Hydrogen Peroxide in Exhaled Breath Condensate in Asthmatic Children during Acute Exacerbation and after Treatment

Background: In asthmatics, the concentration of hydrogen peroxide (H2O2) in exhaled breath condensate (EBC) has been found to be increased and to be related to airway inflammation. Objective: The aim of this study was to determine whether in children with acute exacerbation, exhaled H2O2 levels could be influenced by treatment and linked to airway obstruction. Methods: Twenty-two asthmatic children (mean age 9.4 years, range 6-14) with asthma exacerbation and 12 healthy children (mean age 11.7 years, range 7-15) were enrolled. Concentrations of exhaled H2O2 before and after standard treatment for asthma attack were compared with those of controls and with clinical observation. Asthmatic children and controls underwent spirometry and skin prick tests to common aeroallergens. Results: Exhaled H2O2 concentrations were significantly higher in children with asthma both before (median 0.273 mu M; p < 0.001) and after pharmacologic treatment (median 0.303 mu M; p = 0.001) compared to control values (median 0.045 mu M). After treatment, exhaled H2O2 concentrations remained significantly higher in children with and without auscultatory wheezing than in controls (p = 0.034 and p < 0.001, respectively). EBC H2O2 levels in asthmatics before treatment did not differ from those after treatment. No correlation was found between H2O2 and forced expiratory volume in 1 s values. All asthmatics but one were atopics. Conclusions: In children with acute asthma exacerbation, exhaled H2O2 concentrations in EBC are significantly elevated. In the short-term follow-up, H2O2 levels remain at high levels and are not correlated with lung function or improvement in symptoms. Copyright (C) 2012 S. Karger AG, Basel