- Conference Article
- 10.1183/13993003.congress-2025.pa1505
Raised blood eosinophil counts are associated with high airway type 2 inflammation in chronic obstructive pulmonary disease
- Sep 27, 2025
- Sudarshan Chari + 5 more +5
<bold>Background:</bold> Type 2 inflammation and eosinophils can promote chronic obstructive pulmonary disease (COPD) pathophysiology and increase the risk of exacerbations. <bold>Aims:</bold> To assess the association between type 2 inflammation gene signatures and clinical and phenotypic biomarkers. <bold>Methods:</bold> ECLIPSE (<ext-link>NCT00292552</ext-link>) was a longitudinal, observational study of patients with COPD, a baseline post-bronchodilator (BD) forced expiratory volume in 1 second (FEV<sub>1</sub>) <80% predicted, and baseline post-BD FEV<sub>1</sub>/forced vital capacity ≤0.7. A type 2 gene set signature (24 genes) was assessed by microarray-based transcriptomics. Gene set variation analysis (GSVA) scores for the gene set signature in each patient were calculated. Analysis 1 assessed GSVA score association with sputum and blood eosinophil count (BEC) using Spearman’s correlation and linear models. Analysis 2 assessed sputum GSVA score association with sputum eosinophil count. <bold>Results:</bold> Analysis 1 included 112 samples with paired sputum and BEC. Type 2 GSVA score was associated with sputum eosinophils (≥2% or <2%) and with BEC distribution subgroups (<100, 100–299, and ≥300 cells/μL). Analysis 2 included 143 sputum samples. Type 2 GSVA score in sputum cell gene expression activities was positively associated with both BEC levels and sputum eosinophil counts. These positive associations persisted when GOLD E patients were excluded. <bold>Conclusions:</bold> Raised BEC is associated with increased type 2 inflammation gene expression in COPD sputum, suggesting anti-interleukin-5 therapy may reduce exacerbations. The findings also suggest a widely shared pathological feature in COPD, regardless of GOLD grade. <bold>Funding:</bold> GSK (104960).
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