Once-daily theophylline reduces serum eosinophil cationic protein and eosinophil levels in induced sputum of asthmatics

Background: Because eosinophilic airway inflammation is a characteristic fe ature of bronchial asthma, the treatment of airway inflammation is importan t in the management of asthma. Theophylline has been reported to reduce air way inflammation, in addition to its well-known bronchodilating effect. Obj ective: In order to evaluate the effects of theophylline on airway inflamma tion, we investigated 48 subjects with mild and moderate asthma. Methods: T he patients were randomly divided into two groups, with or without theophyl line treatment (control n = 24; theophylline, n = 24). We examined the leve l of serum eosinophil cationic protein (ECP), induced sputum samples, and p eak expiratory flow (PEF) and obtained spirograms before and after 4 weeks of treatment with once-daily theophylline (200-600 mg/day) of subjects with mild or moderate asthma. Results: Theophylline significantly increased mor ning and evening PEF and significantly decreased the diurnal variation of P EF. After treatment with theophylline, both serum ECP and the percentage of eosinophils in induced sputum were significantly decreased. In contrast, p eripheral blood eosinophil count was unchanged after treatment with theophy lline. Conclusions: These findings suggest that theophylline reduces airway inflammation and the severity of asthma, presumably via suppression of bot h eosinophil activity and subsequent eosinophil infiltration of the airways . Copyright (C) 2000 S. Karger AG, Basel.