Actively Recruiting
Macrophage Regulation of Ozone-Induced Lung Inflammation
Led by Robert Tighe, MD · Updated on 2026-05-15
100
Participants Needed
1
Research Sites
N/A
Total Duration
On this page
Sponsors
R
Robert Tighe, MD
Lead Sponsor
N
National Institutes of Health (NIH)
Collaborating Sponsor
AI-Summary
What this Trial Is About
This research investigates how past respiratory infections influence the risk of lung inflammation after exposure to environmental agents like ozone. The study focuses on adults aged 18 to 55 and aims to understand changes in lung immune cells, specifically macrophages, following these exposures. Participants are grouped based on their history of respiratory viral infections, including no infection, mild infection, or viral pneumonia recovery. Participants undergo an initial 1-day screening involving blood tests and breathing assessments. They then return for two separate 2-day testing series spaced 18 to 20 days apart. During these visits, participants experience inhaled challenges with either filtered air or ozone while performing alternating rest and treadmill walking for 135 minutes. After each challenge, lung evaluation includes blood draws, breathing tests, and bronchoscopy. Follow-up phone calls occur 24 hours after each test series. The study measures changes in specific lung macrophage populations at baseline and after the exposures. Participants are monitored for lung function and immune responses over about one to one-and-a-half months. The study includes safety monitoring and excludes individuals with ongoing lung issues or recent infections. The goal is to better understand lung inflammation related to environmental exposures and prior infections.
CONDITIONS
Brief Title
Macrophage Regulation of Ozone-Induced Lung Inflammation
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Individuals between 18-55 years of age
- Individuals with known prior respiratory viral infection history allowing classification into one of three groups:
- No history of respiratory viral infection
- Documented mild respiratory viral infection with mild or no symptoms and no lower respiratory tract infection
- History of respiratory viral pneumonia with recovery, at least 6 months post-infection, and normal lung function
You will not qualify if you...
- Individuals with ongoing respiratory symptoms, supplemental oxygen use, or abnormal lung function after respiratory viral pneumonia
- Current smokers or those who smoked tobacco or e-cigarettes within the past 5 years
- Pregnant or lactating women
- Recent antibiotic use or upper respiratory infection within 4 weeks
- College or graduate students/employees under direct supervision of study investigators
- History of alcohol or illicit substance abuse
- Chronic cardiopulmonary or other medical conditions as determined by investigators
- Increased airway hyperresponsiveness at baseline (positive methacholine challenge with PC20 FEV1 < 4 mg/ml)
- Use of antihistamines, NSAIDs, antioxidants, or supplemental vitamins within 1 week prior to and during testing period
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 1 day
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - Approximately 1 to 1.5 months total with two 2-day test series separated by 18 to 20 days
Participants undergo two series of testing involving blood draws, breathing tests, and exposure challenges with filtered air or ozone, including a bronchoscopy procedure to evaluate the lung after exposure.
Two 2-day series of testing visits, each visit lasting about 3 to 3.5 hours, plus follow-up phone calls 24 hours after each series
Trial Site Locations
Total: 1 location
1
Duke University Medical Center
Durham, North Carolina, United States, 27710
Actively Recruiting
Research Team
C
Claudia Salazar
How is the study designed?
Study Type
INTERVENTIONAL
Masking
SINGLE
Allocation
NON_RANDOMIZED
Model
CROSSOVER
Primary Purpose
OTHER
Number of Arms
3
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