Mechanistic Study of Epithelial miRNAs and T-cell Recruitment Dynamics That Occur After Allergen Challenge in Patients With Asthma.
试验速览
- 阶段
- 2 期
- 状态
- 已完成
- 发起方
- 入组人数
- 28
- 试验地点
- 1
- 主要终点
- Difference in Expression of Epithelial miRNAs (in Read Counts) 24 Hours After Allergen-challenge as Compared to 24 Hours After Diluent Challenge in Participants With Allergic Asthma
研究概览
简要总结
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 50 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Allergic/Non-Asthmatic subjects and Allergic/Asthmatic subjects
- •Inclusion Criteria:
- •Positive skin test to dust mite or cat allergen
- •Non-Allergic/Non-Asthmatic subjects
- •Inclusion Criteria:
- •Negative skin test to panel of 12 allergens, including dust mite and cat allergen
排除标准
- •History of intubation for asthma exacerbation
- •Use of Xolair (omalizumab) within the last 6 months
- •Immunotherapy with cat or dust mite extract now or in the past 5 years
- •≥ 10 pack-years smoking or any smoking in the past year
- •Other lung diseases, such as sarcoidosis, bronchiectasis or active lung infection
- •History of dermatographia
- •History of anaphylaxis to cat allergen
- •Participation in another research study involving a drug or biologic during the past 30 days
- •Presence of past or current medical problems/other factors that may pose additional risks from participation or influence study results, as determined per study investigator
研究组 & 干预措施
Allergen challenge subjects
Intervention: Segmental airway allergen challenge
Three types of subjects are studied in this arm:
- 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)
干预措施: Spirometry (Diagnostic Test)
Allergen challenge subjects
Intervention: Segmental airway allergen challenge
Three types of subjects are studied in this arm:
- 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)
干预措施: Allergen skin prick test (Diagnostic Test)
Allergen challenge subjects
Intervention: Segmental airway allergen challenge
Three types of subjects are studied in this arm:
- 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)
干预措施: Segmental airway allergen challenge (Biological)
Allergen challenge subjects
Intervention: Segmental airway allergen challenge
Three types of subjects are studied in this arm:
- 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)
干预措施: Bronchoscopy (Procedure)
Allergen challenge subjects
Intervention: Segmental airway allergen challenge
Three types of subjects are studied in this arm:
- 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)
干预措施: Methacholine challenge test (Diagnostic Test)
结局指标
主要结局
Difference in Expression of Epithelial miRNAs (in Read Counts) 24 Hours After Allergen-challenge as Compared to 24 Hours After Diluent Challenge in Participants With Allergic Asthma
时间窗: 24 hours
For each participant with Allergic Asthma, a baseline airway epithelial brushing was performed, allergen was instilled into one segment of the lung, and diluent (control) was instilled into another segment. Both segments were brushed for epithelial cells 24 hours later. After processing brushes to RNA and generating RNA sequencing data, the RNA transcript read counts for each gene underwent variance stabilized log normalization. Then we built a regression model which estimated the difference in miRNA read count in the allergen challenged as compared to the baseline sample and the difference in miRNA read count in the diluent challenged segment as compared to baseline for each participant. The change from baseline read count for each miRNA in the allergen samples was compared to the change in the diluent samples and statistical significance was assessed using the unadjusted p-value(\<0.05). The direction of change does not have clinical significance; this was a mechanistic study.
Difference in Expression of Epithelial miRNAs (in Read Counts) 7 Days After Allergen-challenge as Compared to 7 Days After Diluent Challenge
时间窗: 7 days
For each participant with Allergic Asthma, a baseline airway epithelial brushing was performed, allergen was instilled into one segment of the lung, and diluent (control) was instilled into another segment. Both segments were brushed for epithelial cells 7 days later. After processing the brushes to RNA and generating RNA sequencing data, the RNA transcript read counts for each gene underwent variance stabilized log normalization. Then we built a regression model which estimated the difference in miRNA read count in the allergen challenged as compared to the baseline sample and the difference in miRNA read count in the diluent challenged segment as compared to baseline for each participant. The change from baseline read count for each miRNA in the allergen samples was compared to the change in the diluent samples and statistical significance was assessed using the unadjusted p-value(\<0.05). The direction of change does not have clinical significance; this was a mechanistic study.
次要结局
未报告次要终点
研究者
Prescott Woodruff
Professor of Medicine
University of California, San Francisco