Diagnostic value of a pattern of exhaled breath condensate biomarkers in asthmatic children

Background: Diagnosing asthma in children is a challenge and using a single biomarker from exhaled breath condensate (EBC) showed the lack of improvement in it. Objective: The aim of this study was to assess the diagnostic potential of a pattern of simple chemical biomarkers from EBC in diagnosing asthma in children in a real-life setting, its association with lung function and gastroesophageal reflux disease (GERD). Methods: In 75 consecutive children aged 5-7 years with asthma-like symptoms the following tests were performed: skin prick tests, spirometry, impulse oscillometry (I0S), exhaled NO (FENO), 24-hour oesophageal pH monitoring and EBC collection with subsequent analysis of pH, carbon dioxide tension, oxygen tension, and concentrations of magnesium, calcium, iron and urates. Results: No significant differences were found for individual EBC biomarkers between asthmatics and non-asthmatics (p > 0.05 for all). A pattern of six EBC biomarkers showed a statistically significant (p = 0.046) predictive model for asthma (AUC = 0.698, PPV = 84.2%, NPV = 38.9%). None to moderate association (R-2 up to 0.43) between EBC biomarkers and lung function measures and FENO was found, with IOS parameters showing the best association with EBC biomarkers. A significantly higher EBC Fe was found in children with asthma and GERD compared to asthmatics without GERD (p = 0.049). Conclusions: An approach that involves a pattern of EBC biomarkers had a better diagnostic accuracy for asthma in children in real-life settings compared to a single one. Poor to moderate association of EBC biomarkers with lung function suggests a complementary value of EBC analysis for asthma diagnosis in children. (C) 2016 SEICAP. Published by Elsevier Espana, S.L.U. All rights reserved.