Oxidative stress and airway inflammation after allergen challenge evaluated by exhaled breath condensate analysis

Summary Background Allergen exposure may increase airway oxidative stress, which causes lipid membrane peroxidation and an increased formation of 8‐isoprostane. Objective The aim of the study was to investigate oxidative stress induced by allergen challenge in mild asthmatics, by measuring 8‐isoprostane in exhaled breath condensate (EBC), and to examine their relationship with mediators derived from arachidonic acid. Methods 8‐isoprostane, cysteinyl leukotrienes (cys‐LTs) and prostaglandin E2 (PGE2) concentrations in EBC were measured at baseline and after allergen challenge in 12 patients with mild allergic asthma sensitized to cat allergen. Results At 24 h after allergen challenge, compared with baseline values, EBC 8‐isoprostane increased [48.64 pg/mL (44.14–53.61) vs. 21.56 pg/mL (19.92, 23.35), P