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Published on: May 4, 2021
Airway nitric oxide output is reduced in bronchiectasis
Susan C Foley1, Natalie O Hopkins, Muiris X Fitzgerald
1School of Medicine and Medical Sciences, St. Vincent's University Hospital, Elm Park, Dublin, Ireland. susan.foley@staff.mcgill.ca
Respiratory Medicine
|January 20, 2007
Summary
In bronchiectasis patients, airway nitric oxide (NO) output is reduced, contrary to asthma findings. Chronic airway infection appears to lower NO production in the conducting airways, not the alveoli.
Area of Science:
- Pulmonary Medicine
- Respiratory Physiology
- Biomarkers of Airway Inflammation
Background:
- Exhaled nitric oxide (NO) is elevated in asthma, linked to inducible nitric oxide synthase (iNOS).
- Studies on NO in bronchiectasis show conflicting results, with some suggesting reduced production due to chronic infection.
- Animal models indicate chronic airway infection may decrease lung NO despite increased iNOS.
Purpose of the Study:
- To investigate if chronic airway infection reduces NO output from conducting airways in bronchiectasis patients.
- To determine the source of exhaled NO (conducting airways vs. alveoli) in bronchiectasis.
- To assess the effect of inhaled glucocorticoid therapy on NO production in bronchiectasis.
Main Methods:
- Utilized a two-compartment model to differentiate NO contributions from conducting airways and alveoli.
- Measured exhaled NO in nine stable bronchiectasis patients and eight controls.
- Assessed NO levels before and after high-dose inhaled glucocorticoid therapy.
Main Results:
- Airway NO output was significantly lower in bronchiectasis patients compared to controls.
- Alveolar NO output was similar between bronchiectasis patients and control subjects.
- Inhaled glucocorticoid therapy did not significantly affect airway or alveolar NO production.
Conclusions:
- Patients with bronchiectasis exhibit reduced NO output from their conducting airways.
- Inducible nitric oxide synthase (iNOS) does not appear to be a significant contributor to airway NO production in bronchiectasis.
- Airway NO levels in bronchiectasis are distinct from those observed in asthma.
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