The effect of theophylline on blood and sputum eosinophils and ECP in patients with bronchial asthma

It was recently reported that theophylline has an anti-inflammatory and bronchodilating effect on bronchial asthma. Accordingly, to examine the anti-inflammatory effect of theophylline on asthma, especially its effect on eosinophil activation, a sustained-release theophylline preparation (Theolong) was administered (daily dose: 400 mg) to 18 patients with mild to moderate bronchial asthma. This was done in order to study the preparation's effects on lung function, blood and sputum eosinophils and ECP four weeks pre- and post-administration. Lung function was determined by spirometry and sputum by induced sputum. Blood and sputum ECP levels were determined using an ECP RIA kit. In lung function, there were no differences in vital capacity (VC) or in forced expiratory volume 1 s (FEV 1.0) pre- and post-administration. There were also no differences in the number of blood and sputum eosinophils, but serum and sputum ECP levels decreased. Theophylline is thus expected to exert an inhibitory effect on eosinophil activation and it is suggested as an effective therapeutic drug for bronchial asthma.