The Influence of Mepolizumab on Structural and Inflammatory Cells in Severe Eosinophilic Asthma

Study Overview
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Brief Summary
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The IRIS study aims to investigate the way Mepolizumab affects the structure of the airway cells in patients with Severe Eosinophilic Asthma and how the immune function of these cells changes with treatment. The aim is to take samples of cells from the airways before starting Mepolizumab and after 6 months of treatment. These samples will be taken during a bronchoscopy (a camera test looking into the lungs) and we will analyse these cells in the laboratory. These investigations will allow us to better understand how Mepolizumab affects the cells within the airways.

Detailed Description
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IRIS is a prospective observational study investigating Mepolizumab in the treatment of severe eosinophilic asthma. Eosinophilic airway inflammation has been implicated in the pathogenesis of asthma and is particularly relevant in severe eosinophilic asthma (SEA), in which standard asthma therapies fail to adequately control the disease. In severe asthma, there is bronchial epithelial damage and loss of tight junction integrity, goblet cell hyperplasia, enhanced collagen generation within the airway wall and impaired innate immune responses. Mepolizumab has been shown to reduce exacerbations and improve disease control in SEA but there are no studies assessing the impact of Mepolizumab on structural airway cell activity and function and airway remodelling processes. Primary Objective: To investigate changes within bronchial epithelial cells following completion of 6 months (7 doses) of Mepolizumab using single cell RNA sequencing (scRNA-seq) and Frac-seq (subcellular fractionation and RNA-sequencing). Secondary Objectives: To investigate the following after completing treatment with 6 months of Mepolizumab: i) Changes in epithelial barrier integrity using Frac-seq, transepithelial resistance ii) Changes in epithelial antiviral responses fusing Frac-seq in unstimulated and virus-infected cells. iii) Changes in airway remodelling by assessing the profile of fibroblasts isolated from bronchial biopsies employing Frac-seq and immunostaining of bronchial biopsies iv) Evaluate the impact on peripheral airways by obtaining bronchoalveolar lavage (BAL) and peripheral airway brushings for Frac-seq analysis and protein analysis v) Peripheral airway dysfunction using impulse oscillometry Exploratory Objectives i) Evaluation of neural structural changes using biopsies

Official Title
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The Influence of Mepolizumab on Structural and Inflammatory Cells in Severe Eosinophilic Asthma

Conditions
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Asthma; Eosinophilic

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of Severe Eosinophilic Asthma (as per Southampton Severe Asthma MDT and based on ATS/ERS consensus criteria) Approved for treatment with Mepolizumab by Southampton Severe Asthma MDT (in accordance with NICE TA 431) Blood eosinophil count is ≥0.3 x109cells/L in preceding 12 months ≥4 asthma exacerbations needing systemic steroids in the preceding 12 months Age ≥18 years Able to provide written informed consent Exclusion Criteria: On maintenance daily oral steroids, asthma immune modulators On long-term systemic antibiotics or antifungal treatment Current smoker or ex-smoker with >10 pack year smoking history Known clinically significant respiratory disorder such as bronchiectasis, interstitial lung disease, allergic bronchopulmonary aspergillosis Currently pregnant or planning pregnancy within the treatment period or breast-feeding History of psychiatric, medical or surgical disorders that in the opinion of the chief investigator may interfere with undergoing a bronchoscopy or may compromise study completion or data collection Current malignancy Alcohol or recreational drug abuse Diagnosis of immunodeficiency requiring treatment Previous bronchial thermoplasty Previous treatment with biological therapy Previously unable to tolerate a bronchoscopy Current or recent (within the last 12 weeks) infection with SARS-CoV-2 Unable to provide written informed consent

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To investigate molecular changes in the bronchial epithelium that occurs with mepolizumab treatment using RNA sequencing | Changes at the level of single cell RNA sequencing will be reported as: Changes in the percentage of cell populations present in the airways Normalised gene counts | 36 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in epithelial barrier integrity using transepithelial resistance | Transepithelial resistance measures changes in voltage across the epithelial cells | 36 months | 
| Changes in epithelial antiviral responses using interferon and other antiviral gene measurements | Gene expression will be measured using RNA sequencing and reported as gene counts | 36 months | 
| Changes in airway remodelling by assessing fibroblasts isolated from bronchial biopsies using RNA sequencing | RNA sequencing will be reported as gene counts | 36 months | 
| Changes in airway remodelling by assessing fibroblasts isolated from bronchial biopsies using immunostaining | Immunostaining will be reported as mean fluorescence intensity and percentage of cells stained | 36 months | 
| Evaluate the impact of Mepolizumab on peripheral airways by obtaining bronchoalveolar lavage for RNA sequencing | RNA sequencing will be reported as gene counts | 36 months | 
| Evaluate the impact on peripheral airways by obtaining peripheral airway brushings for RNA sequencing | RNA sequencing will be reported as gene counts | 36 months | 
| Peripheral airway dysfunction using impulse oscillometry | Impulse oscillometry will be measured as resistance and impedance | 36 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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asthma, mepolizumab, eosinophil