J Baharara - Assistant Professor, Biology Department, Mashhad Islamic Azad University, Mashhad, Iran
R Mozayani - Graduate of Cellular & Developmental Biology, Biology Department, Mashhad Islamic Azad University, Mashhad, Iran
N Mousavifar - Assistant Professor of Obstetrics & Gynecology, Women&#۰۳۹;s Health Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
A SHeikh - Immunology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
M Rastin - Immunologist, Immunology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
N Tabasi - Graduate of Animal Physiology, Immunology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
M.A Eslami - Medical Student, Zahedan University of Medical Sciences, chabahar Branch
A Eslami - Medical Student, Shaheed Beheshti University of Medical Sciences, Tehran, Iran
M Mahmodi - Professor of Immunology, Immunology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran

Background & Aims: Recent evidences indicate that parts of the immunoregulation system such as CD۴+CD۲۵+Tcells (Treg) and Th۲ cells and Th۱ 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 CD۴+CD۲۵+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 ۲۴ 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 TCD۴+CD۲۵+cells in peripheral blood of these patients were compared with those of ۲۱ women who had normal pregnancy with no history of pregnancy loss. Anti-CD۴, anti-CD۲۵ and anti-CD۳ 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 CD۴+CD۲۵+bright T cells in peripheral blood in case group was significantly lower compared to the control group (P=۰.۰۰۰). Mean percentage of CD۴-CD۲۵ bright cells in the CD۴+Tcell peripheral blood was significantly higher in case group campared to the control group (P=۰.۰۲۱). Conclusion: Decrease of CD۴+CD۲۵ bright T cells plays a major role in tolerating conceptus antigens and cytokine and might contribute to the maintenance of pregnancy. Inadequate CD۴+CD۲۵+Tcells or their functional deficiency may link with miscarriage. Therefore, alteration of CD۴+CD۲۵+T cells can be used as an immunologic marker for monitoring of patients with unexplained recurrent spontaneous abortion.

Recurrent abortion, CD۴+CD۲۵+ T cells, Flowcytometry