{
  "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.",
  "authors": [
    {
      "affiliations": [
        "University of Dundee, Dundee, UK"
      ],
      "name": "Jennifer Pollock"
    },
    {
      "affiliations": [
        "University of Dundee, Dundee, UK"
      ],
      "name": "Jeffrey T J Huang"
    },
    {
      "affiliations": [
        "University of Dundee, Dundee, UK"
      ],
      "name": "Morven Shuttleworth"
    },
    {
      "affiliations": [
        "University of Dundee, Dundee, UK"
      ],
      "name": "Merete B Long"
    },
    {
      "affiliations": [
        "University of Dundee, Dundee, UK"
      ],
      "name": "Hollian Richardson"
    },
    {
      "affiliations": [
        "University of Dundee, Dundee, UK"
      ],
      "name": "Daniela Alferes de Lima"
    },
    {
      "affiliations": [
        "University of Dundee, Dundee, UK"
      ],
      "name": "Elena Kuzmanova"
    },
    {
      "affiliations": [
        "University of Dundee, Dundee, UK"
      ],
      "name": "Clare Clarke"
    },
    {
      "affiliations": [
        "Pulmonology Institute and CF center, Carmel Medical Center, Haifa, Israel",
        "The B. Rappaport Faculty of Medicine, Technion Israel Institute of Technology, Haifa, Israel"
      ],
      "name": "Michal Shteinberg"
    },
    {
      "affiliations": [
        "Department of Biomedical Sciences, Humanitas University, Milan, Italy",
        "IRCCS Humanitas Research Hospital, Milan, Italy"
      ],
      "name": "Stefano Aliberti"
    },
    {
      "affiliations": [
        "Cambridge Centre for Lung Infection, Royal Papworth Hospital, Cambridge, UK"
      ],
      "name": "Charles Haworth"
    },
    {
      "affiliations": [
        "Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore",
        "Department of Respiratory and Critical Care Medicine, Tan Tock Seng Hospital, Singapore"
      ],
      "name": "Sanjay Haresh Chotirmall"
    },
    {
      "affiliations": [
        "Pneumology Department, Vall d’Hebron University Hospital, Barcelona, Spain"
      ],
      "name": "Eva Polverino"
    },
    {
      "affiliations": [
        "Respiratory Disease, AZ Nikolaas, Sint-Niklaas, Belgium"
      ],
      "name": "Pieter C Goeminne"
    },
    {
      "affiliations": [
        "Royal Brompton Hospital, London, UK",
        "National Heart and Lung Institute, Imperial College London, London, UK"
      ],
      "name": "Michael Loebinger"
    },
    {
      "affiliations": [
        "Department of Pneumology, University Hospital Leuven, Leuven, Belgium",
        "BREATHE laboratory, Department of Chronic Diseases and Metabolism, KU Leuven, Leuven, Belgium"
      ],
      "name": "Natalie Lorent"
    },
    {
      "affiliations": [
        "German Centre for Lung Research, Hannover, Germany"
      ],
      "name": "Felix C Ringshausen"
    },
    {
      "affiliations": [
        "Instituto Clínico de Respiratorio, IDIBAPS, Hospital Clínic, University of Barcelona, Barcelona, Spain"
      ],
      "name": "Oriol Sibila"
    },
    {
      "affiliations": [
        "Translational Science and Experimental Medicine, Early Respiratory and Immunology, AstraZeneca, Gaithersburg, Maryland, USA"
      ],
      "name": "Eva Rodriguez-Suarez"
    },
    {
      "affiliations": [
        "Translational Science and Experimental Medicine, Research and Early Development, Respiratory and Immunology, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, Maryland, USA"
      ],
      "name": "Christopher McCrae"
    },
    {
      "affiliations": [
        "University of Dundee, Dundee, UK"
      ],
      "name": "Amelia Shoemark"
    },
    {
      "affiliations": [
        "University of Dundee, Dundee, UK",
        "Radcliffe Department of Medicine, University of Oxford, Oxford, UK"
      ],
      "name": "James D Chalmers"
    }
  ],
  "title": "Clinical, molecular and microbial characterisation of the eosinophilic endotype of bronchiectasis: data from the EMBARC-BRIDGE study",
  "uid": "f2c58e56-e39e-570c-b397-dce3d505a43b"
}