Chu H W, Halliday J L, Martin R J, Leung D Y, Szefler S J, Wenzel S E
Department of Medicine, National Jewish Medical and Research Center and the University of Colorado Health Sciences Center, Denver, Colorado, USA.
Am J Respir Crit Care Med. 1998 Dec;158(6):1936-44. doi: 10.1164/ajrccm.158.6.9712073.
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.
慢性气道炎症和重塑，包括纤维化，被认为是哮喘病理生理学的重要促成因素。先前关于气道纤维化的研究主要在轻度和中度哮喘患者的上皮下“基底膜”（SBM）水平进行。本研究旨在通过三种不同的胶原染色方法，评估17例重度、9例中度和7例轻度哮喘患者以及8例正常对照受试者的支气管活检中大气道SBM厚度和黏膜下胶原沉积情况。还检测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受试者在SBM厚度、黏膜下胶原沉积、嗜酸性粒细胞数量或TGF-β阳性细胞方面均无统计学显著差异。仅当将所有哮喘患者（n = 33）一起检查时，与正常对照受试者相比，通过III型胶原免疫染色评估发现SBM有适度增厚（p = 0.04）。尽管存在这种差异，但在比较所有哮喘患者和正常对照受试者时，黏膜下胶原沉积量、嗜酸性粒细胞数量或表达TGF-β的细胞数量均未发现显著差异。此外，在胶原沉积与嗜酸性粒细胞计数、TGF-β表达水平、第一秒用力呼气容积（FEV1）或哮喘病程之间未发现显著相关性。这些结果表明，尽管大气道水平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。
