@article {SchleichOA1466, author = {Florence Schleich and Kirill Bessonov and Jan Dallinga and Virginie Paulus and Monique Henket and Agnes Boots and Agnieszka Smolinska and Emiel Wouters and Frederik-J. Van Schooten and Renaud Louis}, title = {Do volatile organic compounds (VOCs) discriminate between eosinophilic and neutrophilic asthma phenotype?}, volume = {46}, number = {suppl 59}, elocation-id = {OA1466}, year = {2015}, doi = {10.1183/13993003.congress-2015.OA1466}, publisher = {European Respiratory Society}, abstract = {Oxidative stress generates volatile organic compounds (VOCs). Induced sputum is currently the best available noninvasive assessment of bronchial inflammation in asthma. We currently lack of markers for airway neutrophilia. The purpose of the study was to examine whether specific VOCs are associated with eosinophilic and neutrophilic inflammation.Methods: This prospective study recruited 276 asthmatics from the asthma clinic of CHU Liege between 2010 and 2014. Patient underwent VOCs measurement by GCMS analysis, FENO, spirometry with bronchodilation, sputum induction, blood sample and validated asthma control and quality of life questionnaires. One week later, methacholine challenge was performed. We used conditional inference forests to rank features based on the ability of components to predict phenotypes.The chemical nature of the compounds was found in NIST Library.Results: 3328 VOCs were detected in the exhaled air from eosinophilic (eos>=3\%, n=122), neutrophilic (neutro>=76\%, n=50) and paucigranulocytic (n=90) asthmatics. We filtered out components that were detected in \<30 samples. When comparing VOCs from paucigranuloctytic to eosinophilic asthma, 3 components (P337, P903, P923) were good discriminators. We found that P2622 and P2853 were VOCs able to distinguish between neutrophilic and paucigranulocytic while peak 253 and 1913 were best for eosinophilic versus neutrophilic discrimination. The chemical nature of these compounds cannot be unveiled as a patent has been submitted.Our study is the first attempt to characterize VOCs according to sputum inflammatory phenotypes in a large asthmatic population and shows that VOCs may be a valuable method to phenotype asthmatics.}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/46/suppl_59/OA1466}, eprint = {https://erj.ersjournals.com/content}, journal = {European Respiratory Journal} }