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 (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.


CONCLUSIONS
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.
Carraro
Silvia
S
Department of Pediatrics, University of Padua, Via Giustiniani 3, 35128 Padua, Italy.
Corradi
Massimo
M
Zanconato
Stefania
S
Alinovi
Rossella
R
Pasquale
Maria Francesca
MF
Zacchello
Franco
F
Baraldi
Eugenio
E
D000085:Acetates / Q000627:therapeutic use; D000293:Adolescent; D000641:Ammonia / Q000032:analysis / Q000378:metabolism; D001250:Asthma, Exercise-Induced / Q000188:drug therapy / Q000503:physiopathology*; D015415:Biomarkers / Q000032:analysis*; D001944:Breath Tests; D016084:Bronchoconstriction / Q000187:drug effects; D002648:Child; D003521:Cyclopropanes; D003545:Cysteine / Q000032:analysis* / Q000187:drug effects / Q000378:metabolism; D045853:Exhalation; D005541:Forced Expiratory Volume; D006801:Humans; D020024:Leukotriene Antagonists / Q000627:therapeutic use; D007975:Leukotriene B4 / Q000032:analysis / Q000378:metabolism; D015289:Leukotrienes / Q000032:analysis* / Q000378:metabolism; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism; D011804:Quinolines / Q000627:therapeutic use; D012129:Respiratory Function Tests; D013440:Sulfides
D000085:Acetates; D015415:Biomarkers; D003521:Cyclopropanes; D020024:Leukotriene Antagonists; D015289:Leukotrienes; D011804:Quinolines; D013440:Sulfides; C112381:cysteinyl-leukotriene; D007975:Leukotriene B4; D009569:Nitric Oxide; D000641:Ammonia; D003545:Cysteine; C093875:montelukast