ABSTRACT
Objective To investigate Treg and Th17 cell numbers in the peripheral blood of patients with unexplained recurrent spontaneous abortion (URSA),with an aim to elevate their potential for predicting pregnancy outcomes.Methods Peripheral blood was collected from 60 URSA pregnant women and 56 healthy pregnant women during their first trimester in the Department of Reproductive Endocrinology of the Second Affiliated Hospital of Soochow University from January 2014 to June 2015.The counts of regulatory T cell (Treg),T helper cell 17 (Th17),CD4 positive T cell (CD4+ T cell) and total lymphocytes in the peripheral blood were determined by flow cytometry.Calculated the ratios of Treg/CD4+ T cells,Treg/total lymphocytes,Th17/CD4+ T cells,Th17/total lymphocytes and Treg/Th17,then the pregnancy outcomes were followed up.According to the different pregnancy outcomes,the patients were divided into three groups: URSA successful delivery group (23 cases),URSA re-miscarriage group (37 cases) and normal successful delivery group (44 cases).Non-parametric test were used to compare the differences between groups.Results There were no difference between the URSA re-miscarriage group and URSA successful delivery group in the CD4+ T cell counts[(1 570.16±519.56) vs (1 571.83±450.37),t=0.01,P=0.99]and total lymphocytes[(4 497.11±975.48) vs (4 558.52±1 032.54),t=0.23,P=0.82].However,the ratios of Treg/CD4+ T cells[(1.09±0.62) vs (3.32±2.30),t=4.55,P=0.000 1],Treg/total lymphocytes[(0.42±0.24) vs (1.31±1.14),t=3.67,P=0.001 3]and Treg/Th17[(0.56±0.41) vs (2.51±2.38),t=3.89,P=0.000 8]in the URSA miscarriage again group were significantly lower whereas the ratios of Th17/CD4+ T cells[(1.85±0.92) vs (0.93±0.36),t=5.40,P<0.001]and Th17/total lymphocytes[(0.64±0.31) vs (0.31±0.14),t=5.52,P<0.001]were significantly higher.Similarly,There were no difference between the URSA re-miscarriage group and normal successful delivery group in the CD4+ T cell counts[(1 570.16±519.56) vs (1 566.86±651.36),t=0.03,P=0.98]and total lymphocytes[(4 497.11±975.48) vs (4 720.91±1 572.92),t=0.78,P=0.44].However,the ratios of Treg/CD4+ T cells[(1.09±0.62) vs (3.17±1.81),t=7.16,P<0.001],Treg/total lymphocytes[(0.42±0.24) vs (1.03±0.51),t=7.08,P<0.001]and Treg/Th17[(0.56±0.41) vs (1.87±1.68),t=4.98,P<0.001]in the URSA re-miscarriage group were significantly lower whereas the ratios of Th17/CD4+ T cells[(1.85±0.92) vs (1.12±0.50),t=4.29,P<0.001]and Th17/total lymphocytes[(0.64±0.31) vs (0.36±0.15),t=5.01,P<0.001]were significantly higher.Conclusions Treg and Th17 cell counts in the peripheral blood of patients with URSA might be useful in predicting their pregnancy outcomes.The decrease of Treg cell counts and the increase of Th17 cell counts might imply another abortion.