significantly higher than those in URSA group (P < 0.05). Th1/Th2 imbalance, sTim-3 and Galectin-9 expression increase are found in the patients with URSA, ant this might be involved in the regulation of immunity in pregnancy.