Immune Imbalance Of Th17/Treg Cells And The Relationship Among IL-17,IL-35 And Infectious Preterm Birth

Objective:To investigate the relationship between Th17/Treg cell immune imbalance,related cytokines（IL-17,IL-35）and infectious preterm birth（IPB）for providing new experimental indicators for clinical prediction of IPB.Methods:Forty pregnant women(28³6⁺⁶ weeks)who were delivered from December2017 to November 2018 in the Affiliated Hospital of Zunyi Medical University were selected as experimental groups.According to the results of fetal membrane pathology,they were divided into premature infection group（IPB,24 cases）and premature non-infection group（nIPB,16 cases）.Another 20 full-term pregnant women(FTP,37⁴1⁺⁶weeks)who gave birth at the same time were selected as the control group.Firstly,The positive expression rates of Th17 cells and Treg cells in peripheral blood CD4+T cells were detected by flow cytometry;Secondly,the expression of IL-17 and IL-35 in the serum of three groups was detected by enzyme-linked immunosorbent assay.Results:（1）Compared with the preterm non-infected group and the full-term pregnancy group,the positive rate of Th17 cells（0.64±0.063%）in premature infection group increased（0.64±0.063%）,the positive rate of Treg cells（0.048±0.014%）decreased,and the ratio of Th17/Treg cells（13.61±3.05）raised,which the difference was statistically significant（P<0.05）.The above three indicators were not significantly different between the other two groups（P>0.05）.（2）The expression of IL-17 in the premature infection group was higher than that of the preterm non-infected group and the full-term pregnancy group（20.41±5.25pg/ml）,the difference was statistically significant（P<0.01）,but there was no significant difference between the other two groups（P>0.05）;There was no significant difference in the expression level of IL-35 between the three groups（P>0.05）,but the premature infection group showed a downward trend compared with the others.（3）The positive expression rates of Th17 cells and the expression of IL-17 in the premature infection group were positively correlated with common infection detection indicators（such as C-reactive protein,procalcitonin,IL-6,leukocytes and neutrophils）;The positive expression rates of Treg cells and IL-35 expression were negatively correlated with the above commonly used infection detection indicators.Conclusion:Th17/Treg cell immune imbalance is closely related to infectious preterm labor.Dynamic monitoring of changes in the positive rate of Th17 cells,Treg cells and changes in IL-17 expression levels,can be used as a new indicator for predicting IPB.