Diagnosis of COVID-19 by exhaled breath analysis using gas chromatography-mass spectrometry

Wadah Ibrahim; Rebecca L Cordell; Michael J Wilde; Matthew Richardson; Liesl Carr; Ananga Sundari Devi Dasi; Beverley Hargadon; Robert C Free; Paul S Monks; Christopher E Brightling; Neil J Greening; Salman Siddiqui

doi:10.1183/23120541.00139-2021

Diagnosis of COVID-19 by exhaled breath analysis using gas chromatography-mass spectrometry

ERJ Open Res. 2021 Jul 5;7(3):00139-2021. doi: 10.1183/23120541.00139-2021. eCollection 2021 Jul.

Authors

Wadah Ibrahim^{1

2

3}, Rebecca L Cordell^{4

3}, Michael J Wilde⁴, Matthew Richardson^{1

2}, Liesl Carr^{1

2}, Ananga Sundari Devi Dasi^{1

2}, Beverley Hargadon^{1

2}, Robert C Free^{1

2}, Paul S Monks⁴, Christopher E Brightling^{1

2}, Neil J Greening^{1

2}, Salman Siddiqui^{1

2}

Affiliations

¹ Dept of Respiratory Sciences, University of Leicester, Leicester, UK.
² Institute for Lung Health, NIHR Leicester Biomedical Research Centre (Respiratory theme), Glenfield Hospital, Leicester, UK.
³ These authors contributed equally.
⁴ School of Chemistry, University of Leicester, Leicester, UK.

Abstract

Background: The ongoing coronavirus disease 2019 (COVID-19) pandemic has claimed over two and a half million lives worldwide so far. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is perceived to be seasonally recurrent, and a rapid noninvasive biomarker to accurately diagnose patients early on in their disease course will be necessary to meet the operational demands for COVID-19 control in the coming years.

Objective: The aim of this study was to evaluate the role of exhaled breath volatile biomarkers in identifying patients with suspected or confirmed COVID-19 infection, based on their underlying PCR status and clinical probability.

Methods: A prospective, real-world, observational study was carried out, recruiting adult patients with suspected or confirmed COVID-19 infection. Breath samples were collected using a standard breath collection bag, modified with appropriate filters to comply with local infection control recommendations, and samples were analysed using gas chromatography-mass spectrometry (TD-GC-MS).

Results: 81 patients were recruited between April 29 and July 10, 2020, of whom 52 out of 81 (64%) tested positive for COVID-19 by reverse transcription-polymerase chain reaction (RT-PCR). A regression analysis identified a set of seven exhaled breath features (benzaldehyde, 1-propanol, 3,6-methylundecane, camphene, beta-cubebene, iodobenzene and an unidentified compound) that separated PCR-positive patients with an area under the curve (AUC): 0.836, sensitivity: 68%, specificity: 85%.

Conclusions: GC-MS-detected exhaled breath biomarkers were able to identify PCR-positive COVID-19 patients. External replication of these compounds is warranted to validate these results.