Role Of Th22 Cells,Th17 Cells And Treg Cells In The Pathogenesis Of Severe Preeclampsia

Preeclampsia(PE)is a common pregnancy specific disease,that affects 3～5% of all pregnancies.It is characterized by new-onset hypertension with systolic blood pressure ≥140mm Hg or diastolic blood pressure ≥90mm Hg,measure on two occasions at least four hours apart,and proteinuria of ≥0.3g per 24 hours or ≥1+ proteinuria after 20 weeks of pregnancy.It is one of the main causes of maternal and perinatal morbidity and mortality globally.Although the etiology and pathogenesis of PE has not been fully elucidated,PE has come to understood as a complex disorder involving several factors including genetic,failure of the cytotrophoblast cells penetrate into the myometrial segment of the spiral arteries,poor angiogenesis,insulin resistance and immune maladaptation).Among them,the role of the immune system in the etiology of preeclampsia is of great importance.T helper cells,also known as CD4+T cells,are an important part of the immune system.This includes Th1,Th2,Th17,Th22,Th9,and Treg cells which are characterized by specific cytokine profiles.Recently,it was demonstrated that Th cells,such as Th1 and Th2 cells,participated in the pathogenesis and progression of PE,with a predominance of the production of Th1 cytokines.Therefore,in this study,we focus on the role of Th22 cells,Th17 cells and Treg cells in the pathogenesis of severe preeclampsia.ObjectiveThe current study aimed to determine the the frequencies of Th17,Th22 and Treg cells in the peripheral blood along with the plasma concentrations of IL-17 A,IL-22 and IL-10 in sPE patients and healthy pregnant women,in order to evaluate the role of Th22 cells,Th17 cells and Treg cells in the pathogenesis of sPE.Materials and Methods1 Materials Thirty sPE patients from the third affiliated hospital of Zhengzhou University between October 2014 and February 2016 were enrolled in this study as the sPE group.An additional 30 healthy pregnant women during the same period were recruited in this study as a control group.The two groups of pregnant women were Chinese Han people.All pregnant participants with multifetal gestation,diabetes mellitus,autoimmune disease,chronic hypertension,renal disorders,or angiopathy in the course of pregnancy were excluded,and none of the study or control subjects had active labor at the time of enrollment and blood sampling.The diagnostic criteria of sPE refered to the eighth edition of “obstetrics and gynecology ” published by the People’s Medical Publishing House.The study has been reviewed and approved by Zhengzhou University Clinical Trial Ethics Committees.Informed consent was obtained from all participants entering this study.2 Methods Blood samples from the sPE group and the control group were obtained by venipuncture using sterile,heparin-treated tubes.Flow cytometry was used to detect the percentages of Th17,Th22 and Treg cells in the peripheral blood of sPE patients and healthy pregnant women.ELISA was used to measure the plasma concentrations of IL-22,IL-17 A and IL-10.3 Statistics analysis Statistical analysis was performed using SPSS 22.0.The test for normality was performed according to Kolmogorov-Smirnov.The measurement data of normal distribution were presented as the means ± standard deviation.The measurement data of non-normal distribution were presented as median(P25~P75).An Independent student’s t-test and Mann-Whitney U-test were applied to determine the significant differences between 2 groups depending on the data distribution.Spearman’s correlation test was used for correlation analysis.A p value less than 0.05 was considered statistically significant.Results1 Clinical characteristics of sPE patients and healthy pregnant womenThe average maternal age of the sPE group and the control group were respectively(30.8±5.4)years and(29.5±3.7)years,the weeks of blood collection were respectively(32.8±3.2)weeks and(32.2±3.7)weeks,According to statistic analysis,no statistically significant differences were found in the maternal age or weeks of blood collection between the sPE group and the control group(P>0.05).The systolic blood pressure were respectively(165.3±14.8)mm Hg and(115.0±8.2)mm Hg,the diastolic blood pressure were respectively(108.5±9.6)mm Hg and(72.9±6.3)mm Hg,the plasma concentration of uric acid were respectively(407.5±87.3)mmol/L and(244.5±62.3)mmol/L,the neonatal birth weight were respectively(2 012.5±770.8)g and(3 330.0±459.2)g.In addition,the sPE group was detected in the emergence of urinary protein,while the control group was not.According to statistic analysis,the systolic pressure,diastolic pressure,proteinuria and plasma concentra-tion of uric acid in the sPE group were significantly higher than those in the control group(P<0.05).In contrast,the neonatal birth weight in the sPE group was signify-cantly lower than that in the control group(P<0.05).2 The percentages of Th22 cells,Th17 cells and CD4+ IL-17+ IL-22+ cells in the sPE group and the control groupThe percentage of Th22 cells in the sPE group was 0.59%(0.39~1.13)%,and the percentage of Th22 cells in the control group was 0.40%(0.23~0.57)%.The percentage of Th22 cells in the peripheral blood of the sPE group was significantly higher than those in the control group(P<0.05).The percentage of Th17 cells in the sPE group was 3.24%(3.02~3.97)%,and the percentage of Th17 cells in the control group was 1.87%(1.53~2.64)%.The percentage of Th17 cells was markedly increased with sPE compared to that in the control group,with statistically significant difference(P<0.05).The percentage of IL-17A/IL-22 double positive T cells was increased in the sPE group[0.32%(0.13~0.59)% ]than that in the control group[0.15%(0.08~0.26)%],with statistically significant difference(P<0.05).3 The percentages of Treg cells in the sPE group and the control groupThe percentages of Treg cells in the sPE group and the control group were respectively(3.92±1.02)% and(6.24±1.85)%.According to the statistic analysis,significantly decreased frequencies of Treg cells were found in the sPE group compared with the control group(P<0.05).4 The plasma concentrations of IL-17 A,IL-22 and IL-10 in the sPE group and the control groupThe concentration of plasma IL-22 in the sPE group was significantly higher than that in the control group,the concentrations were 285.72 pg/m L(247.63～306.69)and 233.85 pg/m L(184.92～258.38)pg/m L respectively,with statistically difference(P<0.05).And the concentrations of plasma IL-17 A were 27.53 pg/m L(23.84～32.78)and 17.36 pg/m L(15.58～19.13)pg/m L in the sPE group and the control group respectively,and the difference between the two groups was significant(P<0.05).In contrast,the concentration of plasma IL-10 was obviously lower in the sPE group than that in the control group(P<0.05),the concentrations were(26.83±4.87)pg/m L and(33.59±5.26)pg/m L respectively.5 Comparisons of the Th17/Treg and Th22/Treg ratios in the sPE group and the control groupThe ratio of Th17 cells to Treg cells in the peripheral blood of the sPE group was 0.88(0.74~1.20),and the ratio of Th17 cells to Treg cells in the contol group was 0.30(0.26~0.45).The ratio of Th17 cells to Treg cells in the peripheral blood of the sPE group was significantly higher than that in the control group(P<0.05).Similarly,the ratio of Th22 cells to Treg cells[0.19(0.12~0.32)]in the peripheral blood of the sPE group was obviously higher than that in the control group[0.09(0.05~0.12)](P<0.05).6 Correlation analysis on the percentages of Th17 and Th22 cells in the sPE group and the control groupA positive correlation was found between the levels of Th22 and Th17 cells in the sPE group(r=0.534,P=0.015).However,no correlation was found between the levels of Th22 and Th17 cells in the control group(r=0.345,P=0.136).7 correction analysis between plasma IL-22 concentration and the percentage of Th22 cells and Th17 cells in the sPE groupA positive correlation was observed between the plasma IL-22 concentration and circulating Th22 frequency in the sPE group(r=0.600,P=0.005).However,no correlation was found between the plasma IL-22 concentration and circulating Th17 frequency in the sPE group(r=0.398,P=0.082).ConclusionThe immune imbalance between Th17 and Treg cells,Th22 and Treg cells may be closely related to development of sPE.