An Increase of Treg Cells in the Peripheral Blood is Associated with a Better In Vitro Fertilization Treatment Outcome

Abstract

The objective of this study was to determine whether there was any association between the peripheral blood CD4(+) CD25(+) Foxp3(+) regulatory T cells (Treg cells) and implantation success in patients undergoing in vitro fertilization (IVF) treatment. Prospective observational study of 101 randomly selected women who underwent IVF treatment for tubal factor from May 2011 to June 2011. The percentage of peripheral blood Treg cells and the expression levels of Foxp3 and CTLA4 mRNA in peripheral blood mononuclear cells (PBMCs) were recorded and their relations to IVF treatment outcomes were analyzed. Treg cells were significantly elevated in the pregnant group ( P = 0.03). The expression level of Foxp3 mRNA in PBMCs from pregnant group also significantly increased ( P = 0.02). A receiver operating characteristic analysis (area under curve = 0.631) found that those women with Treg cells >0.6%, the pregnancy rate and live birth rate were much higher as compared to women with Treg cells below this level ( P < 0.05). An increase of Treg cells in the peripheral blood was associated with a better IVF treatment outcome (OR 4.3, 95% CI = 1.76-10.48), with a sensitivity of 64%, specificity of 71%. An elevated level of circulating Treg cells was associated with increased rates of pregnancy and live birth in IVF treatment.