Effect of inhaled corticosteroid treatment on exhaled breath condensate leukotriene E4 in children with mild asthma

Chronic airway inflammation in children with asthma might be present even in the absence of pathological lung function tests and is known to increase the risk of permanent pulmonary damage. Thus, we aimed at investigating to what extent inflammatory markers such as leukotrienes (LTs) in exhaled breath condensate (EBC) or fractional exhaled nitric oxide (FENO) reflect therapeutic effects in these patients. Fifty steroid-naivc patients (aged 8.8 +/- 2.7 years) were included in the study. EBC was collected before and 6 months after therapy with inhaled corticosteroids. LTs were determined by using commercially available ELISA. In addition, FENO was measured by means of a chemiluminescence analyzer. Conventional lung function testing was performed revealing vital capacity, forced expiratory volume, maximum expiratory flow, and specific resistance. In EBC, LTE4, but not LTB4 levels significantly decreased after steroid therapy from 45.3 +/- 36.0 pg/mL to 17.2 +/- 11.4 pg/mL (p < 0.0001) concomitant with a slight, but significant improvement of lung function parameters. Mean FENO also indicated therapeutic success; however, in 20 of 50 patients, exhaled NO concentrations were higher after therapy. These findings suggest that LTE4 in breath condensate may be helpful in latent inflammatory activity in the bronchial mucosa in children with asthma.