The Journal of clinical investigation
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Randomized Controlled Trial Clinical Trial
Perception of bronchial obstruction in asthmatic patients. Relationship with bronchial eosinophilic inflammation and epithelial damage and effect of corticosteroid treatment.
We studied the perception of bronchoconstriction in asthmatic subjects who were randomly treated with inhaled beta 2 agonist given either alone (n = 9) or associated with inhaled corticosteroids (n = 9). Methacholine and bradykinin challenges, bronchoalveolar lavage, and bronchial biopsies were performed in all subjects. After each dose of agonist, breathlessness was assessed using a visual analog scale (VAS) and the forced expiratory volume in 1 s (FEV1) was measured. ⋯ VAS/FEV1 slopes for bradykinin but not for methacholine correlated negatively with the magnitude of eosinophilic inflammation in airway mucosa. VAS/FEV1 slopes for each agonist correlated positively with the percentage of basement membrane covered by airway epithelium. We conclude that in asthmatic patients perception of bronchoconstriction is related to eosinophilic inflammation and to epithelial damage in airways and that corticosteroid treatment is associated with improved perception of bronchoconstriction induced by bradykinin, a mediator endogenously produced in asthma.