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 (FE NO ) 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 FEV 1 , > or =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 FEV 1 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 microM and 334.6 microM vs 798.4 microM; P < .01 and P < .05, respectively). No difference in EBC leukotriene B 4 levels was found among the 3 groups. Both asthmatic groups had higher FE NO levels than control subjects ( P < .001). EBC Cys-LT ( P < .01; r = 0.7) and FE NO ( P < .05; r = 0.5) values both correlated significantly with the postexercise FEV 1 decrease.

CONCLUSION

this study shows that EBC Cys-LT values are higher in asthmatic children with EIB and correlate with the decrease in FEV 1 after exercise. These findings suggest that the pathways of both Cys-LT and nitric oxide are involved in the pathogenesis of EIB.