Airway Basophil and Mast Cell Density in Patients with Bronchial Asthma: Relationship to Bronchial Hyperresponsiveness

Abstract

We investigated the role of basophils and mast cells in the pathogenesis of bronchial asthma. Eight asthmatics (6 atopic, 2 nonatopic) and 6 control subjects were enrolled in this study. Bronchial responsiveness to acetylcholine (PC₂₀ACh) was measured in asthmatics, and endobronchial biopsy from right upper lobe bronchus was performed on the same day. Basophils and mast cells in the airways were identified by immunohistochemistry using a monoclonal antibody against tryptase and anti-IgE. The number of basophils of asthmatics was 52.2 ± 12.5/mm². In contrast, no basophils were found in the airways of control subjects. There was a significant increase of number of mast cells in the asthma group compared to the control group (168.6 ± 32.6 vs. 22.3 ±6.1, p < 0.01). There was an inverse correlation between airway basophil and mast cell numbers and PC₂₀AGh (r = -0.82, r = 0.72, p < 0.05). These findings suggest a possible role for basophils and mast cells in the pathophysiology of asthma.