Airway effects of local challenge with hypertonic saline in exercise-induced asthma.

Hypertonicity of airway lining fluid has been suggested as the stimulus for bronchoconstriction in exercise-induced asthma. We explored the airway effects of delivering a direct hypertonic stimulus to asthmatic airways via a fiberoptic bronchoscope, comparing hypertonic saline challenge by direct instillation with local aerosol delivery. A group of 18 asthmatic subjects responsive to inhaled hypertonic saline with a history of EIA were studied; the first 9 subjects received local challenge with hypertonic saline by direct instillation, and the next 9 subjects were challenged by local aerosol delivery. A control challenge with isotonic saline by either instillation or aerosol was performed at a same bronchoscopy. Local challenge with hypertonic saline by aerosol delivery was found to be more effective in inducing local bronchoconstriction (8 of 9 subjects) than instillation (2 of 6 subjects). Paired BAL fluid samples and bronchial biopsies were obtained in total of 11 and 9 subjects, respectively. Local ch...