NCT02327897 · National Institute of Environmental Health Sciences (NIEHS)
NHALES (Natural History of Asthma With Longitudinal Environmental Sampling)
What this study is about
Background: \- Asthma is a serious clinical and public health problem. Researchers want to collect data to better understand how bacteria and other things in the environment can affect people's asthma. Eligibility: \- Nonsmoking adults age 18 - 60 who have moderate to severe asthma. Design: * Participants will complete a medical history form before the first visit.
View original scientific description
Background: \- Asthma is a serious clinical and public health problem. Researchers want to collect data to better understand how bacteria and other things in the environment can affect people's asthma. Eligibility: \- Nonsmoking adults age 18 - 60 who have moderate to severe asthma. Design: * Participants will complete a medical history form before the first visit. * Study visits will include collecting medical history, and conducting physical exam, lung and smoking tests. Participants will give blood, urine, stool, dust, saliva, and sputum samples. * Participants will take tests that measure their breathing abilities. They will give saliva samples for DNA study. They will get kits to collect stool and dust samples at home. They will fill out surveys. * Participants will have visits every 6 months for 5 years. They can schedule sick visits, if needed, at no cost to the participant. For all visits, they will have asthma check-ups and get treatment, at no cost to the participant. * Some participants may take part in a sub-study that includes one 4-hour visit. They will have medical history, physical exam, and lung tests. They will have urine tests to check for pregnancy and tobacco exposure. Then they will have bronchoscopy. For this, an intravenous line will be placed in an arm vein. The nose and throat will be numbed. A flexible fiber-optic tube will be inserted into their airways through the nose. Their airways will be examined and areas of their lung will be washed. A small sample of cells will be taken.
Primary outcome measures
The overall goal is to study the natural history of atopic asthma, focusing on moderate to severe asthma. The primary objective is to collect prospective data and samples for future use to better understand the interaction between environmental ...
Time frame: End of Study
Results will be evaluated in the context of the environmental exposures, clinical outcomes (symptoms, exacerbations, and quality of life), and response to therapy.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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
- Research Triangle Park, North Carolina
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 16, 2026 · Source of record for eligibility and locations