哮喘患儿外周血调节性T细胞和 Th1/Th2 的变化及其与哮喘病情的关系

Changes of regulatory T cells and T helper cells in peripheral blood and their roles in the severity evaluation in children with asthma

摘要:

目的：通过测定哮喘患儿外周血 CD4+CD25+Foxp3+ 调节性T细胞（Treg）以及 Th1/Th2 比值变化，探讨其与哮喘病情的关系。方法：150 例哮喘患儿按临床表现分为急性期组 (94 例) 和缓解期组 (56 例), 其中急性期组按病情再分为轻度组 (54 例) 和重度组 (40 例)。应用流式细胞仪检测各组外周血 CD4+CD25+Foxp3+ Treg、CD4+IFN-γ+ Th1 和 CD4+IL-4+ Th2 水平，并与正常儿童（对照组，n=50）进行比较。结果：哮喘组 Treg 水平明显低于对照组 (P<0.01)：其中急性期组 Treg 水平明显低于缓解期组和对照组(P<0.01)，重度组 Treg 水平则明显低于轻度组(P<0.01)。哮喘组 Th1/Th2 比值显著低于对照组 (P<0.01)。哮喘急性期组 Th1/Th2 比值显著低于缓解期组和对照组 (P<0.01)。哮喘患儿外周血 Treg 水平与哮喘的病情严重程度呈负相关 (r=-0.737, P<0.01)，Th1/ Th2 比值与哮喘病情严重程度亦呈负相关 (r=-0.615, P<0.01)，且Treg 的水平与 Th1/ Th2 比值呈正相关(r=0.856, P<0.01)。结论：哮喘患儿外周血Treg 水平明显降低，Th 亚群失衡，提示 Treg 和 Th 免疫在哮喘发病中具有重要作用。外周血Treg 水平与 Th1/Th2 比值可用来评估哮喘病情。

Abstract:

OBJECTIVE: To investigate the changes of CD4+CD25+Foxp3+ regulatory T cells (Treg) and T helper cells (Th1/Th2) in peripheral blood and their roles in the severity evaluation in children with asthma. METHODS: One hundred and fifty children with asthma were classified into acute attack (94 cases) and remission (56 cases) groups according to their clinical features, and the acute attack children were subdivided into mild asthma (54 cases) and severe asthma (40 cases) groups. Fifty healthy children were enrolled as a control group. The levels of CD4+CD25+Foxp3+ Treg, CD4+IFN-γ+ Th1 and CD4+IL-4+ Th2 in peripheral blood were measured by flow cytometer. RESULTS: The mean levels of CD4+CD25+Foxp3+ Treg and the ratio of Th1/Th2 in asthmatic children were lower than those in the control group (P<0.01). The Treg levels and the ratio of Th1/Th2 in the acute attack group were lower than those in the remission group and in the control group (P<0.01). The Treg levels in the severe asthma group were lower than those in the mild asthma group (P<0.01). There was a remarkably negative correlation between Treg levels and the asthma severity (r=-0.737, P<0.01), and the Th1/Th2 ratio was also negatively correlated with the asthma severity (r=-0.615, P<0.01). The Treg levels were positively correlated with the Th1/Th2 ratio (r=0.856, P<0.01). CONCLUSIONS: The Treg levels decrease remarkably and Th subsets imbalance occurs in children with asthma. This suggests that Treg and Th immunity play important roles in the pathogenesis of asthma. The Treg levels and the ratio of Th1/Th2 in peripheral blood may be useful in the evaluation of severity in children with asthma.