Inhibition of eosinophil activation in bronchoalveolar lavage fluid from atopic asthmatics by Y-24180, an antagonist to platelet-activating factor

Abstract We examined the effects of Y-24180, a potent and long-acting antagonist to platelet-activating factor (PAF) receptor, on the expression of adhesion molecules in peripheral blood and bronchoalveolar lavage fluid (BALF) eosinophils from atopic asthmatics. Y-24180 (20 mg/day) was administered to 4 atopic asthmatics for 8 weeks. The number of eosinophils, the level of eosinophil cationic protein (ECP), the bindings of soluble intercellular adhesion molecule-1 (sICAM-1) and fibronectin (FN), and the expressions of CD11b (alpha chain of Mac-1) and CD49d (alpha chain of VLA-4) on eosinophils were evaluated in peripheral blood (n = 4) and BALF (n = 3) before and after the administration of Y-24180. The infiltration of eosinophils into the bronchial wall was also examined by taking biopsies. Eosinophil count, sICAM-1 and FN binding to eosinophils in BALF significantly decreased after the administration of Y-24180 (p