Effects of a leukotriene receptor antagonist on exhaled leukotriene E4 and prostanoids in children with asthma

BackgroundLeukotriene (LT) E4 and 8-isoprostane concentrations are elevated in exhaled breath condensate in children with asthma. The effects of leukotriene receptor antagonists (LTRAs) on exhaled leukotriene and prostanoids in children with asthma are unknown.Objective(1) To study the effect of montelukast, a LTRA, on exhaled LTE4, 8-isoprostane, and prostaglandin E2 in children with asthma and atopic children; (2) to measure exhaled nitric oxide.MethodsAn open-label study with oral montelukast (5 mg once daily for 4 weeks) was undertaken in 17 atopic children with asthma and 16 atopic children without asthma.ResultsPretreatment exhaled LTE4 (P < .0001) and 8-isoprostane (P < .0001) values were higher in atopic children with asthma than in atopic children without asthma. In atopic children with asthma, montelukast reduced exhaled LTE4 by 33% (P < .001), and this reduction was correlated with pretreatment LTE4 values (r = −0.90; P = .0001). Posttreatment exhaled LTE4 levels in children with asthma were higher than pretreatment LTE4 values in atopic children without asthma (P < .004). Montelukast had no effect on exhaled LTE4 in atopic children without asthma (P = .74), or on exhaled 8-isoprostane (atopic children with asthma, P = .94; atopic children without asthma, P = .55) and PGE2 (atopic children with asthma, P = .56; atopic children without asthma, P = .93) in both groups. In atopic children with asthma, exhaled nitric oxide concentrations were reduced by 27% (P < .05) after montelukast.ConclusionLeukotriene receptor antagonists decrease exhaled LTE4 in atopic children with asthma. This reduction is dependent on baseline exhaled LTE4 values.Clinical implicationsMeasurement of exhaled LTE4 might help identify children with asthma most likely to benefit from LTRAs.