Evidence of airway inflammation and remodeling in ski athletes with and without bronchial hyperresponsiveness to methacholine

Asthma-like symptoms, methacholine hyperresponsiveness, and use of asthma m edication are prevalent in elite cross-country skiers. We quantitated mucos al inflammatory cell infiltration and tenascin expression in the subepithel ial basement membrane in endobronchial biopsy specimens of the proximal air ways from 40 elite, competitive skiers (mean: 17.5; range: 16 to 20 yr) wit hout a diagnosis of asthma, in 12 subjects with mild asthma, and in 12 heal thy controls, through immunohistochemistry and indirect immunofluorescence, respectively. All of the subjects were nonsmokers. T-lymphocyte, macrophag e, and eosinophil counts were, respectively, greater by 43-fold (p < 0.001) , 26-fold (p < 0.001), and twofold (p < 0.001) in skiers, and by 70-fold (p < 0.001), 63-fold (p < 0.001), and eightfold (p < 0.001) in asthmatic subj ects than in controls. In skiers, neutrophil counts were more than twofold greater than in asthmatic subjects, and mast cell counts were not significa ntly different than in controls. Tenascin expression (as measured through t he thickness of the tenascin-specific immunoreactivity band in the basement membrane) was increased in skiers (median: 6.7 mu m; interquartile range [ IQR]: 5.3 to 8.5 mu m, p < 0.001) and asthmatic subjects (mean: 8.8 mu m; I QR: 7.2 to 10.8 mu m, p < 0.001) compared with controls (mean: 0.8 mu m; IQ R: 0 to 3.1 mu m) and did not correlate with inflammatory cell counts. Infl ammatory changes were present irrespective of asthmalike symptoms, hyperres ponsiveness, or atopy. Prolonged repeated exposure of the airways to inadeq uately conditioned air may induce inflammation and remodeling in competitiv e skiers.