Comparison of the Percentages of Peripheral Blood CD4+ CD25+ T Lymphocytes in Recurrent Abortion and Normal Pregnancy

Background & Aims: Recent evidences indicate that parts of the immunoregulation system such as CD4+CD25+Tcells (Treg) and Th2 cells and Th1 cells, play very important roles in the maintenance of pregnancy. The deficiency in proper recognition of fetal alloantigen by the maternal immune system is associated with recurrent pregnancy failure. Here, we investigate the proportional changes of CD4+CD25+Tcells in peripheral blood of women with unexplained recurrent spontaneous abortion in comparison to women with normal pregnancy by using flowcytometry. Methods: The case group was comprised of 24 women who had at least three successive miscarriages with unexplained etiology. They had normal karyotypes, anticardiolipin and prolactin and their husbands had normal spermograms. The percentages of TCD4+CD25+cells in peripheral blood of these patients were compared with those of 21 women who had normal pregnancy with no history of pregnancy loss. Anti-CD4, anti-CD25 and anti-CD3 antibodies were added to lymphocytes isolated from peripheral blood. Then samples were incubated, centrifuged and washed. Finally cells were analyzed using FACS Caliber system and data of the two groups were compared. Results: Mean percentage of CD4+CD25+bright T cells in peripheral blood in case group was significantly lower compared to the control group (P=0.000). Mean percentage of CD4-CD25 bright cells in the CD4+Tcell peripheral blood was significantly higher in case group campared to the control group (P=0.021). Conclusion: Decrease of CD4+CD25 bright T cells plays a major role in tolerating conceptus antigens and cytokine and might contribute to the maintenance of pregnancy. Inadequate CD4+CD25+Tcells or their functional deficiency may link with miscarriage. Therefore, alteration of CD4+CD25+T cells can be used as an immunologic marker for monitoring of patients with unexplained recurrent spontaneous abortion.