<b>Background:</b> The pathogenetic mechanims of neutrophilic asthma are not well understood now. Whether T helper (Th)17-mediated immunity contributes to the pathogenesis of neutrophilic asthma in human is still under investigation. The aim of this study was to explore the relationship between Th17-mediated immunity and airway inflammation in childhood neutrophilic asthma. <b>Methods:</b> Twenty-eight children with exacerbated asthma and without using any glucocorticoids were divided into three groups: eosinophilic asthma (EA, n  =  12) group, neutrophilic asthma (NA, n  =  10) group and paucigranulocytic asthma (PGA, n  =  6) group according to the induced sputum cytology. Ten healthy children were recruited as healthy control (HC, n  =  10) group. Peripheral Th17 and Th2 cells, and the expression of Ki-67 in peripheral Th17 cells were detected by flow cytometry. The mRNA expression of retinoic acid-related orphan receptor γt (RORγt) in peripheral blood mononuclear cells (PBMCs) was detected by qRT-PCR. The concentrations of IL-17, IL-8 and IL-5 in sputum, as well as IL-17 in plasma and culture supernatant of activated PBMCs were measured by ELISA. <b>Results:</b> The percentage of Th17 cells in peripheral Th cells, and the concentrations of IL-17, IL-8 in sputum, as well as IL-17 in culture supernatant of activated PBMCs were all increased in NA group, and positively correlated with neutrophil level in sputum and with each other. Also, the mRNA expression of RORγt in PBMCs and Ki-67 positivity in peripheral Th17 cells were both increased in NA group. The percentage of Th2 cells in peripheral Th cells, and the concentration of IL-5 in sputum were both increased in EA group, and positively correlated with eosinophil level in sputum and with each other. <b>Conclusions:</b> Both Th17- and Th2-mediated immunity are involved in the pathogenesis of childhood asthma. There is predominance of Th17-mediated immunity and Th17 cells proliferation in childhood neutrophilic asthma.

中文翻译：

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儿童中性粒细胞哮喘：Th17 淋巴细胞的影响

<b>背景：</b> 中性粒细胞性哮喘的发病机制目前还不是很清楚。T辅助（Th）17介导的免疫是否有助于人类中性粒细胞哮喘的发病机制仍在研究中。本研究的目的是探讨 Th17 介导的免疫与儿童中性粒细胞哮喘气道炎症之间的关系。<b>方法：</b> 28 例未使用任何糖皮质激素的哮喘加重患儿分为三组：嗜酸性哮喘（EA，n = 12）组、中性粒细胞哮喘（NA，n = 10）组和少粒细胞哮喘组。哮喘（PGA，n=6）组按诱导痰细胞学检查。招募十名健康儿童作为健康对照组（HC，n = 10）。外周 Th17 和 Th2 细胞，流式细胞仪检测外周Th17细胞中Ki-67的表达。qRT-PCR检测外周血单个核细胞（PBMCs）中视黄酸相关孤儿受体γt（RORγt）的mRNA表达。ELISA法测定痰液中IL-17、IL-8和IL-5的浓度，以及血浆和活化PBMCs培养上清液中的IL-17浓度。<b>结果：</b> NA增加外周Th细胞中Th17细胞的百分比，痰液中IL-17、IL-8和活化PBMCs培养上清液中IL-17的浓度均升高。组，与痰中性粒细胞水平呈正相关，相互之间呈正相关。此外，NA组PBMC中RORγt的mRNA表达和外周Th17细胞中Ki-67阳性均增加。外周Th细胞中Th2细胞的百分比，电针组痰液中IL-5浓度均升高，且与痰液中嗜酸性粒细胞水平呈正相关，相互之间呈正相关。<b>结论：</b> Th17和Th2介导的免疫均参与了儿童哮喘的发病机制。在儿童中性粒细胞哮喘中，Th17 介导的免疫和 Th17 细胞增殖占优势。