Collagen deposition in large airways may not differentiate severe asthma from milder forms of the disease
Collagen deposition in large airways may not differentiate severe asthma from milder forms of the disease
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DOI：
10.1164/ajrccm.158.6.9712073
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发表时间：
1998-12-01
影响因子：
24.7
通讯作者：
Wenzel, SE
中科院分区：
文献类型：
--
作者：
Chu, HW;Halliday, JL;Wenzel, SE
慢性气道炎症和重塑，包括纤维化，已被认为是哮喘病理生理学的重要贡献者。以前的研究主要是在轻度和中度哮喘患者的上皮下“基底膜”（SBM）水平上进行的。本研究旨在评估17例重度、9例中度和7例轻度哮喘患者以及8例正常对照组支气管内活检标本中大气道SBM厚度和粘膜下胶原沉积，采用三种不同的胶原染色方法进行测量。还检查了组织嗜酸性粒细胞和转化生长因子-β（TGF-β）免疫反应性。三组哮喘患者与正常对照组之间的SBM厚度、粘膜下胶原沉积、嗜酸性粒细胞数量或TGF-β阳性细胞均无统计学差异。只有当检查所有的哮喘患者（n = 33），适度增厚的SBM（p = 0.04），通过III型胶原免疫染色评价，观察到与正常对照组相比。尽管存在这种差异，但当比较总哮喘患者和正常对照受试者时，在粘膜下胶原沉积量和嗜酸性粒细胞或TGF-β表达细胞的数量方面没有发现显著差异。此外，胶原沉积与嗜酸性粒细胞计数、TGF-β表达水平、FEV 1或哮喘持续时间之间没有显著相关性。这些结果表明，虽然在大气道水平的SBM中胶原沉积增加是哮喘的一个特征，但它可能无法解释哮喘严重程度的差异。
Chronic airway inflammation and remodeling, including fibrosis, have been proposed as important contributors to asthma pathophysiology. Previous studies of airway fibrosis have been performed mainly in mild and moderate asthmatics at the subepithelial "basement membrane" (SBM) level. The current study was designed to evaluate the large airway SBM thickness and submucosal collagen deposition, as measured by three different collagen staining methods, in endobronchial biopsies from 17 severe, nine moderate, and seven mild asthmatics, as well as eight normal control subjects. Tissue eosinophils and transforming growth factor-beta (TGF-beta) immunoreactivity were also examined. There were no statistically significant differences in the SBM thickness, submucosal collagen deposition, eosinophil numbers, or TGF-beta positive cells among the three groups of asthmatics and the normal control subjects. It was only when examining all asthmatics (n = 33) together, that a modestly thickened SBM (p = 0.04), as evaluated by collagen type III immunostaining, was observed as compared with normal control subjects. Despite this difference, no significant differences were found in the amount of submucosal collagen deposition and the number of eosinophils or TGF-beta expressing cells when comparing total asthmatics and normal control subjects. Additionally, no significant correlations were found between collagen deposition and eosinophil count, TGF-beta expression level, FEV1, or duration of asthma. These results suggest that although increased collagen deposition in the SBM at the large airway level is a characteristic of asthma, it may not explain the differences in severity of asthma.