Prescott Woodruff
Prescott Woodruff
This protocol describes a single site mechanistic study to investigate microRNAs (miRNAs) that are differentially expressed in the airway epithelium of patients with asthma at baseline and in response to allergen challenge. We hypothesize that allergen exposure enhances airway smooth muscle contractility and epithelial cell mRNA/miRNA production as a consequence of locally increased T-cell derived cytokine production. The study will involve three visits over the course of approximately 14 days. At Visit 1, participants will be characterized in detail with lung function testing, methacholine challenge testing, and allergen skin prick testing. At Visit 2, participants will undergo bronchoscopy with segmental allergen administration of either cat or dust mite standardized allergen extract. At Visit 3 (either 24 hours later or 7 days later), bronchoscopy will be performed to collect airway samples including bronchoalveolar lavage (BAL), epithelial brushings and endobronchial biopsies. Sample analysis will include measurement of miRNA and mRNA expression in epithelial brushings (RNAseq and qPCR); analysis of cell surface markers on BAL cells and blood cells; and collection of endobronchial biopsies for immunostaining of immune cells localization, immunoblotting of smooth cell protein phosphorylation, analysis of mucin content and smooth muscle cell subculture. A total of 38 subjects (26 asthmatics with stable or well-controlled asthma, 6 allergic non-asthmatics and 6 non-allergic non-asthmatics) will complete the study.
Asthma
Segmental airway allergen challenge
Bronchoscopy
Methacholine challenge test
Spirometry
Allergen skin prick test
Phase 2
Study Type : | Interventional |
Estimated Enrollment : | 28 participants |
Masking : | None (Open Label) |
Primary Purpose : | Basic Science |
Official Title : | Mechanistic Study of Epithelial miRNAs and T-cell Recruitment Dynamics That Occur After Allergen Challenge in Patients With Asthma. |
Actual Study Start Date : | March 2015 |
Estimated Primary Completion Date : | January 2020 |
Estimated Study Completion Date : | January 2020 |
Arm | Intervention/treatment |
---|---|
Experimental: Allergen challenge subjects Intervention: Segmental airway allergen challenge Three types of subjects are studied in this arm: 1) Volunteers with neither asthma nor allergy (as established by skin prick testing); 2) Volunteers with allergy (as established by skin prick testing) but without asthma; and 3) Volunteers with both asthma and allergy (as established by skin prick testing) |
Biological: Segmental airway allergen challenge Procedure: Bronchoscopy Diagnostic Test: Methacholine challenge test Diagnostic Test: Spirometry Diagnostic Test: Allergen skin prick test |
Ages Eligible for Study: | 18 Years to 50 Years |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Accepts Healthy Volunteers |
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Not yet recruiting
University of California, San Francisco
San Francisco, California, United States, 94143