Can your genes predict wood smoke harm?

NCT ID NCT02767973

What the study statuses mean

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Recruitment status, easiest to join first

Recruiting now
This trial is taking on new participants right now.
Not yet recruiting
Registered, but not yet taking participants.
By invitation only
Not open to general applications. Only people the study team invites can take part.
Paused This study
Paused for now. It may or may not start again.
Ongoing
Running, but no longer taking on new participants.
Completed
The trial has finished. Results may not be published yet.
Stopped early
Stopped early, before it reached the end. That can be for many reasons, including safety.
Cancelled
Cancelled before anyone took part.

Expanded access (not trials)

Expanded access
Not a trial. This treatment can be requested outside a study, case by case, for people who qualify.
Expanded access (paused)
Not a trial. The treatment can normally be requested outside a study, but is unavailable right now.
Expanded access (ended)
Not a trial. The treatment could once be requested outside a study, but no longer can.
Approved
The treatment has been approved, so it is available normally rather than through this programme.

When the status isn't known

Details not published
The full record has not been published yet, so there is little to show here.
Status unknown
This status has not been confirmed recently, so it may be out of date.

First seen Aug 20, 2026 · Last updated Aug 21, 2026 · Updated 1 time

Summary

This study explores why some people develop airway inflammation after breathing wood smoke while others do not. Researchers will expose healthy adults and those with mild allergic asthma to controlled wood smoke particles and measure immune cell changes in the lungs. They will also check whether a genetic variant called GSTM1 influences this response. The goal is to better understand individual susceptibility to wood smoke-related inflammation.

What this could mean

Our plain-language read of the trial. This is informational only, not medical advice or a prediction.

Active substance
Wood smoke particles (WSP) inhaled during controlled exposure
What this could lead to
If successful, this could identify genetic factors that make some people more sensitive to wood smoke, potentially guiding personalized advice or protections.
What could go wrong
This is an early, small study focused on understanding biology, not treating disease. Results may not apply to real-world exposure or lead directly to interventions.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Study facts

What this study's own registry entry says, in plain language.

Phase

Not a phased trial

Phase numbers describe drug development. The registry uses this when they do not apply, as it does for trials of devices, procedures or behaviour changes, and for observational studies.

Participants

About 160 people

The number the study aims to enrol. It can still change while the study runs.

Started

Jun 2016

Expected to finish

May 2027

An estimate. End dates often move.

Lead sponsor

Other sponsor

The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Ages

18 to 45 years

Sex

Anyone

Healthy volunteers

Accepted

You do not need to have the condition being studied to take part.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria 1. Age 18-45 of both genders 2. Negative pregnancy test for females who are not s/p hysterectomy with oopherectomy 3. Calculated 10 year risk of CVD by the Framingham risk score of \<5% 4. Proof of Covid vaccination Specific for Healthy Volunteers 4\. No history of episodic wheezing, chest tightness or shortness of breath consistent with asthma, or physician diagnoses asthma. 5\. FEV1 of at least 80% of predicted and FEV1/FVC ratio of at least .70 Specific for Allergic Asthmatic Volunteers 6\. History of episodic wheezing, chest tightness, or shortness of breath consistent with asthma, or physician diagnosed asthma. 7\. A POST-bronchodilator increase in FEV1 of at least 12%, OR a clinical history of asthma after the age of 6. 8\. FEV1 of at least 75% of predicted without use of short acting bronchodilating medications for 12 hours, consistent with lung function of persons with no more than mild episodic or mild persistent asthma. 9\. Mild persistent asthmatics must be well controlled (in accordance with NHLBI guidelines) and willing to discontinue Singulair, inhaled corticosteroids or cromolyn for a period of 2 weeks prior to study visits (except for use of cromolyn exclusively prior to exercise) 10\. Allergic sensitization to at least one of the following allergen preparations: (House Dust Mite f, House dust mite p, Cockroach, Tree mix, Grass Mix, Weed Mix, Mold Mix 1, Mold Mix 2, Rat, Mouse, Guinea Pig, Rabbit, Cat or Dog) confirmed by positive immediate skin test response; or a clinical history consistent with seasonal or perennial allergy symptoms. 11\. Subjects must be willing to avoid caffeine for 12 hours prior to all visits. Allergy skin testing are performed as part of IRB98-0799, which a subject must complete in order to be considered for this protocol. Exclusion Criteria Patients who meet any of these criteria are not eligible for enrollment as study participants: 1. Clinical contraindications: 1. Any chronic medical condition considered by the PI as a contraindication to the exposure study including significant cardiovascular disease, diabetes, chronic renal disease, chronic thyroid disease, history of chronic infections/immunodeficiency, history of tuberculosis. 2. Viral upper respiratory tract infection within 4 weeks of challenge. 3. Any acute infection requiring antibiotics within 4 weeks of exposure or fever of unknown origin within 4 weeks of challenge. 4. Abnormal physical findings at the baseline visit, including but not limited to abnormalities on auscultation, temperature of 37.8° C, Systolic BP \> 150mm Hg or \< 85 mm Hg; or Diastolic BP \> 90 mm Hg or \< 50 mm Hg, or pulse oximetry saturation reading less than 94%. 5. Unwillingness to use reliable contraception if sexually active (IUD, birth control pills/patch, condoms). 6. Use of immunosuppressive or anticoagulant medications including routine use of NSAIDS. Oral contraceptives are acceptable, as are Antidepressants and other medications may be permitted if, in the opinion of the investigator, the medication will not interfere with the study procedures or compromise safety and if the dosage has been stable for 1 month 7. Orthopedic in juries or impediments that would preclude bicycle or treadmill exercise. 8. Mental illness or history of drug or alcohol abuse that, in the opinion of the investigator, would interfere with the participant's ability to comply with study requirements. 9. Medications which may impact the results of the WSP exposure, interfere with any other medications potentially used in the study (to include steroids, beta antagonists, non-steroidal anti-inflammatory agents). 10. Inability to avoid NSAIDS, Multivitamins, Vitamin C or E or herbal medications in the 4 days prior to the screening visit the exposure session. 11. Symptomatic allergic rhinitis or current active allergies. 12. Cigarette smoking \> 1 pack per month 13. Current symptoms of Covid infection 14. Positive Covid test in the past 90 days Specific for Healthy Volunteers 15. Physician diagnosis of asthma. Specific for Asthmatic Volunteers 16. Physician directed emergency treatment for an asthma exacerbation within the preceding 3 months 17. Moderate or Severe asthma 18. Exacerbation of asthma more than 2x/week which would be characteristic of a person of moderate or severe persistent asthma as outlined in the current NHLBI guidelines for diagnosis and management of asthma. 19. Daily requirement for albuterol due to asthma symptoms (cough, wheeze, chest tightness) which would be characteristic of a person of moderate or severe persistent asthma as outlined in the current NHLBI guidelines for diagnosis and management of asthma. (Not to include prophylactic use of albuterol prior to exercise). 20. Nighttime symptoms of cough or wheeze greater than 1x/week at baseline (not during a clearly recognized viral induced asthma exacerbation) which would be characteristic of a person of moderate or severe persistent asthma as outlined in the current NHLBI guidelines for diagnosis and management of asthma 21. History of intubation for asthma 22. Use of systemic steroid therapy within the preceding 3 months for an asthma exacerbation. All use of systemic steroids in the last year will be reviewed by a study physician. 23. Use of inhaled steroids, cromolyn or leukotriene inhibitors (Montelukast or Zafirlukast) except for use of cromolyn exclusively prior to exercise. 24. Use of daily theophylline within the past month

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Conditions

The condition(s) this trial relates to.

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

How to take part

Only the study team decides who joins. These are the ways to reach them.

  1. The places running it

    1 site. The list below names each one and where it is.

  2. The official record

    The full official record for this study. This one lists no contact details, but it is the first place any would appear.

    Open the record ↗

  3. A doctor treating you

    A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.

Contacts and locations

Locations

  • UNC Center For Environmental Medicine, Asthma and Lung Biology

    Chapel Hill, North Carolina, 27599, United States

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