Abstract:

Abstract：Objective　Explore the role of Th cell and related cytokines in immune pathogenesis of children with asthma. Methods　Twenty children with asthma and 20 age-matched healthy children were studied. Flow cytometric analysis was used to detect the percentage of Th1，Th2，Th17 and CD4+CD25+ regulatory T （Treg） cells. The induced sputum from those children was collected to count and classify inflammatory cells. Realtime PCR was used to analyze the expression of T-bet，IFN-γ，GATA3，IL-4，Foxp3，TGF-β，RORrt，IL-17A，IL-8 and TNF-α mRNA in peripheral blood mononucear cell and induced sputum. Results　（1）The percentages of Th1 and Treg cell in children with asthma were significantly lower than those in healthy controls（P < 0.05），and there was no significant difference in the percentages of Th2 and Th17 cell between asthma patients and controls （P > 0.05）； （2） Expression levels of the T-bet，Foxp3，IFN-γ，TGF-β in the children during acute phase of asthma were significanttly lower than those in healthy control subjects（P < 0.05）， but the expression levels of the GATA3，RORγt，IL-4 and IL-17A were of no difference between the two groups； （3）The number of neutrophils and eosonophils in induced sputum significantly， increased in the children with acute phase asthma（P < 0.05）；（4） Expression levels of GATA3，IL-4，IL-5，RORγt，IL-17A，IL-8 and TNF-α in indued sputum were significanttly increased in asthmatic children （P < 0.05），but there were no difference about the expression levels of T-bet，IFN-γ，Foxp3 and TGF-β between the two groups. Conclusion　Increase of Th2 and Th17 transcription factors and cytokines in airway of children with asthma might play an impaortant role in airway inflammation.

Key words: asthma, induced sputum, Th cell, immune imbalances

摘要：

探讨支气管哮喘患儿诱导痰中辅助性T细胞（Th）亚群及相关细胞因子的变化及意义。方法　观察2009年9月至2010年1月深圳儿童医院收集的20例哮喘患儿及20例同年龄对照组儿童，采用流式细胞术检测哮喘患儿外周血Th1、Th2、Th17、CD4+CD25+调节性T细胞（Treg）数量；同时收集哮喘患儿和对照组儿童的诱导痰，进行炎性细胞计数与分类，荧光定量聚合酶链反应（Real Time PCR）测定外周血单个核细胞及诱导痰T-bet、IFN-γ、GATA3、IL-4、Foxp3、TGF-β、RORrt、IL-17A、IL-8、TNF-α等mRNA表达水平。结果　（1）急性期哮喘患儿外周血Th1、Treg细胞比例降低（P < 0.05）、Th2细胞、Th17细胞比例与正常对照组差异无统计学意义（P > 0.05）。（2）急性发作期哮喘患儿外周血单个核细胞T-bet、Foxp3、IFN-γ、TGF-β表达降低（P < 0.05），GATA3、RORγt、IL-4、IL-17A 与正常对照组差异无统计学意义（P > 0.05）。（3）急性发作期哮喘患儿诱导痰中性粒细胞、嗜酸性粒细胞数量增加（P < 0.05）。（4）急性发作期哮喘患儿诱导痰中RORγt、IL-17A、GATA3、IL-4、IL-5、IL-8、TNF-α表达增高（P < 0.05），T-bet、IFN-γ、Foxp3、TGF-β表达与正常对照组差异无统计学意义（P > 0.05）。结论　哮喘患儿诱导痰Th2与Th17转录因子和细胞因子增多，可能是导致儿童哮喘气道炎症反应的重要原因。

关键词: 哮喘, 诱导痰, Th细胞, 免疫失衡