Mechanisms of Ozone-Induced Alterations in Efferocytosis and Phagocytosis
试验速览
- 阶段
- 1 期
- 状态
- 已完成
- 发起方
- 入组人数
- 22
- 试验地点
- 1
- 主要终点
- Change in ozone induced phagocytosis of lung macrophages (ability to clear debris or bacteria)
研究概览
简要总结
The purpose of this research study to understand how environmental and genetic factors may be involved in lung function. Healthy Study participants will undergo a 1-day screening that includes a blood draw and breathing testing, return for a two-day series of testing to include blood draw, and brief breathing test before and after an inhaled challenge with either filtered air (FA) or ozone (O3). Participants return the next day for a brief breathing test, a blood draw and a procedure called bronchoscopy performed under conscious sedation to evaluate the lung after the challenge.
Participants then return 18 - 20 days later to repeat the two-day series of testing to be challenged with the exposure not received on the first series, (FA or O3). Each visit will take about 3 - 3.5 hours. Follow-up phone calls from the study team will occur at 24 hours after each 2-day test series. Total study duration is about one to one-and a half months.
详细描述
In brief, at V1 subjects will be assessed for baseline spirometry and venous blood analysis prior to exposure. The venous blood will be used to obtain PMNs for apoptosis assays, and serum for CFH and sCD163 levels. Additionally, this will be used to measure cytokines and growth factors. At each visit, if the subject is female, there will be a urine pregnancy test performed. Following this initial assessment, subjects will be challenged with FA or O3 and then spirometry will be performed, and venous blood will be obtained immediately following the exposure (V2). The subjects will then return 20 hours ±4h later for follow up studies (V3). There will be spirometry, a venous blood draw and urine pregnancy testing (if female) followed by bronchoscopy. At bronchoscopy, vital signs will be determined, including O2 sat. Patient then undergo an 18-20 day washout period before they are brought back in for V4 for the alternate challenge. This will follow the same protocol as outline above in the initial exposure and use the same series of analysis as the first set of visits. Therefore, we will fully characterize the biological response to ozone and filtered air in these same subjects.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Other
- 盲法
- Single (Participant)
入排标准
- 年龄范围
- 18 Years 至 35 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- 未提供
排除标准
- 未提供
研究组 & 干预措施
Ozone (O3)
The O3 level during the exposures will be 200 ppb, which has previously been used in human exposure studies without short or long term, untoward side effects (and comparable to peak levels attained during the summer in the Raleigh-Durham area of North Carolina) (REF - Bromberg review).
干预措施: Ozone (Drug)
Filtered Air (FA)
Control will be treadmill walk with filtered room air in chamber.
干预措施: Filtered Air (Other)
结局指标
主要结局
Change in ozone induced phagocytosis of lung macrophages (ability to clear debris or bacteria)
时间窗: Baseline, 21 days
Bronchoalveolar macrophages are incubated with pHrodo™ dye-labeled particles. Macrophage phagocytosis will be defined by determining the number of macrophages that contain fluorescent particles versus the total macrophages Cell free hemoglobin and soluble CD163 - both are measured by commercial ELISA kit
change in ozone induced efferocytosis of lung macrophages (ability to clear dead or dying cells)
时间窗: Baseline, 21 days
Efferocytosis is defined by determining the number of apoptotic PMNs phagocytized by alveolar macrophages (BAL cytospins) versus the total number of macrophages ('efferocytic index')
次要结局
- Change in ozone induced increase in cell free hemoglobin in bronchoalveolar lavage fluid and serum(Baseline, 21 days)
- Change in ozone induced increase in soluble CD163 in bronchoalveolar lavage fluid and serum(Baseline, 21 days)
研究者
Robert Tighe, MD
Associate Professor of Medicine
Duke University