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Understanding Lung Inflammation from Ozone Exposure

This study aims to understand how past respiratory viral infections affect your lungs' reaction to environmental exposures. Researchers will study individuals aged 18-55 who have different histories of respiratory viral infections. Participants will breathe Ozone (O3) during exercise to see how it affects their lungs. The main goal is to measure changes in specific immune cells called monocyte-derived alveolar macrophages (a type of white blood cell in your lungs) after exposure. The study is currently recruiting participants.

Study design
This is an interventional study planning to enroll 100 participants. It involves different groups based on your history of respiratory viral infection.
What's involved
You will have a 1-day screening, followed by two separate 2-day testing series, each about 18-20 days apart. Each visit will take 3-3.5 hours, and you'll have follow-up phone calls after each 2-day series. The total study duration is about one to one-and-a-half months.
Compensation
Not stated in the trial record.
Follow-up
You will have follow-up phone calls 24 hours after each 2-day test series. The primary endpoint, measuring changes in immune cells, is taken at Baseline and Day 18-20.

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NCT05773001

Macrophage Regulation of Ozone-Induced Lung Inflammation

Recruiting
PHASE1Ages 18–55Interventional
Robert Tighe, MD
~100 participants
Updated 2026-05-15 on ClinicalTrials.gov
What's tested:Ozone

At a glance

Recruiting sites
1 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Change in the abundance of monocyte-derived alveolar macrophages
Measured over Baseline, Day 18-20

Conditions

Respiratory Viral Infection

Explore related trials

Viral respiratory infection

Where it's being run

1 sites across 1 states
North Carolina1

Study leadership

  • Robert Tighe, MD · PRINCIPAL_INVESTIGATOR · Duke University

Who to contact

Claudia Salazar
[email protected]
9196602026
Email the study team

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Do you actually qualify for this trial?

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Eligibility criteria

Inclusion

Individuals between 18-55 yrs. of age (No subject will be excluded from the study on the basis of gender or ethnicity)
Individuals with knowledge of prior respiratory viral infection history allowing them to be segregated into one of three cohorts
Cohort 1 - No history of respiratory viral infection (defined as no symptoms consistent with respiratory viral infection nor history of a positive respiratory viral test)
Cohort 2 - Documented mild respiratory viral infection (a positive test, either PCR- or antigen-based) but with mild to no symptoms and no evidence of a lower respiratory tract infection (including no hospitalization, and no oxygen use)
Cohort 3 - History of respiratory viral infection and symptoms/imaging consistent with a lower respiratory tract infection who have recovered, are \>6 months out from their infection, and have normal lung function (spirometry with FVC, FEV1 and FEV1/FVC)
There will be no maximal period from respiratory viral infection for inclusion in the study, the minimal period will be \>6 months out from infection

Exclusion

Individuals with prior respiratory viral pneumonia who have ongoing respiratory symptoms, are still using supplemental oxygen, or have abnormal lung function
Current smokers of tobacco products including e-cigarettes or those with previous smoking history within the prior 5 years
Pregnant women and women who are presently lactating.
Subjects that have received antibiotic administration or an upper respiratory infection within the previous 4 weeks
College and graduate students or employees who are under direct supervision by any of the investigators in this protocol
Alcohol or illicit substance abuse
Chronic cardio/pulmonary respiratory disorders or other medical conditions as determined by the investigator
Increased airway hyperresponsiveness at baseline as measured by a positive methacholine challenge response (methacholine PC20 FEV1 \< 4 mg/ml)
Subjects will be requested to refrain from antihistamines, nonsteroidal anti-inflammatory agents, antioxidants (e.g. beta-carotene, selenium, and lutein) and supplemental vitamins (e.g. C and E), for 1 week prior to, and during testing.

What this trial measures

  • Change in the abundance of monocyte-derived alveolar macrophagesBaseline, Day 18-20

    Change in the abundance of monocyte-derived alveolar macrophages and association to measures of O3-induced inflammation (BAL cell neutrophils, albumin and cytokine production)