Exhaled breath condensate cysteinyl leukotrienes are increased in children with exercise-induced bronchoconstriction

Background: It is recognized that airway inflammation has a central role in the pathogenesis of asthma, but how it relates to exercise-induced bronchoconstriction (EIB) is not completely understood. Objective: The aim of our study was to investigate the relationship between EIB and baseline concentrations of cysteinyl leukotrienes (Cys-LTs) and other inflammatory markers in exhaled breath condensate (EBC). Methods: EBC was collected, and the fraction of exhaled nitric oxide (FENO) was measured in a group of 19 asthmatic children, after which they performed a treadmill exercise test. Fourteen healthy children were enrolled as control subjects. Results: The asthmatic children were divided into the EIB group (decrease in FEV1, >= 12%) and the non-EIB group. The EBC was analyzed for the presence of Cys-LTs, leukotriene B-4, and ammonia. Asthmatic patients with EIB (mean FEV1 decrease, 23% +/- 3%) had higher Cys-LT concentrations than either asthmatic patients without EIB or control subjects (42.2 pg/mL [median] vs 11.7 pg/mL and 5.8 pg/mL; P <.05 and P <.001, respectively). Ammonia concentrations were lower in both the EIB and non-EIB groups than in control subjects (253.2 mu M and 334.6 mu M vs 798.4 mu M; P <.01 and P <.05, respectively). No difference in EBC leukotriene B4 levels was found among the 3 groups. Both asthmatic groups had higher FENO levels than control subjects (P <.001). EBC Cys-LT (P <.01; r = 0.7) and FENO (P <.05; r = 0.5) values both correlated significantly with the postexercise FEV1 decrease. Conclusion: this study shows that EBC Cys-LT values are higher in asthmatic children with EIB and correlate with the decrease in FEV1 after exercise. These findings suggest that the pathways of both Cys-LT and nitric oxide are involved in the pathogenesis of EIB.