Effect of montelukast on polymorphonuclear leukocyte functions in asthmatic patients U ¨ mran Soyog ˘ul Gu ¨rer a , Suna Bu ¨yu ¨ko ¨ztu ¨rk b ,S ßu ¨kru ¨ Palandu ¨z c , Burc ßak Gu ¨rbu ¨z a , Adile C ßevikbas ß a, * a Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Marmara, Tıbbiye Caddesi No: 49 Haydarpas ßa, Istanbul 81010, Turkey b Department of Allergy, Faculty of Medicine, I ˙ stanbul University, Istanbul, Turkey c Department of Internal Medicine, Division of Medical Genetics, Faculty of Medicine, I ˙ stanbul University, Istanbul, Turkey Received 19 November 2002; received in revised form 9 January 2003; accepted 24 January 2003 Abstract Leukotriene receptor antagonists are being used widely in the treatment of bronchial asthma. They have been shown to possess anti-inflammatory properties, but there is no sufficient data about their effects on polymorphonuclear leukocyte functions. The aim of this study was to investigate the effects of montelukast, a specific cysteinyl leukotriene-1 receptor antagonist, on human polymorphonuclear leukocyte (PMN) functions (phagocytic and intracellular killing activity) in asthmatic patients. Fifteen mild to moderate asthmatic patients were included in the study. They were treated with montelukast (10 mg/day per os) in addition to their previous medications for 2 weeks. Whole blood samples of patients were taken before and after this treatment period. Phagocytic activities and intracellular killing activities of polymorphonuclear leukocytes isolated from whole blood samples were tested by using appropriate technics. Phagocytic and intracellular killing activities of PMNs were significantly increased ( p < 0.001, p < 0.05) by montelukast compared to those before treatment. These results show that montelukast has an enhancing effect on PMN functions in asthmatic patients. D 2003 Elsevier B.V. All rights reserved. Keywords: Montelukast; Polymorphonuclear leukocytes; Asthma; Allergic inflammation 1. Introduction Leukotrienes are potent chemical mediators in allergic inflammation [1,2]. Leukotriene receptor antagonists are a new class of oral asthma drugs that target and block the action of these mediators [3–7]. Anti-inflammatory effects of these drugs on the air- way of asthmatic patients have been demonstrated by many studies [8–11]. Their clinical benefits include improved symptoms, reduced rescue bronchodilator requirements and reduced inhaled steroid require- ments [2]. They are also being suggested for allergic rhinitis recently [12]. However, there is not much 1567-5769/03/$ - see front matter D 2003 Elsevier B.V. All rights reserved. doi:10.1016/S1567-5769(03)00043-2 * Corresponding author. Tel.: +90-216-414-2962/102; fax: +90- 216-345-2952. E-mail address: umran.gurer@veezy.com (A. C ßevikbas ß). www.elsevier.com/locate/intimp International Immunopharmacology 3 (2003) 1257 – 1260