PT  - JOURNAL ARTICLE
AU  - N. Fens
AU  - S.B. de Nijs
AU  - S. Peters
AU  - T. Dekker
AU  - H.H. Knobel
AU  - T.J. Vink
AU  - N.P. Willard
AU  - A.H. Zwinderman
AU  - F.H Krouwels
AU  - H-G. Janssen
AU  - R. Lutter
AU  - P.J. Sterk
TI  - Exhaled air molecular profiling in relation to inflammatory subtype and activity in COPD
AID  - 10.1183/09031936.00032911
DP  - 2011 Jan 01
TA  - European Respiratory Journal
PG  - erj00329-2011
4099  - http://erj.ersjournals.com/content/early/2011/06/20/09031936.00032911.short
4100  - http://erj.ersjournals.com/content/early/2011/06/20/09031936.00032911.full
AB  - Eosinophilic inflammation in COPD is predictive for responses to inhaled steroids. We hypothesized that inflammatory subtype in mild and moderate COPD can be assessed by exhaled breath metabolomics.Exhaled compounds were analysed using gas-chromatography and mass-spectrometry (GC-MS) and electronic nose (eNose) in 28 COPD patients (12/16 GOLD I/II). Differential cell counts, ECP and MPO were measured in induced sputum. Relationships between exhaled compounds, eNose breathprints and sputum inflammatory markers were analysed and ROC curves were constructed.Exhaled compounds were highly associated with sputum cell counts (8 compounds with eosinophils, 17 with neutrophils: p<0.01). Only one compound (alkylated benzene) overlapped between eosinophilic and neutrophilic profiles. GC-MS and eNose breathprints were associated with markers of inflammatory activity in GOLD stage I (ECP: 19 compounds, p<0.01; eNose breathprint r=0.84, p=0.002) (MPO: 4 compounds p<0.01; eNose r=0.72, p=0.008). ROC analysis for eNose showed high sensitivity and specificity for inflammatory activity in mild COPD (ECP: AUC=1.00) (MPO: AUC=0.96) but not for moderate COPD.Exhaled molecular profiles are closely associated with the type of inflammatory cell and their activation status in mild and moderate COPD. This suggests that breath analysis may be used for assessment and monitoring of airways inflammation in COPD.