HIGH-AFFINITY IGE RECEPTOR (FC-EPSILON-RI)-BEARING CELLS IN BRONCHIALBIOPSIES FROM ATOPIC AND NONATOPIC ASTHMA

Asthma is characterized by bronchial mucosal inflammation. Although al lergen-induced activation of cells binding allergen-specific immunoglo bulin E (IgE) through high-affinity receptors (Fc epsilon RI) is belie ved to play some role in asthma, inappropriate synthesis of total or a llergen-specific IgE cannot be demonstrated in some (''intrinsic'') pa tients despite the fact that the nature of the bronchial inflammation is similar to that in atopic (''extrinsic'') asthmatics. We have studi ed the numbers and phenotype of Fc epsilon RI-bearing cells in bronchi al biopsies from 12 atopic and 10 nonatopic asthmatic patients and com pared our findings with 10 atopic and 12 nonatopic control subjects us ing single and double immunohistochemistry. Significantly increased nu mbers of Fc epsilon RI-bearing cells were identified in bronchial biop sies from atopic and nonatopic asthmatics and atopic control subjects when compared with normal controls (p = 0.001, 0.006, and 0.0006, resp ectively). In asthmatics and atopics the majority of Fc epsilon RI-bea ring cells were identified as mast cells and macrophages; a much small er percentage were eosinophils. We conclude that elevated numbers of h igh-affinity IgE receptor-bearing cells are a feature of bronchial bio psies of asthmatic subjects, irrespective of their atopic status.