Enhanced prostaglandin E-2 secretion in sputum from asthmatic patients after zafirlukast therapy

Background and Purpose: Leukotrienes are important inflammatory mediators o f bronchial asthma that cause bronchoconstriction, mucous secretion, and in creased vascular permeability. Current guidelines recommend anti-leukotrien e agents as alternative treatments for asthma; however, data on their anti- inflammatory effect is lacking. Methods: The purpose of this study was to determine the anti-inflammatory e ffect of zafirlukast, a leukotriene antagonist, in patients with bronchial asthma. A total of 30 adult patients with mild persistent asthma received 6 weeks of zafirlukast treatment. Peak expiratory flow rate (PEFR) was deter mined before and after therapy to assess clinical efficacy. Both serum and sputum samples were collected before and after therapy and concentrations o f eosinophil cationic protein (ECP), prostaglandin E-2 (PGE(2)), and leukot riene E-4 (LTE4) were measured. Results: A significant improvement in PEFR was found after zafirlukast ther apy (p = 0.017). There was also a significant reduction in serum ECP concen tration (13.6 +/- 2.4 mug/L vs 10.3 +/- 2.1 mug/L, p < 0.025) and a signifi cant increase in sputum PGE(2) concentration (112.7 +/- 14.0 pg/mL vs 176.8 +/- 32.1 pg/mL, P < 0.01). The percentage eosinophil count and the concent rations of ECP and LTE4 in the sputum were not significantly different afte r therapy. Conclusion: This study found a significant reduction in serum ECP and a sig nificant increase in sputum PGE(2) concentrations in asthmatic patients aft er zafirlukast treatment, both of which were significantly associated with improvement in PEFR. The modulation of PGE(2) and ECP production might occu r through the antiinflammatory effect of zafirlukast.