Effects of different anti-asthmatic agents on induced sputum and eosinophil cationic protein in mild asthmatics

Inhaled corticosteroids, leukotriene receptor antagonists, and theophylline are recommended for the treatment of mild persistent asthma. The aim of this study was to compare the changes in sputum total cell and eosinophil counts, and eosinophil cationic protein (ECP) levels in serum and sputum following treatment with leukotriene receptor antagonists, inhaled corticosteroids, and theophylline in patients with mild persistent asthma.

Total cell counts, eosinophil percentage, and ECP levels in induced sputum and serum were determined both before and after treatment. Prior to sputum induction, FEV1 and PEF values and symptom scores were recorded at baseline and after 8 weeks of treatment. After baseline measurements, the asthmatic patients (n = 30) were randomized into three groups. A total of 10 patients were treated with zafirlukast, 20 mg bd, 10 with budesonide inhaler 200 microg bd, and 10 with theophylline 200 mg bd.

There were significant decreases in sputum total cell counts and eosinophil percentage in all treatment groups. However, the decrease in sputum eosinophil counts was more significant in the corticosteroid-treated group. Although sputum ECP levels decreased significantly in the groups treated with zafirlukast and budesonide (zafirlukast group, 580-135 microg/L, P < 0.01; budesonide group, 683-268 microg/L, P < 0.01), the decrease was not statistically significant in the theophylline-treated group (498-361 microg/L, P > 0.05). In contrast, there were no significant changes in serum ECP levels in any of the treatment groups.

All three treatments resulted in significant decreases in sputum total cell counts and eosinophil percentage, but the decrease in sputum ECP level was only seen in the groups treated with budesonide and zafirlukast. These results suggest that although all three treatments are considered as first-line treatments in most consensuses, theophylline seems to have less of an inhibitory effect on eosinophil activation.