[Allergic inflammation in the development of nonspecific bronchial hyperresponsiveness in asthma].

Bronchial hyperresponsiveness, an exaggerated bronchoconstrictor response to a variety of nonspecific stimuli, is regarded as one of the most important feature in bronchial asthma. It can be demonstrated by bronchial provocation tests with pharmacological or physical stimuli. The measured level of responsiveness to these agents is considered to reflect the lability of the airways and the severity of the disease. Acute exposure to allergen causes an increase of airway responsiveness. The significant correlation between the allergen-induced increase in hyperresponsiveness and the severity of the late asthmatic reaction suggests the same underlying mechanisms that include an influx of inflammatory cells in the airways occurring during late phase of response to allergens. Marked inflammation with infiltration of eosinophils and disruption of airway epithelium has been also described on autopsies of patients who died of acute asthma but also on bronchial biopsies of subjects with mild asthma. Development and persistence of increased nonspecific bronchial responsiveness are possibly associated with these inflammatory changes.