A profile of volatile organic compounds in breath discriminates COPD patients from controls
Received 16 June 2009; accepted 21 October 2009. published online 11 November 2009.
Summary
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.
Findings
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.
Interpretation
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.
aDepartment 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
bDepartment of Respiratory Medicine, University Hospital Maastricht, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands
cCentre for Integrated Rehabilitation Organ Failure (CIRO), Horn, The Netherlands
Corresponding author.
1 Present address: Department of Respiratory Medicine, Leiden University Medical Centre, Leiden, the Netherlands.
ABSTRACT