Neutrophilic inflammation in sputum or blood does not define a clinically distinct asthma phenotype in ATLANTIS
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Introduction
Neutrophilic asthma has been suggested to be a clinically distinct phenotype characterised by more severe airflow obstruction and higher exacerbation risk. However, this has only been assessed in few and smaller studies, using different cut-offs to define neutrophilia, and with conflicting results. We used data from ATLANTIS, an observational longitudinal study including a large number of patients with asthma and healthy controls. The aim of the present study was to examine whether neutrophilic inflammation, either in sputum or blood, is more prevalent in asthma and whether it correlates with disease severity.
Methods
ATLANTIS included 773 asthma patients, with blood collected from 767 (99%) and sputum from 228 patients (30%). Data were available from 244 healthy controls, all providing blood and 126 (52%) providing sputum. Asthma patients were characterised, including parameters of large and small airways disease at baseline and after 6 and 12 months of follow-up. Sputum and blood neutrophilia were defined as values exceeding the upper quartile in asthma patients.
Results
The prevalence of sputum neutrophilia did not differ between asthma patients and healthy controls. Asthma patients with sputum neutrophilia did not display more severe symptoms, large or small airways disease or more frequent exacerbations. Blood neutrophilia was more common in asthma and was associated with higher body mass index, female sex, current smoking and systemic corticosteroid use. Patients with blood neutrophilia had a statistically significant, but small, increase in residual volume/total lung capacity. Blood neutrophilia was not associated with large or small airways disease or exacerbation risk.
Conclusion
Sputum and blood neutrophilia do not define a distinct clinical phenotype in asthma.
Neutrophilic asthma has been suggested to be a clinically distinct phenotype characterised by more severe airflow obstruction and higher exacerbation risk. However, this has only been assessed in few and smaller studies, using different cut-offs to define neutrophilia, and with conflicting results. We used data from ATLANTIS, an observational longitudinal study including a large number of patients with asthma and healthy controls. The aim of the present study was to examine whether neutrophilic inflammation, either in sputum or blood, is more prevalent in asthma and whether it correlates with disease severity.
Methods
ATLANTIS included 773 asthma patients, with blood collected from 767 (99%) and sputum from 228 patients (30%). Data were available from 244 healthy controls, all providing blood and 126 (52%) providing sputum. Asthma patients were characterised, including parameters of large and small airways disease at baseline and after 6 and 12 months of follow-up. Sputum and blood neutrophilia were defined as values exceeding the upper quartile in asthma patients.
Results
The prevalence of sputum neutrophilia did not differ between asthma patients and healthy controls. Asthma patients with sputum neutrophilia did not display more severe symptoms, large or small airways disease or more frequent exacerbations. Blood neutrophilia was more common in asthma and was associated with higher body mass index, female sex, current smoking and systemic corticosteroid use. Patients with blood neutrophilia had a statistically significant, but small, increase in residual volume/total lung capacity. Blood neutrophilia was not associated with large or small airways disease or exacerbation risk.
Conclusion
Sputum and blood neutrophilia do not define a distinct clinical phenotype in asthma.
Date Issued
2025-01-01
Date Acceptance
2024-09-01
Citation
ERJ Open Research, 2025, 11 (1), pp.00616-2024
ISSN
2312-0541
Publisher
European Respiratory Society (ERS)
Start Page
00616
End Page
2024
Journal / Book Title
ERJ Open Research
Volume
11
Issue
1
Copyright Statement
©The authors 2025 This version is distributed under the terms of the Creative Commons Attribution Non Commercial Licence 4.0. For commercial reproduction rights and permissions contact permissions@ersnet.org
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/39963164
PII: 00616-2024
Publication Status
Published
Coverage Spatial
England
Date Publish Online
2025-02-17