title: A profile of volatile organic compounds in breath discriminates COPD patients from controls.
abstract: BACKGROUND
  Chronic obstructive pulmonary disease (COPD) is an inflammatory condition characterized by oxidative stress and the formation of volatile organic compounds (VOCs) secreted via the lungs. We recently developed a methodological approach able to identify profiles of VOCs in breath unique for patient groups. Here we applied this recently developed methodology regarding diagnosis of COPD patients.
  
  
  METHODS
  Fifty COPD patients and 29 controls provided their breath and VOCs were analyzed by gas chromatography-mass spectrometry to identify relevant VOCs. An additional 16 COPD patients and 16 controls were sampled in order to validate the model, and 15 steroid naïve COPD patients were sampled to determine whether steroid use affects performance.
  
  
  RESULTS
  1179 different VOCs were detected, of which 13 were sufficient to correctly classify all 79 subjects. Six of these 13 VOCs classified 92% of the subjects correctly (sensitivity: 98%, specificity: 88%) and correctly classified 29 of 32 subjects (sensitivity: 100%, specificity: 81%) from the independent validation population. Fourteen out of 15 steroid naïve COPD patients were correctly classified thus excluding treatment influences.
  
  
  CONCLUSIONS
  This is the first study distinguishing COPD subjects from controls solely based on the presence of VOCs in breath. Analysis of VOCs might be highly relevant for diagnosis of COPD.
authors.affiliation: Department of Health Risk Analysis and Toxicology, Faculty of Health, Medicine and Life Sciences, Research Institute NUTRIM, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
authors.forename: J J B N
authors.initials: JJ
authors.lastname: Van Berkel
authors.forename: J W
authors.initials: JW
authors.lastname: Dallinga
authors.forename: G M
authors.initials: GM
authors.lastname: Möller
authors.forename: R W L
authors.initials: RW
authors.lastname: Godschalk
authors.forename: E J
authors.initials: EJ
authors.lastname: Moonen
authors.forename: E F M
authors.initials: EF
authors.lastname: Wouters
authors.forename: F J
authors.initials: FJ
authors.lastname: Van Schooten
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests / Q000379:methods; D016022:Case-Control Studies; D045853:Exhalation; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism; D012680:Sensitivity and Specificity; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D000305:Adrenal Cortex Hormones; D015415:Biomarkers; D055549:Volatile Organic Compounds