Recruiting

Phase 1

Observational StudyMacrophage Regulation of Ozone-Induced Lung Inflammation

Sponsor:

Robert Tighe, MD

Code:

NCT05773001

Conditions

Respiratory Viral Infection

Eligibility Criteria

Sex: All

Age: 18 - 55

Healthy Volunteers: Accepted

Interventions

Ozone

Study Details

Brief summary:

The purpose of this research study to understand how prior respiratory infections affect the susceptibility to lung inflammation following environmental exposures.

Conditions

Respiratory Viral Infection

Study ID

NCT05773001

Start date

May 18, 2023

Status verified date

May, 2026

Completion date

May, 2028

Anticipated

Primary completion date

May, 2028

Anticipated

Eligibility Criteria

Sex: All

Age: 18 - 55

Healthy Volunteers: Accepted

Inclusion Criteria:

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 Criteria:

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.

Study Design

Enrollment

100 participants

Anticipated

Allocation

Non randomized

Intervention Model

Crossover

Primary purpose

Other

Interventions and Outcome Measures

Arms

other: Cohort 1

no history of respiratory viral infection

other: Cohort 2

Documented mild respiratory viral infection

other: Cohort 3

Respiratory viral pneumonia

Interventions

Ozone

Subjects will perform alternating 15 minutes rest with 15 minutes treadmill walk exercise periods for 135 minutes in while breathing Ozone (O3).

Primary outcome measure

Change in the abundance of monocyte-derived alveolar macrophages [ Time Frame: Baseline, Day 18-20 ]

Central Contacts and Locations

Central contacts

Claudia Salazar

9196602026 claudia.salazar@duke.edu

Locations

Duke University Medical Center

Recruiting

Durham, North Carolina, United States, 27710

Contacts

Claudia Salazar, BS

919-660-2026 claudia.salazar@duke.edu

Principal Investigator:

Robert Tigher, MD

More Information

Sponsor

Robert Tighe, MD

Last update posted

May 15, 2026

Last verified

May, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Robert Tighe, MD on 2026-05-15.