Background: 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.
Objective: 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.
Methods: 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.
Results: 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.
Conclusion: 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.
Keywords: Interferon-γ; Recurrent Implantation Failure; Recurrent Spontaneous Abortion; T-Cells; Vitamin D.