Identification of Autoantigens in EGPA and Severe Eosinophilic Asthma (IDEA)

Identification of Autoantigens and Their Potential Post-translational Modification in EGPA and Severe Eosinophilic Asthma

In this project the investigators will look for auto-antibodies to relevant proteins both in native form and importantly in post-translationally modified forms. Potential modified auto-antigens are eosinophil proteins (analogous to the cytoplasmic neutrophil proteins identified in vasculitides such as Granulomatosis with Polyangiitis (formerly known as Wegener's granulomatosis) and alternatively structural proteins such as collagen V. As well as advancing the understanding of asthma pathology, identifying a serum auto-antibody that could then be used as a clinical blood test, analogous to anti-cyclic citrullinated peptide (CCP) antibodies in rheumatoid arthritis, may revolutionise diagnosis of severe eosinophilic asthma and Eosinophilic Granulomatosis with Polyangiitis (EGPA). There is a considerable burden of undiagnosed severe eosinophilic asthma in part due to difficulties in definitive diagnosis and a diagnostic blood test would help diagnose these patients, allowing them to receive necessary treatment.

Study Overview

• Status: Completed
• Conditions: Eosinophilic Esophagitis; Churg-Strauss Syndrome; Eosinophilic Asthma; Eosinophilic Pneumonia
• Intervention / Treatment: Diagnostic test: Autoantibody ELISA; Diagnostic test: Granulocyte Immunofluorescence

Detailed Description

The investigators will approach the research question with parallel agnostic and targeted approaches.

In the agnostic approach the presence of auto-antibodies in patient serum and sputum to inactive and activated eosinophils, with and without post-translational modification, will be examined by indirect immunofluorescence.

In the targeted approach the investigators will examine by enzyme-linked immunoassay (ELISA) the presence/absence of antibodies to pre-selected candidate eosinophil and base membrane proteins both in native form and post-translationally modified. Proteins to examine will be chosen based on literature review (e.g. eosinophil peroxidase and collagen V) and eosinophil-specific proteins identified by FANTOM5 (Functional Annotation of the Mouse/Mammalian Genome) geneset analysis (FANTOM Consortium et al. 2014).

Both blood and sputum samples from highly-characterised patients with severe eosinophilic asthma and/or EGPA will be examined given the possibility of compartment-specific immune responses.

Once candidate auto-antigens have been identified in the selected group of patients with severe eosinophilic asthma and EGPA, the investigators will then examine their prevalence in serum samples from a wider selection of patients with eosinophilic airways diseases including mild-to-moderate asthma, severe eosinophilic asthma, EGPA, nasal polyposis and eosinophilic chronic obstructive pulmonary disease (COPD) as well as healthy controls. Length of disease, atopy, presence/absence nasal polyps, gender, age will be examined as co-variates. Correlations with highest blood eosinophil counts, requirement for oral corticosteroids and presence of other auto-antibodies, e.g. anti-MPO (myeloperoxidase) ANCA (anti-neutrophil cytoplasmic antibody), will be examined. In particular the investigators will look for the presence of novel autoantibodies in specific patient subsets: i) ANCA negative, ii) ANCA positive by immunofluorescence but negative for anti-MPO and anti-PR3 (proteinase-3) antibodies, iii) ANA (anti-nuclear antibody) positive but ANCA and extractable nuclear antigen (ENA) negative; since patients in all three groups may have novel, as yet undetermined autoantibodies. ROC (receiver operator characteristic curve) AUC (area under curve) analyses will be conducted to ascertain the predictive value of blood auto-antibodies for diagnosis of eosinophilic airways disease.

• Study Type: Observational
• Enrollment (Actual): 120

Contacts and Locations

Study Locations

• United Kingdom
  • London, United Kingdom, E1 4DG
    • Barts Health NHS Trust, Dept of Rheumatology, Mile End Hospital
  • London, United Kingdom, EC1A 7BE
    • Barts Health NHS Trust, Dept of Respiratory Medicine, St Bartholomew's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

Patients will be recruited via Outpatient Clinics conducted at St Bartholomew's (Bart's) Hospital, The Royal London Hospital, and Mile End Hospital (all Bart's Health NHS Trust), as well as from inpatients at these hospitals under the care of the Respiratory Medicine and Rheumatology teams (including those under other services needing inpatient respiratory medicine or rheumatology review).

Description

Inclusion Criteria:

• Severe Eosinophilic Asthma (with multi-disciplinary diagnosis as per ERS/ATS Criteria, blood eosinophils ≥ 0.3 x109/L on inhaled corticosteroids); or
• EGPA (as per American College of Rheumatology (ACR) Criteria); or
• Eosinophilic COPD (post-bronchodilator FEV1/FVC < 70% predicted, absence of bronchodilator reversibility, > 20 pack year smoking history, no history of asthma, blood eosinophils ≥ 0.3 x109/L); or
• Eosinophilic oesophagitis (with diagnostic histology); or
• Granulomatosis with Polyangiitis (GPA, formerly called Wegener's) (as per American College of Rheumatology (ACR) Criteria)

Exclusion Criteria:

• Known Pregnancy
• Anaemia
• Hepatitis B Virus, Hepatitis C Virus or HIV infection
• Donation of more than 240mls blood in the last sixteen weeks (four months) to any other research study or as a donation to the National Blood Transfusion Service
• Rituximab, plasmapharesis or polyclonal immunoglobulin infusion (ever)

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Prospective

Number of groups / cohorts

4

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Other respiratory conditions; Milder asthma, other vasculitides, eosinophilic COPD, and/or eosinophilic oesophagitis	Diagnostic test: Autoantibody ELISA; Serum will be tested for novel autoantibodies against candidate auto-antigens by ELISA, such as those previously identified as of importance (e.g. eosinophil peroxidase, EPX) and also novel candidate proteins specific to eosinophils as identified by FANTOM5 geneset analysis.; Diagnostic test: Granulocyte Immunofluorescence; The presence of auto-antibodies in patient serum to inactive and activated neutrophils / eosinophils, with and without post-translational modification, will be examined by indirect immunofluorescence.
Severe eosinophilic asthma; Patients with eosinophilic asthma meeting ERS/ATS criteria for severe asthma.	Diagnostic test: Autoantibody ELISA; Serum will be tested for novel autoantibodies against candidate auto-antigens by ELISA, such as those previously identified as of importance (e.g. eosinophil peroxidase, EPX) and also novel candidate proteins specific to eosinophils as identified by FANTOM5 geneset analysis.; Diagnostic test: Granulocyte Immunofluorescence; The presence of auto-antibodies in patient serum to inactive and activated neutrophils / eosinophils, with and without post-translational modification, will be examined by indirect immunofluorescence.
Healthy controls; Healthy patients with no chronic lung condition.	Diagnostic test: Autoantibody ELISA; Serum will be tested for novel autoantibodies against candidate auto-antigens by ELISA, such as those previously identified as of importance (e.g. eosinophil peroxidase, EPX) and also novel candidate proteins specific to eosinophils as identified by FANTOM5 geneset analysis.; Diagnostic test: Granulocyte Immunofluorescence; The presence of auto-antibodies in patient serum to inactive and activated neutrophils / eosinophils, with and without post-translational modification, will be examined by indirect immunofluorescence.
EGPA; Patients with asthma meeting criteria for a diagnosis of EGPA (eosinophilic granulomatosis with polyangiitis) as per Wechsler et al. [N Engl J Med. 2017 May 18;376(20):1921-1932]	Diagnostic test: Autoantibody ELISA; Serum will be tested for novel autoantibodies against candidate auto-antigens by ELISA, such as those previously identified as of importance (e.g. eosinophil peroxidase, EPX) and also novel candidate proteins specific to eosinophils as identified by FANTOM5 geneset analysis.; Diagnostic test: Granulocyte Immunofluorescence; The presence of auto-antibodies in patient serum to inactive and activated neutrophils / eosinophils, with and without post-translational modification, will be examined by indirect immunofluorescence.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number and Percentage of Patients With a Positive Autoantibody ELISA	Serum tested for novel autoantibodies against candidate auto-antigens by ELISA. Outcome: Positive OD by ELISA (serum samples) to autoantigen panel (MPO, Collagen V, TREM1, IL1R2).	Baseline, at study entry

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number and Percentage of Patients With Positive Granulocyte Immunofluorescence	FITC anti-IgG immunofluorescence with slides of unstimulated/PMA-stimulated neutrophils (serum samples)	Baseline, at study entry

Collaborators and Investigators

• Sponsor: Queen Mary University of London
• Investigators: Study Chair: Myles J Lewis, MD PhD FRCP, Queen Mary University of London; Principal Investigator: Paul Pfeffer, MD, Barts & The London NHS Trust

Study record dates

Study Major Dates

• Study Start (Actual): December 10, 2020
• Primary Completion (Actual): October 12, 2022
• Study Completion (Actual): May 5, 2024

Study Registration Dates

• First Submitted: October 26, 2020
• First Submitted That Met QC Criteria: December 10, 2020
• First Posted (Actual): December 17, 2020

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: December 20, 2024
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Autoimmune Diseases; Immune System Diseases; Respiratory Tract Diseases; Digestive System Diseases; Gastrointestinal Diseases; Lung Diseases; Bronchial Diseases; Lung Diseases, Obstructive; Respiratory Hypersensitivity; Hypersensitivity, Immediate; Hypersensitivity; Hypereosinophilic Syndrome; Eosinophilia; Leukocyte Disorders; Hematologic Diseases; Esophageal Diseases; Skin Diseases; Gastroenteritis; Lymphatic Diseases; Lymphoproliferative Disorders; Skin Diseases, Vascular; Vasculitis; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Granuloma; Systemic Vasculitis; Asthma; Pulmonary Eosinophilia; Esophagitis; Churg-Strauss Syndrome; Eosinophilic Esophagitis; Immunologic Factors; Physiological Effects of Drugs; Autoantibodies
• Other Study ID Numbers: IRAS 274097; 20/PR/0004 (Other Identifier: Health Research Authority)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No