Changes of CD4+CD25high regulatory T cells and FOXP3 expression in unexplained recurrent spontaneous abortion patients

ObjectiveTo investigate the proportions of CD4+CD25high T cells and forkhead box p3 (FOXP3) expression in peripheral blood and decidua in patients with unexplained recurrent spontaneous abortion (URSA).DesignProspective clinical study.SettingUniversity hospital.Patient(s)125 URSA patients, 35 normal early pregnant women, and 28 normal nonpregnant women.Intervention(s)Measurements of CD4+CD25high T cells and FOXP3 expression in peripheral blood and decidua.Main Outcome Measure(s)The proportions of CD4+CD25high T cells and FOXP3 expression.Result(s)In peripheral blood, statistically significantly higher proportions of CD4+CD25high T cells and FOXP3 expression were observed in normal early pregnant women compared with normal nonpregnant women and URSA patients; a statistically significantly lower proportion of CD4+CD25high T cells was observed in nonpregnant URSA patients compared with URSA patients who had early miscarriages and normal nonpregnant women. In the decidua, statistically significantly lower proportions of CD4+CD25high T cells and FOXP3 expression were found in URSA patients with early miscarriages compared with normal early pregnant women.Conclusion(s)The CD4+CD25high T cells may play an important role in maintaining a normal pregnancy. The reduction in CD4+CD25high T cells may involve in the pathogenesis of URSA, and is correlated with lower FOXP3 expression.