Asthmatic patients were studied by bronchoalveolar lavage (BAL) and bronchial biopsy (BB), either unchallenged or after an allergen bronchial challenge. In the unchallenged group, a higher airway responsiveness (AR) was observed in those patients known to have a late-phase asthmatic response (LAR), and this was associated with an increased ratio of degranulating to total mast cells in BB. In challenged patients, AR was increased before the development of LAR, and correlated with the number of eosinophils in BAL. Lung mechanics studies showed that the increase of AR before LAR was not associated with a decrease of the bronchodilator effect of deep inhalation, which was found only during LAR. Altogether these results suggest that: 1) the increased baseline AR in patients with LAR is sustained by ongoing mast cell degranulation; 2) the increase in AR that precedes LAR reflects an increased sensitivity of airway smooth muscle, probably due to eosinophil- derived products; and 3) the increase in AR following LAR may be in part due to abnormalities in airway and lung mechanics.
|Number of pages||3|
|Journal||European Respiratory Review|
|Publication status||Published - 1993|
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine