Changes and clinical significance of peripheral blood helper T lymphocyte and natural killer (NK) cells in unexplained recurrent spontaneous abortion (URSA) patients after abortion and successful pregnancy

This study aims to investigate the number changes and the clinical significance of the peripheral blood T lymphocyte subsets and NK (natural killer) cells in unexplained recurrent spontaneous abortion (URSA) patients before and after abortion, as well as after successful pregnancy.Thirty-nine URSA patients (URSA-abortion group), among who 22 patients were followed up until the final successful parturition (URSA-pregnancy group), 31 normal-pregnancy (NP) cases and 25 normal non-pregnancy (NNP) control cases in which the peripheral blood T lymphocytes and subsets, B cells, and NK cells were assessed flow cytometry.Compared with the URSA-pregnancy group and the NP group, the Th cells and NK cells of the URSA-abortion group increased (p < 0.05); compared with the NNP group, the total number of T cells decreased after the first, second, and third month of the URSA abortion (p < 0.05); Th cells decreased within one to six months of the URSA abortion (p < 0.05); proportion of NK cells was significantly higher in URSA patients (p < 0.05).The abnormal numbers of the peripheral blood T cell subsets and NK cells were related with the occurrence of URSA.