Imbalance of Th17/Treg in the pathogenesis of bronchiolitis

ObjectiveTo investigatethe the levels of helper T lymphocyte 17(Th17)/regulatory T lymphocyte(Treg) and related cytokines in children with bronchiolitis, and its correlation with the progress of disease.

MethodsEighty-three children with bronchiolitis were divided into the light disease group(42 cases), medium disease group(21 cases) and severe disease group(20 cases), and 30 healthy physical examination children at the same time were set as the control group.The ratio of Th17 and Treg to CD4⁺T cells were detected using flow cytometry.The serum concentrations of interleukin(IL)-6, IL-10, IL-17 and IL-35 were detected using ELISA, and the differences of above indicators were analyzed among four groups.

ResultsThe ratio of Th17 cells and levels of pro-inflammatory factors of IL-17 and IL-6 in case group were significantly higher than those in control group(P<0.05), while the ratio of Treg cells and production of anti-inflammatory factors of IL-10 and IL-35 in case group were significantly lower than those in control group(P<0.05), especially in the severe group.The results of Pearson correlation analysis showed that the level of Th17 was positively correlated with levels of Th17/Treg, IL-17 and IL-6, and the level of Treg was positively correlated with levels of IL-10 and IL-35, and negatively correlated with Th17/Treg.The levels of Th17/Treg, Th17 and IL-17 were negatively correlated with IL-35(P<0.05 to P<0.01).The results of logistic regression analysis showed that the odds ratio of severe bronchiolitis to Th17/Treg, IL-17 and IL-6 were statistically significant(P<0.05 to P<0.01).

ConclusionsThe imbalance of Th17/Treg plays an important role in the pathogenesis of bronchiolitis.Th17/Treg, IL-7 and IL-6 are the risk factors of severe bronchiolitis.