探讨重症肺炎患儿外周血辅助性T细胞(Th)17、调节性T细胞(Treg)及其细胞因子的表达水平及临床意义。

选取2013年1月至2015年6月，于湖北医药学院附属人民医院确诊为重症肺炎的52例患儿，纳入研究组。选择同期于本院进行健康体检的30例健康儿童，纳入对照组。采用流式细胞术检测2组受试者外周血中，Th17及Treg于CD₄⁺ T细胞所占比例，以及Th17与Treg比值(Th17/Treg)。采用酶联免疫吸附测定(ELISA)法检测2组受试者外周血的血清白细胞介素(IL)-17、-6、-10和转化生长因子(TGF)-β水平。统计学比较2组受试者外周血中，Th17及Treg于CD₄⁺ T细胞所占比例，Th17/Treg，以及血清IL-17、-6、-10与TGF-β水平。本研究遵循的程序符合湖北医药学院附属人民医院人体试验委员会制定的伦理学标准，得到该委员会批准，并与所有受试者监护人均签署了临床研究知情同意书。

①研究组受试者外周血中，Th17于CD₄⁺ T细胞所占比例为12.1%±3.0%，显著高于对照组的8.5%±1.5%，二者比较，差异有统计学意义(t＝5.982，P<0.001)。②研究组受试者外周血中，Treg于CD₄⁺ T细胞所占比例为3.4%±0.1%，显著低于对照组的8.7%±1.2%，二者比较，差异有统计学意义(t＝33.134，P<0.001)。③研究组受试者外周血中，Th17/Treg为0.49±0.17，显著高于对照组的0.23±0.08，二者比较，差异有统计学意义(t＝14.971，P<0.001)。④与对照组受试者相比较，研究组受试者外周血的血清IL-10和TGF-β水平显著下降，IL-17、-6水平显著升高，并且差异均有统计学意义(t＝36.758、26.746、34.312、42.145，P<0.001)。

重症肺炎患儿外周血中Th17及其相关细胞因子表达水平显著升高，Treg及相关细胞因子表达水平下降，Th17/Treg显著升高，这提示Th17/Treg失衡在重症肺炎的发生及发展机制中发挥重要作用。Th17/Treg检测对于重症肺炎的临床治疗，具有一定指导意义。

To study expression levels of T helper cell (Th) 17 and regulatory T cell (Treg) and their cytokines in peripheral blood of children with severe pneumonia, and their clinical significances.

From January 2013 to June 2015, a total of 52 children who were diagnosed as severe pneumonia in People′s Hospital Affiliated to Hubei University of Medicine were included in study group. A total of 30 healthy children who received health examination in the same hospital during the same period were included in control group. The ratios of Th17 and Treg in CD₄⁺ T, and Treg/Th17 in peripheral blood were measured by flow cytometry. The levels of serum interleukin (IL)-17, -6, -10 and transforming growth factor (TGF)-β in peripheral blood were measured by enzyme-linked immunosorbent assay (ELISA) of two groups. The ratios of Th17 and Treg in CD₄⁺ T, and Treg/Th17, and the levels of serum IL-17, -6, -10 and transforming growth factor (TGF)-β in peripheral blood between two groups were compared by statistical methods. This study was in line with the ethics standards promulgated by the Human Subjects Committee of People′s Hospital Affiliated to Hubei University of Medicine and approved by the committee, and obtained the informed consents from all the chlidren′s guardians.

①The ratio of Th17 in CD₄⁺ T in peripheral blood of children with severe pneumonia in study group was 12.1%±3.0%, which was significantly higher than that of control group 8.5%±1.5%, and the difference was statistically significant (t=5.982, P<0.001). ②The ratio of Treg in CD₄⁺ T in peripheral blood of children with severe pneumonia in study group was 3.4%±0.1%, which was significantly lower than that of control group 8.7%±1.2%, and the difference was statistically significant (t=33.134, P<0.001). ③The Th17/Treg in peripheral blood in study group was 0.49±0.17, which was significantly lower than that in control group 0.23±0.08, and the difference was statistically significant (t=18.620, P<0.001). ④Compared with control group, the levels of serum IL-10 and TGF-β in peripheral blood of study group were significantly decreased, the levels of serum IL-17 and IL-6 were significantly increased, and all the differences were statistically significant (t= 36.758, 26.746, 34.312, 42.145; P<0.001).

The expression levels of Th17 and its related cytokines in peripheral blood of children with severe pneumonia are significantly increased, while the expression levels of Treg and its related cytokines are decreased, and the Th17/Treg is increased significantly, suggesting that Th17/Treg imbalance occurs in the pathogenesis and development of severe pneumonia and plays an important role. Th17/Treg balance test has a certain guiding significance for the clinical treatment of severe pneumonia.