Abstract
Background: Exhaled nitric oxide (FENO) is used as a marker of type-2 (T2) airway inflammation in asthma management. Using allergenic airway challenge, we showed that bronchoconstriction, particularly when it occurs in peripheral airways, reduces FENO values and may fully abrogate its ability to reflect T2 inflammation (Haccuria et al. JACI 2014).
Objective: To evaluate the impact of airway calibre reduction on FENO values in a cohort of asthma patients.
Methods: In this post-hoc analysis, FENO, lung function and asthma control questionnaire (ACQ) score were recorded in 66 (461 visits) and 45 (608 visits) adult patients suffering from mild-moderate and severe asthma respectively. The relationship between individual mean log-transformed FENO and mean airway calibre, assessed by pre-bronchodilation FEV1 and residual volume (RV), was evaluated by correlation analysis.
Results: Table 1 presents Pearson correlation coefficients (p-value) between log-transformed FENO and FEV1, RV and ACQ score
Discussion: A reduction in airway calibre leads to lower FENO values in asthma patients, independently from the level of asthma control, and therefore probably from the level of airway inflammation, in a different way according to asthma severity. In mild-moderate asthma, FENO reduction is related to FEV1 reduction while in severe asthma, FENO reduction is associated with increased RV, highlighting the involvement of small airways in the latter condition. Our results suggest that a reduced airway caliber can affect FENO and therefore FENO’s value as an indicator of T2 inflammation in asthma.
Footnotes
Cite this article as Eur Respir J 2022; 60: Suppl. 66, 2847.
This article was presented at the 2022 ERS International Congress, in session “-”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2022
