Airway inflammation and basement membrane tenascin in newly diagnosed atopic and nonatopic asthma

Abstract

Previous studies have shown both similar and distinct inflammatory changes in atopic and nonatopic asthma. This study was set to investigate the bronchial inflammatory cell infiltrate and subepithelial basement membrane (BM) tenascin deposition in subjects with newly diagnosed asthma and bronchial hyperresponsiveness (BHR). Seventy-nine asthmatic subjects (age 18-60 years) were recruited and 58 were atopic according to skin prick testing. The patients recorded asthma symptoms and peak flow measurements for 14 days. Lung function and BHR were measured by spirometry and histamine challenge. Serum eosinophil cationic protein (ECP) and blood eosinophils were assessed. Fiberoptic bronchoscopy was performed to obtain bronchial biopsies. Serum ECP was higher in the atopic group but eosinophil counts did not differ. There were no differences in inflammatory cells studied (activated eosinophils, T-lymphocytes, mast cells or macrophages) between nonatopic and atopic subjects. BM tenascin layer was significantly thicker in atopic compared with nonatopic subjects (7.6 vs 6.3 microm, P = 0.007). The thickness of tenascin correlated with eosinophil, T-lymphocyte, and macrophage counts, as well as with IL-4-positive cell counts and the correlation was seen only in atopic asthmatics. These findings suggest that inflammatory cells may have a regulatory role in tenascin expression in atopic asthma.

Airway remodeling and inflammation in competitive swimmers training in indoor chlorinated swimming pools

“…[21][22][23] In atopic controls, Djukanovic et al showed that these changes are similar in nature but less marked compared with those in atopic asthmatic subjects. 23 In elite winter athletes, increases in airways' tenascin thickness or inflammatory cell counts were observed, independently of atopy, having significant airway remodeling and inflammation compared with controls.…”

Airway Remodeling in Asthma and its Influence on Clinical Pathophysiology

“…Thickening of epithelial basement membrane has been observed as a characteristic remodeling for asthma for a long time but was also found in early asthma (Karjalainen et al 2000(Karjalainen et al , 2003. Thickening of basement membrane observed with microscopy correspond to the deposition of extracellular matrix (ECM) at subepithelial space observed by electron microscopy, and it is called subepithelial fibrosis (Roche et al 1989;Jeffery et al 1992).…”

Epithelial Tenascin Predicts Obliterative Airway Disease

“…15 Patients with asthma exhibit tenascin expression near the epithelial cells. 16 Tenascin expression has also been detected in benign and malignant lung tumors, but the intensity of staining seems to be especially strong in the stroma of squamous cell carcinomas. 14,17 In usual interstitial pneumonia, tenascin is expressed in early fibrotic lesions.…”