Identifying Unique Pathogenic Macrophages in Systemic Sclerosis-ILD

Study Overview
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Brief Summary
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Alveolar macrophages isolated from bronchoalveolar lavage (BAL) fluid from systemic sclerosis (SSc) patients with clinically significant lung fibrosis will be studied at baseline and at 6 months after enrollment to assess longitudinally the presence and persistence of an emergent, pro-fibrotic alveolar macrophage population, using single cell RNA-Seq technology to measure the individual transcriptome from each cell.

Detailed Description
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Using cutting-edge single cell RNA-Seq technology, we will identify in the BAL fluid of subjects of SSc-ILD emerging pathogenic cell populations in the lung that were previously unrecognized using standard RNA-Seq and microarray technologies, which lack the resolution to analyze transcriptomes of individual cells. Alveolar macrophages isolated from bronchoalveolar lavage (BAL) fluid from SSc patients with clinically significant lung fibrosis will be studied at baseline and at 6 months after enrollment to assess longitudinally the presence and persistence of an emergent, pro-fibrotic alveolar macrophage population. Subjects with SSc-ILD will be recruited from the Scleroderma Program. We will recruit adults who fulfill 2013 American College of Rheumatology (ACR) SSc criteria and clinically relevant SSc-interstitial lung disease. Patients will undergo bronchoscopy with bronchoalveolar lavage at month 0 and then at month 6. Healthy control subjects will complete demographic and basic medical forms to ensure health. Pertinent clinical data will be downloaded from the Enterprise Data Warehouse, an electronic database in use at Northwestern that was designed to aggregate and store patient data from various medical systems, or through manual chart review, and entered into a RedCap database created specifically for this project. During an elective bronchoscopy procedure in SSc and healthy control subjects the bronchoscope will be wedged into an affected lung segment guided by CT scanning. After wedging the bronchoscope, 120ml of sterile 0.09% normal saline will be instilled. All subsequent aliquots will be pooled. Up to 40-60 mL of BAL fluid will be obtained for analysis during each sampling. Alveolar macrophages will be sorted on a fluorescence-activated cell sorter (FACS) Aria III instrument. High-throughput single cell transcriptomic (Drop-seq) data will be processed on Northwestern high-performance computational cluster using Cell Ranger pipeline and post-processed using modified AltAnalyze pipeline.

Official Title
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Identifying Unique Pathogenic Macrophages in Systemic Sclerosis-ILD Using High Throughput Single-cell RNA-Seq

Conditions
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Fibrosis Lung, Systemic Sclerosis

Intervention / Treatment
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* Diagnostic Test: Bronchoscopy with lavage


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: meet 2013 ACR criteria for diagnosis of SSc have radiographic evidence for ILD and a forced vital capacity <70% on PFT have not taken immune suppression in the last 2 months OR have taken a stable dose of mycophenolate mofetil, rituximab, or prednisone less than or equal to 10 mg for at least 6 months Exclusion Criteria: diagnosis of an overlap syndrome, such as lupus or rheumatoid arthritis unable to provide informed consent in English currently pregnant or nursing current smoker or former smoker (greater than 10 pack years) leukopenia anemia comorbidities of uncontrolled congestive heart failure, cancer not in remission, HIV, or chronic liver disease known or suspected infection in the past 3 months BMI greater than or equal to 30 kg/m2

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| SSc-ILD<br>SSc-ILD subjects will be defined by those who fulfill 2013 American College of Rheumatology SSc criteria and have forearm modified Rodnan skin scores (mRSS) ≥1 (a validated, semi-quantitative scoring system for dermal fibrosis) and clinically relevant SSc-interstitial lung disease (ILD). A subject will be defined as having ILD if they have radiographic evidence for ILD and a forced vital capacity <70% on pulmonary function test (PFT). | Diagnostic Test: Bronchoscopy with lavage<br>* During an elective bronchoscopy procedure, the bronchoscope will be wedged into an affected lung segment guided by CT scanning. When involved an anterior segment will be used to maximize return. After wedging the bronchoscope, 120ml of sterile 0.09% normal saline will be instilled. Up to 40-60 mL of BAL fluid will be obtained for analysis during each sampling.<br>|
| Control<br>Healthy control subjects recruited from the Northwestern community will complete demographic and basic medical forms to ensure health | Diagnostic Test: Bronchoscopy with lavage<br>* During an elective bronchoscopy procedure, the bronchoscope will be wedged into an affected lung segment guided by CT scanning. When involved an anterior segment will be used to maximize return. After wedging the bronchoscope, 120ml of sterile 0.09% normal saline will be instilled. Up to 40-60 mL of BAL fluid will be obtained for analysis during each sampling.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Single-cell RNA-seq analysis | Change in alveolar macrophage transcriptome at 6 months, as measured by single cell RNA-sequencing | Baseline and 6 months |