RT Journal Article SR Electronic T1 Exhaled volatile organic compounds and lung microbiome in COPD: a pilot randomised controlled trial JF ERJ Open Research JO erjor FD European Respiratory Society SP 00253-2021 DO 10.1183/23120541.00253-2021 VO 7 IS 4 A1 Mohan, Divya A1 Keir, Holly R. A1 Richardson, Hollian A1 Mayhew, David A1 Boyer, Joseph A1 van der Schee, Marc P. A1 Allsworth, Max D. A1 Miller, Bruce E. A1 Tal-Singer, Ruth A1 Chalmers, James D. YR 2021 UL http://openres.ersjournals.com/content/7/4/00253-2021.abstract AB Background Breath analysis is a burgeoning field, with interest in volatile organic compounds (VOCs) as a noninvasive diagnostic tool or an outcome measure, but no randomised controlled trials (RCTs) have yet evaluated this technology in a clinical trial longitudinally. In a pilot RCT, our exploratory objectives were feasibility of measuring VOCs via multiple techniques, assessing relationships between VOCs and Haemophilus colonisation and whether CXCR2 antagonism with danirixin altered lung microbiome composition in individuals with COPD.Method 43 participants had VOCs and sputum biomarkers evaluated. VOCs and induced sputum were collected after 6 h of fasting at screening and at days 1, 7 and 14. VOCs were analysed via gas chromatography mass spectrometry (GC-MS), field asymmetric ion mobility spectrometry (FAIMS) and eNose. The primary outcome for these analyses was the relationship between VOCs and Haemophilus abundance determined by 16S rRNA sequencing.Results A joint-effects model demonstrated a modest relationship between four exhaled VOCs and Haemophilus relative abundance (R2=0.55) measured only by GC-MS, but not as measured using gas chromtaography FAIMS or eNose. There was considerable variability in absolute quantities of individual VOCs longitudinally.Conclusions VOC measurement in clinical trials to identify subsets of COPD is feasible, but assessment of new VOC technologies must include concurrent GC-MS validation. Further work to standardise collection of VOCs and measuring a background or “housekeeper” VOC is required to understand and normalise individual VOC quantities.VOC measurement in clinical trials to identify COPD subsets is feasible, but assessment of VOC technologies must include concurrent GC-MS validation. Further work to standardise collection of VOCs and measure a background or “housekeeper” VOC is required. https://bit.ly/3BNyKvS