Mast cells in bronchoalveolar lumen of patients with bronchial asthma.

Bronchoalveolar lavage was performed on patients with stable bronchial asthma to elucidate the existence and significance of mast cells in human bronchoalveolar lumen. The percentage of total mast cell population, in which 2 different types of mast cells could be identified morphologically in lavage fluids, was 0.25 +/- 0.19% (mean +/- SD) in asthmatic patients and 0.08 +/- 0.02% in control subjects. The number of mast cells in asthmatic patients was greater than in control subjects (p less than 0.05). The histamine content per mast cell in bronchoalveolar lumen was calculated to be 8.2 +/- 6.0 pg/cell in asthmatic patients and 15.3 +/- 10.8 pg/cell in control subjects, which suggests that the " releasability " of histamine is greater in asthmatic patients during asymptomatic periods than it is in control subjects, although the differences were not statistically significant. Our results suggest that an increase in the mast cell population of bronchoalveolar lumen is significant in the pathogenesis of bronchial asthma.