Breathomics for the clinician: the use of volatile organic compounds in respiratory diseases

Abstract

Exhaled breath analysis has the potential to provide valuable insight on the status of various metabolic pathways taking place in the lungs locally and other vital organs, via systemic circulation. For years, volatile organic compounds (VOCs) have been proposed as feasible alternative diagnostic and prognostic biomarkers for different respiratory pathologies.We reviewed the currently published literature on the discovery of exhaled breath VOCs and their utilisation in various respiratory diseasesKey barriers in the development of clinical breath tests include the lack of unified consensus for breath collection and analysis and the complexity of understanding the relationship between the exhaled VOCs and the underlying metabolic pathways. We present a comprehensive overview, in light of published literature and our experience from coordinating a national breathomics centre, of the progress made to date and some of the key challenges in the field and ways to overcome them. We particularly focus on the relevance of breathomics to clinicians and the valuable insights it adds to diagnostics and disease monitoring.Breathomics holds great promise and our findings merit further large-scale multicentre diagnostic studies using standardised protocols to help position this novel technology at the centre of respiratory disease diagnostics.

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

“…Volatile organic compounds (VOCs) have the potential to mirror various metabolic processes both locally within the respiratory system and systemically, via blood circulation [6,7]. VOCs have been utilised as diagnostic, prognostic and treatment response biomarkers for various respiratory illness, including infections [8][9][10][11][12]. The rapid, cost effective and non-invasive nature make VOCs a strong candidate as a potential COVID-19 biomarkers, substantiated by preliminary studies highlighting its diagnostic potential [13,14].…”

Breathing Rhythm Variations during Wash-In Do Not Influence Exhaled Volatile Organic Compound Profile Analyzed by an Electronic Nose

“…How can we explain our results? Human-exhaled breath contains over 3000 VOCs deriving from physiologic and pathophysiological mechanisms, operating via metabolic pathways [ 15 ]. In accordance with the findings of previous studies, our results suggest that, although breathing rhythm modifies the individual components of exhaled breath, the overall VOC profile, as measured by an e-nose, does not differ among groups with different breathing rhythms.…”

Iškvepiamųjų Metabolitų Diagnostinis Potencialas

“…Šiuo metu nustatyta keletas tūkstančių skirtingų LOJ. Organizme jie išskiriami mažais kiekiais ir gali būti matuojami milijoninėmis ar milijardinėmis dalimis (parts per million -ppm, parts per billion -ppb) [2]. Susidomėjimas LOJ potencialu ligų diagnostikoje vis didėja, tad tikėtina, kad greitu metu šių biožymenų naudojimas nustatant plaučių ligas bus vis prieinamesnis.…”

“…Egzogeniniai LOJ gali būti įkvepiami, patekti į organizmą per odą ar susintetinti vietinės mikrobiotos. Šios rūšies biožymenys padėtų nustatyti infekcijų sukėlėjų rūšį ar sukėlusią medžiagą greičiau, nei kitais diagnostikos metodais [2).…”