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Review
. 2023 Aug 1:14:20406223231190480.
doi: 10.1177/20406223231190480. eCollection 2023.

Fractional nitric oxide measurement in exhaled air (FeNO): perspectives in the management of respiratory diseases

Beatrice Ragnoli  1 , Alessandro Radaeli  2 , Patrizia Pochetti  1 , Stefano Kette  1 , Jaymin Morjaria  3 , Mario Malerba  1   4
Affiliations
Review

Fractional nitric oxide measurement in exhaled air (FeNO): perspectives in the management of respiratory diseases

Beatrice Ragnoli et al. Ther Adv Chronic Dis. .

Abstract

Exhaled nitric oxide (NO) production, upregulated by inflammatory cytokines and mediators in central and peripheral airways, can be easily and non-invasively detected in exhaled air in asthma and other respiratory conditions as a promising tool for disease monitoring. The American Thoracic Society and European Respiratory Society released recommendations that standardize the measurement of the fractional exhaled NO (FeNO). In asthma, increased FeNO reflects eosinophilic-mediated inflammatory pathways and, as a biomarker of T2 inflammation can be used to identify asthma T2 phenotype. In this setting its measurement has shown to be an important tool especially in the diagnostic process, in the assessment and evaluation of poor adherence or predicting positive response to inhaled corticosteroids treatment, in phenotyping severe asthma patients and as a biomarker to predict the response to biologic treatments. The discovery of the role of NO in the pathogenesis of different diseases affecting the airways and the possibility to estimate the predominant site of increased NO production has provided new insight on its regulatory role in the airways, making it suitable for a potential extended use in clinical practice for different pulmonary diseases, even though its role remains less clear than in asthma. Monitoring FeNO in pulmonary obstructive lung diseases including chronic bronchitis and emphysema, interstitial lung diseases, obstructive sleep apnea and other pulmonary diseases is still under debate but has opened up a window to the role NO may play in the management of these diseases. The use of FeNO is reliable, cost effective and recommendable in both adults and children, and should be implemented in the management of patients with asthma and other respiratory conditions.

Keywords: asthma management; central and peripheral airways; fractional exhaled nitric oxide; respiratory diseases.

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Conflict of interest statement

Jaymin Morjaria has received honoraria for speaking and financial support to attend meetings/advisory boards from Wyeth, Chiesi, Pfizer, MSD, Boehringer Ingelheim, Teva, GSK/Allen & Hanburys, Napp, Almirall, AstraZeneca, Trudell, Cook Medical, Medela AG, Medtronics and Novartis. He has been an expert witness in a court case relating to the impact of smoking on illness severity, ITU admissions and mortality from Covid-19 in South Africa in 2020. The entire proceeds of the work were donated to multiple charities. Mario Malerba has received honoraria for speaking and financial support for attending meetings and/or serving on the advisory boards from Chiesi, Astra-Zeneca, GSK, Laboratori Guidotti, Boehringer Ingelheim, Vitalaire, Grifols, CLS Behring. All the authors have no other relevant affiliations of financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. Jaymin Morjaria is also an Associate Editor of Therapeutic Advances in Chronic Disease; therefore, the peer-review process was managed by alternative members of the Board, and he had no involvement in the decision-making process. Beatrice Ragnoli and Mario Malerba are members of the Editorial Board of Therapeutic Advances in Chronic Disease and had no involvement in the peer review process.

Figures

Figure 1.
Figure 1.
Main respiratory diseases in which fractional exhaled nitric oxide assessment may have a potential role.
Figure 2.
Figure 2.
Usefulness of fractional exhaled nitric oxide measurement in the management of asthma and severe asthma.
Figure 3.
Figure 3.
Flow diagram of treatment decisions based on fractional exhaled nitric oxide measurement at initial evaluation of patients with suspected asthma.
See this image and copyright information in PMC

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