气道上皮IL-25促进哮喘气道重塑

IL-25 derived from epithelial cells has the potential to promote airway remodeling in asthma

目的:通过检测白细胞介素-25(IL-25)在嗜酸细胞性哮喘(EA)及非嗜酸细胞性哮喘(NEA)患者的血清、诱导痰及气道上皮中的表达,探讨其在支气管哮喘气道重塑中的作用。方法:选取初诊的哮喘患者55例,健康对照组27例,所有受试者均进行肺通气功能检查,然后采集空腹静脉血及诱导痰。据诱导痰中嗜酸性粒细胞(EOS)的比例将哮喘患者分为EA组和NEA组。采用ELISA检测血清及诱导痰中IL-25的水平,同时对其中的10例EA组患者、10例NEA组患者及10例健康对照者行电子支气管镜气道黏膜活检,免疫组织化学技术分析IL-25在气道上皮的表达,HE染色测量气道重塑的重要指标-基底膜厚度,并行血清及诱导痰中IL-25的水平与基底膜平均厚度的相关性分析。结果:与正常对照组相比,EA和NEA组哮喘患者的肺功能轻度受损。ELISA结果显示哮喘患者血清及诱导痰中IL-25的水平明显高于对照组(P<0.05),而EA和NEA组哮喘患者间差异无统计学意义(P>0.05)。免疫组织化学结果显示哮喘患者气道上皮IL-25的表达明显高于对照组,HE染色显示气道黏膜下的基底膜厚度明显增加(P<0.05)。相关性分析显示哮喘患者血清及诱导痰中IL-25水平与气道黏膜下基底膜平均厚度成正相关。结论:IL-25可能有促进哮喘气道重塑的作用,嗜酸性粒细胞与基底膜厚度无明显相关性,其在哮喘气道重塑中的作用可能是有限的。

AIM： To explore the role of interleukin-25 （IL-25） in the pathogenesis of eosinophilic asthma （EA） and non-eosinophilic asthma （NEA） through detecting its expression in serum, induced sputum and bronchial epithelial mucosa of asthmatic patients. METHODS： Serum and induced sputum were collected from 55 untreated asthmatic patients and 27 healthy control subjects. The asthmatic patients were divided into EA and NEA groups according to sputum eosinophils（EOS） percentage （3% as a dividing point）. The level of IL-25 in serum and induced spntum was determined by ELISA; the expression of IL-25 in bronchial epithelium was quantified by immunohistochem- istry in biopsied specimens from 10 cases of EA, 10 NEA and l0 controls. Basement membrane thickness as an important index of airway remodeling was detected by HE staining. RESULTS： Compared with healthy control sub- jects, the lung function was impaired in patients with EA and NEA. ELISA results showed that the levels of IL-25 in the serum and induced sputum of asthmatic patients were signif- icantly higher than those in healthy subjects （ P 〈 0.05）. But there were no statistic differences between EA and NEA pa- tients （P〉0.05）. The immunohistochemical results indica- ted that the expression of IL-25 was higher in asthmatic bronchial epithelium than in control ones. HE staining showed that the basement membrane thickness increased in EA and NEA patients （ P 〈 0. 05 ）. Correlation analysis showed that the levels of IL-25 in serum and induced sputum were positively correlated with the average thickness of basement membrane in asthmatic patients. CONCLUSION. IL-25 secreted from epithelial cells has the potential to promote airway remodeling in asthma. EOS has nothing to do with the thickness of basement membrane, and it may not be necessary for airway remodeling in asthma.