Volatile organic compounds in exhaled breath of patients with COPD ± lung cancer and their correlation with FEV1-values

Introduction Ion mobility spectrometry (MCC/IMS) is currently evaluated for exhaled breath analysis in different pulmonary diseases. The relevance of different specific volatile organic compounds (VOC) and their potential relations to FEV1 still remain unknown. We wondered if patients with COPD ± lung cancer exhale different VOCs and if there is a relation to FEV1 resp. FEV1/VC. Methods In 61 patients with COPD and lung cancer, 23 with COPD and 32 healthy controls exhaled breath was analysed with an IMS coupled to a multi capillary column (MCC/IMS). Discrimination between the subgroups was made by a decision-tree-model. Results 102 different peaks were found. 29 showed a 99 % significance level, including 2-Methylfurane, 2-Methylpentane, 1-Butanole, Butanal, Cyclohexanole, Propanal, 1-Hexanole, n-Nona, 2-Heptanole, 3-Pentanone, Phenylacetylene, 2-Butanone and Isoprene. A decision tree starting with 2-Methylpentane showed the decision power in two steps. Sensitivity of 100 % and specificity of 97 % was calculated. 3-Pentanone Dimer and 1-Hexanole differentiated the LC/COPD group from healthy control, with a specificity of 94 %. Finally, the groups COPD, LC/COPD and healthy control were differenciated using a 2-step decision tree starting with 1-Hexanole and Acetone. Correlations between analyte concentrations and FEV1 were found for the following analytes: increasing e.g. Ammonia, decreasing e.g. 1-Octanole. Conclusions Some VOCs in exhaled air of patients with COPD ± lung cancer and healthy controls allowed the separation of these group. Ffunctional impairment seems to influence the concentration of some analytes; this has to be taken into account in further analysis.