Exhaled volatile organic compounds discriminate patients with chronic obstructive pulmonary disease from healthy subjects

Abstract

Vasiliki Besa,1 Helmut Teschler,2 Isabella Kurth,1 Amir Maqbul Khan,3 Paul Zarogoulidis,4 Joerg Ingo Baumbach,5 Urte Sommerwerck,2 Lutz Freitag,1 Kaid Darwiche1 1Department of Interventional Pneumology, Ruhrlandklinik, West German Lung Center, University Hospital, University Duisburg-Essen, Essen, Germany; 2Department of Pneumology, Ruhrlandklinik, University Hospital Essen, University of Essen-Duisburg, Essen, Germany; 3Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, ON, Canada; 4Oncology Unit, Pulmonary Department, “G Papanikolaou” General Hospital, Aristotle University of Thessaloniki, Greece; 5Faculty of Applied Chemistry, Reutlingen University, Reutlingen, Germany Abstract: Chronic obstructive pulmonary disease (COPD) is a chronic airway inflammatory disease characterized by incompletely reversible airway obstruction. This clinically heterogeneous group of patients is characterized by different phenotypes. Spirometry and clinical parameters, such as severity of dyspnea and exacerbation frequency, are used to diagnose and assess the severity of COPD. The purpose of this study was to investigate whether volatile organic compounds (VOCs) could be detected in the exhaled breath of patients with COPD and whether these VOCs could distinguish COPD patients from healthy subjects. Moreover, we aimed to investigate whether VOCs could be used as biomarkers for classifying patients into different subgroups of the disease. Ion mobility spectrometry was used to detect VOCs in the exhaled breath of COPD patients. One hundred and thirty-seven peaks were found to have a statistically significant difference between the COPD group and the combined healthy smokers and nonsmoker group. Six of these VOCs were found to correctly discriminate COPD patients from healthy controls with an accuracy of 70%. Only 15 peaks were found to be statistically different between healthy smokers and healthy nonsmokers. Furthermore, by determining the cutoff levels for each VOC peak, it was possible to classify the COPD patients into breathprint subgroups. Forced expiratory volume in 1 second, body mass index, and C-reactive protein seem to play a role in the discrepancies observed in the different breathprint subgroups. Keywords: breath analysis, COPD, ion mobility spectrometry, volatile organic compounds