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World J Clin Cases. Jul 26, 2023; 11(21): 4996-5013
Published online Jul 26, 2023. doi: 10.12998/wjcc.v11.i21.4996
Exhaled volatile organic compounds for diagnosis and monitoring of asthma
Luisa Savito, Simone Scarlata, Andras Bikov, Pierluigi Carratù, Giovanna Elisiana Carpagnano, Silvano Dragonieri
Luisa Savito, Simone Scarlata, Department of Internal Medicine, Unit of Respiratory Pathophysiology and Thoracic Endoscopy, Fondazione Policlinico Universitario Campus Bio Medico, Rome 00128, Italy
Andras Bikov, Wythenshawe Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, United Kingdom
Andras Bikov, Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, United Kingdom
Pierluigi Carratù, Department of Internal Medicine "A.Murri", University of Bari "Aldo Moro", Bari 70124, Italy
Giovanna Elisiana Carpagnano, Silvano Dragonieri, Department of Respiratory Diseases, University of Bari, Bari 70124, Italy
Author contributions: Savito L wrote the first draft; Scarlata S performed the supervision; Bikov A contributed to the conceptualization, english editing; Carratù P performed the data collection; Carpagnano GE conceptualization, data collection; Dragonieri S wrote the first draft and performed the supervision.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Silvano Dragonieri, MD, PhD, Associate Professor, Department of Respiratory Diseases, University of Bari, Piazza Giulio Cesare 11, Bari 70124, Italy. silvano.dragonieri@uniba.it
Received: May 17, 2023
Peer-review started: May 17, 2023
First decision: May 25, 2023
Revised: June 8, 2023
Accepted: July 6, 2023
Article in press: July 6, 2023
Published online: July 26, 2023
Processing time: 70 Days and 17.3 Hours
Abstract

The asthmatic inflammatory process results in the generation of volatile organic compounds (VOCs), which are subsequently secreted by the airways. The study of these elements through gas chromatography-mass spectrometry (GC-MS), which can identify individual molecules with a discriminatory capacity of over 85%, and electronic-Nose (e-NOSE), which is able to perform a quick onboard pattern-recognition analysis of VOCs, has allowed new prospects for non-invasive analysis of the disease in an "omics" approach. In this review, we aim to collect and compare the progress made in VOCs analysis using the two methods and their instrumental characteristics. Studies have described the potential of GC-MS and e-NOSE in a multitude of relevant aspects of the disease in both children and adults, as well as differential diagnosis between asthma and other conditions such as wheezing, cystic fibrosis, COPD, allergic rhinitis and last but not least, the accuracy of these methods compared to other diagnostic tools such as lung function, FeNO and eosinophil count. Due to significant limitations of both methods, it is still necessary to improve and standardize techniques. Currently, e-NOSE appears to be the most promising aid in clinical practice, whereas GC-MS, as the gold standard for the structural analysis of molecules, remains an essential tool in terms of research for further studies on the pathophysiologic pathways of the asthmatic inflammatory process. In conclusion, the study of VOCs through GC-MS and e-NOSE appears to hold promise for the non-invasive diagnosis, assessment, and monitoring of asthma, as well as for further research studies on the disease.

Keywords: Asthma; Volatile organic compounds; Gas chromatography-mass spectrometry; Electronic-Nose; Breathomics; Non-invasive diagnosis

Core Tip: The groundbreaking omics approach of non-invasive diagnosis of asthma by means of exhaled volatile organic compounds in several respiratory diseases, including asthma, is feasible and might revolutionize the diagnostic management of the aforementioned diseases.