Effect of montelukast on basophil releasability in patients with asthma

Background: The anti-inflammatory effect of montelukast, a leukotriene receptor antagonist, in patients with bronchial asthma is not entirely clear. Basophils can release a variety of mediators, including histamine and leukotriens, which most likely play an active role in the late allergic response. Objectives: To study the effect of montelukast (10 mg/day) on histamine and cysteinyl leukotriene release from basophils taken from 12 mild atopic asthmatic patients who took the drug for 4 weeks. Methods: Basophils were withdrawn at baseline, and after 48 hours, I week, and 4 weeks of therapy. Histamine was measured by a radioenzymatic method and leukotrienes by immunologic assay. Histamine and cysLT release was measured spontaneously and following stimulation with interleukin-3 and anti-immunoglobulin E. Spirometry and symptom score were measured before and during treatment. Results: During the treatment with montelukast there were no significant changes in spontaneous, IL-3 and anti-IgE-induced histamine release. cysLT release decreased significantly only after 4 weeks of treatment (from 2899 +/- 550 pg/ml at baseline to 2225 +/- 430 pg/ml at 4 weeks, P= 0.02). Conclusions: Montelukast does not seem to affect the release of histamine from basophils but mildly inhibits the cysLT release seen after 4 weeks of treatment.