Evaluation of CD3+ T Cell Percentage, Function and its Relationship with Serum Vitamin D Levels in Women with Recurrent Spontaneous Abortion and Recurrent Implantation Failure

Women afflicted with recurrent spontaneous abortion (RSA) and repeated implantation failure (RIF) may have immune abnormalities. The role of vitamin D has been demonstrated in the function of the immune system. To assess the percentage and function of CD3+ T cells and their relationship with the level of the serum vitamin D or 1,25-dihydroxy vitamin D3 (the active form of the vitamin) in women with RSA and RIF. In this case-control study, peripheral blood was obtained from the patient and the healthy control groups. The ratio of CD3+T cell and activated CD3+ CD69+T cell was investigated using flow cytometry. The serum levels of Interferon-γ (IFN-γ) and vitamin D were measured by ELISA. The mean proportion of CD3+T cells in women with RSA increased significantly compared with the healthy control group (p<0.04). However, no significant difference was observed in RIF women compared with the control group. There was no significant difference in the ratio of activated CD3+CD69+T cells between the patient and the healthy control groups. Serum IFN-γ levels in women with RSA showed a significant increase compared to the control group (p<0.031); however, no significant difference was observed between women with RIF and the control group. Serum levels of vitamin D showed a significant reduction in both RSA (p<0.01) and RIF (p<0.04) groups in comparison with the control. An increase in the percentage and inflammatory function of T cells was associated with RSA. Decreased vitamin D levels may contribute to immune dysfunction and pregnancy loss.