Stimulation of alveolar macrophages in asthmatic patients after local provocation test.

Dermatophagoîdes pteronyssinus allergen was instilled into the alveolar space of 7 allergic asthmatic patients during bronchoalveolar lavage. beta-glucuronidase concentration in the bronchoalveolar fluid from the challenged lung became significantly higher than that in the opposite control lung (3.90 +/- 1.88 nmol/h versus 0.86 +/- 0.55). The intracellular level of beta-glucuronidase in the alveolar macrophages in the challenged lung was 40.3% lower than that in the control lung. In 3 controls intracellular concentrations of beta-glucuronidase were similar before and after allergenic challenge and no enzyme activity could be detected in bronchoalveolar lavage fluid. These results suggest that alveolar instillation of an allergen in asthmatic patients rapidly stimulates alveolar macrophages, which may be involved in immediate hypersensitivity reactions in asthma.