Understanding how environmental factors affect asthma

Natural History of Asthma With Longitudinal Environmental Sampling

This study looks at how different environmental factors affect asthma in adults with moderate to severe asthma to see if they can help explain why symptoms get worse.

Quick facts

• Study type: Observational
• Enrollment: 400 (estimated)
• Ages: 18 Years to 60 Years
• Sex: All
• Sponsor: National Institutes of Health Clinical Center (CC) (nih)
• Locations: 1 site (Research Triangle Park, North Carolina)
• Trial ID: NCT02327897 on ClinicalTrials.gov

What this trial studies

This observational study aims to collect data on the natural history of asthma by examining the relationship between environmental exposures and disease progression in adults with moderate to severe atopic asthma. Participants will undergo a series of assessments, including medical history, physical exams, and various sample collections (blood, urine, saliva, stool, and dust) over a five-year period. The study will also utilize surveys to gather quality of life information and explore the microbiological and genetic influences on asthma symptoms and control. By analyzing these samples and data, researchers hope to identify potential mechanisms linking environmental factors to asthma exacerbations.

Who should consider this trial

Good fit: Ideal candidates for this study are nonsmoking adults aged 18 to 60 with moderate to severe atopic asthma.

Not a fit: Patients with chronic obstructive pulmonary disease or cystic fibrosis may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved understanding and management of asthma by identifying environmental triggers and their impact on disease progression.

How similar studies have performed: Other studies have shown success in exploring the relationship between environmental factors and asthma, making this approach both relevant and promising.

Eligibility criteria

* Inclusion Criteria

Participants must meet all of the following criteria for enrollment:

* Male or female, 18 to 60 years of age
* Must have clinical evidence of moderate-severe atopic asthma:

  * self-reported symptoms suggestive of asthma (such as wheezing, chest tightness, shortness of breath, cough nocturnal symptoms)

within the past year, and

--\*a positive methacholine test confirming diagnosis \[provocative concentration causing a 20% fall in forced expiratory volume in 1 second (PC20 FEV1) \<16 mg/mL for participants on inhaled corticosteroids and \<8 mg/mL for participants not on inhaled corticosteroids\] or postbronchodilator FEV1 with at least 12% or 200 mL increase in FEV1 or forced volume vital capacity (FVC) on bronchodilator challenge, and

--no other diagnosis that could explain symptoms.

If there is documentation of a recent methacholine challenge, those results may be used in lieu of conducting a secondary methacholine challenge.

* Permanently resides within 50 miles of the CRU.
* Able to present a valid government issued form of identification for entry to the NIEHS campus
* Able to receive asthma treatment medication(s) via mail
* Willingness to comply with instructions regarding medication regimen, diet, and life style as directed by the investigator that are required per protocol
* Access to a vacuum cleaner with a detachable hose component

  * If a woman is found to be pregnant or breastfeeding at the screening or baseline visit, they may continue their participation in the study but will be excluded from participation in the methacholine challenge and bronchoscopy procedures in this study while pregnant.

Bronchoscopy Visit Inclusion Criterion

In addition to the above inclusion criteria, participants must be able to fast for 6 hours (no food or drink, except a small amount of water if needed to take approved medications) prior to the bronchoscopy visit in order to be eligible for enrollment in the bronchoscopy visit.

Exclusion Criteria

Participants meeting any of the following criteria at screening will not be eligible for enrollment or to continue with study visits:

* Current smoker, significant second-hand smoke exposure (defined by urine cotinine \>200 ng/mL at screening), or a history of smoking greater than 5 pack years. Smoking encompasses all inhaled products, including e-cigarettes.
* piCO Smokealyzer value of \>11ppm
* History of the following comorbidities: chronic obstructive pulmonary disease, cystic fibrosis (CF), emphysema, non-CF bronchiectasis, pulmonary fibrosis, sarcoidosis, unstable angina, pulmonary hypertension
* Allergy or history of adverse reactions to methacholine
* Any condition that, in the investigator's opinion, places the participant at undue risk for complications associated with required study procedures
* Comorbid diseases that affect global health or survival- such as DVT, pulmonary embolism, class III - IV congestive heart failure, or a malignancy under treatment

Bronchoscopy Visit Exclusion Criteria

In addition to the above exclusion criteria, participants meeting any of the following criteria will not be eligible for enrollment into the bronchoscopy visit:

* Pregnancy, as indicated by urine pregnancy test, if of childbearing age and/or ability contraindication
* Any condition that, in the investigator's opinion, places the participant at undue risk for complications associated with bronchoscopy
* Bleeding disorders
* Facial deformity, major facial surgery
* Asthma exacerbation or respiratory infection less than or equal to 4 weeks prior to study visit
* Severe persistent asthma, defined as by ATS-ERS criteria.
* Allergy or history of adverse reactions to lidocaine
* Temperature \>37.6 (Infinite)C; blood pressure \<90/50 mm Hg or \>160/100 mm Hg; pulse rate \<50 or \>100 beats/minute
* Body weight \<50 kg (\<110 lbs)
* The following abnormal lab values (values obtained during clinical assessment):

  * Platelet count \<100,000 per microliters
  * White blood cells count \<3000 per microliters
  * Absolute neutrophil count \<1000 per microliters
  * Hematocrit \<35% for both female and male
  * Prothrombin time (PT) / abnormal international normalized ratio (INR) and partial prothromboplastin time (PTT) based on reference laboratory established reference ranges
  * Serum creatinine \>1.4 mg/dL

If a participant is recruited for the Bronchoscopy Visit but does not have current lab values (within 4 weeks), the participant may be asked to return to the CRU for an additional blood draw in order to run the requisite clinical assessments for safety purposes. The participant will be compensated for the additional visit. This is anticipated to be a rare occurrence, as the study team will make all efforts to schedule and complete the bronchoscopy procedure while the lab results are current.

Participants with active bronchospasm on the day of the bronchoscopy will not undergo bronchoscopy.

Where this trial is running

Research Triangle Park, North Carolina

• NIEHS Clinical Research Unit (CRU) — Research Triangle Park, North Carolina, United States (RECRUITING)

Study contacts

• Principal investigator: Stavros Garantziotis, M.D. — National Institute of Environmental Health Sciences (NIEHS)
• Study coordinator: NIEHS Join A Study Recruitment Group

Conditions: Asthma, Atopic Asthma, Exposures, Disease Progression, Natural History