Background: Cysteinyl leukotrienes are important mediators of airway inflammation, whereas 8-isoprostane is a biomarker of oxidative stress. This study evaluated the distributions of cysteinyl leukotriene and 8-isoprostane concentrations in exhaled breath condensates (EBCs) of children. The relationship between cysteinyl leukotriene and 8-isoprostane concentrations in the EBCs was also evaluated.
Methods: The EBCs were collected from 34 children with allergic respiratory diseases and 24 healthy children. All recruited children underwent pulmonary function testing every season. The severity of allergic respiratory diseases and medication status were assessed every month in children with allergic respiratory diseases.
Results: The EBC cysteinyl leukotriene and 8-isoprostane levels were higher in children with asthma and allergic rhinitis than in those with asthma only and healthy children. In asthmatic children, cysteinyl leukotriene and 8-isoprostane levels peaked in the summer. All children showed a clear association between EBC cysteinyl leukotriene and EBC 8-isoprostane levels.
Conclusion: The cysteinyl leukotriene and 8-isoprostane concentrations in the EBCs of children significantly varied by season. Oxidative stress correlated with airway inflammation in children.