Alteration of Th17 and Foxp3⁺ regulatory T cells in patients with unexplained recurrent spontaneous abortion before and after the therapy of hCG combined with immunoglobulin

We conducted this study to investigate the effects of the combination therapy of human chorionic gonadotropin (hCG) plus immunoglobulin (IG) on the levels of T helper 17 (Th17) cells and Foxp3⁺ regulatory T cells (Treg) in patients with unexplained recurrent spontaneous abortion (URSA). Twenty pregnant women with URSA underwent combination therapy of hCG plus IG. Flow cytometry was performed to measure the proportions of Th17 and Treg cells before and after treatment. RT-PCR and ELISA were applied to detect the concentrations of interleukin (IL)-17, IL-6, IL-10, and transforming growth factor (TGF)-β₁ in the peripheral blood. The therapy of hCG combined with IG may induce a decrease in the Th17/Treg ratio and the Treg bias, which may be beneficial for the maintenance of pregnancy. The levels of Th17 cells and related cytokines IL-17 and IL-6 decreased after the treatment (P<0.05). At the same time, levels of Treg cells and the related cytokines IL-10 and TGF-β₁ increased (P<0.05). The Th17/Treg ratio decreased significantly after treatment. In conclusion, the occurrence of URSA may be associated with the Th17/Treg balance disorder, and correcting the disorder may be one of the mechanisms behind the efficacy of combination therapy for URSA.