Clinical, molecular and microbial characterisation of the eosinophilic endotype of bronchiectasis: data from the EMBARC-BRIDGE study
Year: 2026
Type: article
Study design: Observational Study
Abstract: Objectives Eosinophilic bronchiectasis is defined by a blood eosinophil count (BEC) ≥300 cells/µL, but blood eosinophils imperfectly reflect airway eosinophilic inflammation. Here, we investigated the relationship between eosinophilic airway inflammation, blood eosinophils and clinical severity in bronchiectasis and explored the phenotype associated with eosinophilic bronchiectasis. Methods Sputum from 180 patients with stable CT-confirmed bronchiectasis was utilised to investigate airway levels of eosinophil proteins (eosinophil peroxidase (EPX), eosinophil derived-neurotoxin (EDN), eosinophil cationic protein (ECP), major basic protein (MBP) and Galectin-10 (Gal-10)) using a novel stable isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay. To profile eosinophilic bronchiectasis, a nested analysis of patients with BEC <150 cells/µL (n=52) and ≥300 cells/µL (n=49) was conducted. Results Sputum concentrations of Gal-10, ECP and EDN were weakly but significantly associated with radiological severity, FEV 1 and sputum culture positivity for Pseudomonas aeruginosa . Airway eosinophil protein concentrations did not associate with exacerbation frequency. Total eosinophil protein concentration moderately correlated with BECs (r=0.33 95% CI 0.14 to 0.49, p=0.0007). Nested analysis revealed increased sputum PCR-positivity for P. aeruginosa (26.7% vs 7.7%, p=0.033) and an increased frequency of patients showing signs of Aspergillus sensitisation (defined as Aspergillus -specific IgE titres >0.35 kUA/L, 24.5% vs 3.8%) in eosinophilic bronchiectasis. Sputum inflammatory biomarkers and clinical parameters did not differ between groups. Conclusions LC-MS/MS can detect eosinophilic inflammation within bronchiectasis sputum. Weak associations between elevated airway eosinophil proteins, bronchiectasis severity and P. aeruginosa infection were observed. Direct measurement of eosinophilic airway inflammation provides additional information in addition to BECs. Eosinophilic bronchiectasis associated with P. aeruginosa infection and Aspergillus sensitisation.
Source: Thorax
Authors: Jennifer Pollock, Jeffrey T J Huang, Morven Shuttleworth, Merete B Long, Hollian Richardson, Daniela Alferes de Lima, Elena Kuzmanova, Clare Clarke, Michal Shteinberg, Stefano Aliberti, Charles Haworth, Sanjay Haresh Chotirmall, Eva Polverino, Pieter C Goeminne, Michael Loebinger, Natalie Lorent, Felix C Ringshausen, Oriol Sibila, Eva Rodriguez-Suarez, Christopher McCrae, Amelia Shoemark, James D Chalmers
Institutions: University of Dundee, Technion – Israel Institute of Technology, Carmel Medical Center, Humanitas University, IRCCS Humanitas Research Hospital, Royal Papworth Hospital, Nanyang Technological University, Tan Tock Seng Hospital, Vall d'Hebron Hospital Universitari, Royal Brompton Hospital, Imperial College London, Universitair Ziekenhuis Leuven, KU Leuven, German Center for Lung Research, Hospital Clínic de Barcelona, Consorci Institut D'Investigacions Biomediques August Pi I Sunyer, Universitat de Barcelona, AstraZeneca (United States), University of Oxford
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Funders: AstraZeneca UK, Pfizer, AstraZeneca, GlaxoSmithKline, Sanofi, Teva Pharmaceutical Industries, Chiesi Farmaceutici, CSL Behring, European Respiratory Society, Deutsches Zentrum für Infektionsforschung, LifeArc, European Federation of Pharmaceutical Industries and Associations, MannKind Corporation, INOVIO Pharmaceuticals, Moderna, Insmed, Asthma and Lung UK, European Commission, National Research Foundation, National Research Foundation Singapore, Deutsches Zentrum für Lungenforschung, Imam Abdulrahman Bin Faisal University, Grifols, Medical Research Council, National Medical Research Council
OpenAlex ID: W7128902971