An observational study in Leukocyte Disorders, Respiratory Tract Diseases and Bronchoscopy, sponsored by National Heart, Lung, and Blood Institute (NHLBI). Recruiting at 1 site in United States. Open to participants aged 5 Years to 100 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-11-09.
Sponsored by National Heart, Lung, and Blood Institute (NHLBI) · Observational
This study will collect fluid and tissue specimens from the lungs and nose of healthy people and people with a history of lung infections. The specimens will be examined for differences between the two groups that may be associated with susceptibility to certain infections.
Healthy normal volunteers and people with a history of lung infections between 18 and 75 years of age who are followed at NIH may be eligible for this study.
Participants undergo the following procedures:
Medical history and physical examination.
Blood and urine tests.
Electrocardiogram (ECG) and chest x-ray.
Treadmill exercise stress test (for people over 45 years old with a history of chest pain or ECG abnormalities).
Bronchoscopy: The subject s nose and throat are numbed with lidocaine and a sedative is given for comfort. A thin flexible tube called a bronchoscope is advanced through the nose or mouth into the lung airways to examine the airways carefully.
Fluid collection during the bronchoscopy using one of the following methods:
This research protocol involves one or more of the following procedures in healthy volunteers and patients with known or suspected predisposition to respiratory infection who are enrolled in National Institutes of Health (NIH) protocols: 1) Adults only: bronchoscopy with sampling of bronchoalveolar lavage fluid and epithelial cells in healthy adult volunteers and patients; 2) Adults and Children: sputum induction for collection of sputum specimens; 3) Adults and Children: nasal mucosal biopsies and brushings for sampling of epithelial cells; 4) Adults and Children: measurement of nasal nitric oxide production; 5) Adults and children: collection of exhaled breath condensate; 6) Adults and children: measurement of nasal potential difference; 7) Adults and children: exhaled aerosol mask sample collection; Adults and children: 8) cough aerosol collection. The cellular and acellular samples will be separated, and stored or transferred to the appropriate laboratories investigating these diseases.
Alveolar macrophages are the predominant (>95%) cell type present in the lavage of normal subjects. Alveolar macrophages play a central role in the initiation and propagation of lung inflammation by releasing cytokines (i.e., interleukin-1, tumor necrosis factor) and chemokines (i.e., interleukin-8, monocyte chemotactic protein, macrophage inflammatory protein) that activate other resident cells and recruit inflammatory cells to a local nidus of inflammation. Airway epithelial cells are known to release a variety of mediators as well. Thus, the interaction of cells with mediators generated by alveolar cells and bronchial epithelial cells during acute inflammation is a key element in the initiation of pulmonary inflammatory responses.
Bronchoalveolar lavage (BAL), bronchial brushings, and mucosal biopsies are standard diagnostic techniques done through the bronchoscope to obtain samples of alveolar and bronchial specimens for diagnosis of infection, malignancy, or non-infectious inflammation. Nasal mucosal scrape biopsy is a minimally invasive method of obtaining airway epithelial cells to diagnose disorders of airway clearance associated with abnormal cilia (hair-like structures on airway lining cells). Sputum induction is a routinely performed procedure to facilitate the collection of respiratory secretions (mucus) through stimulation of cough with inhalation of an aerosolized concentrated salt-water solution. Exhaled breath condensate is simply collected by breathing normally through a plastic tube inserted into a chilled cylinder. Nasal potential difference is performed by placing a small needle under the skin of the forearm that is connected to a salt solution bridge and resting a small catheter on the surface of the nose through which various salt solutions are dripped.
The objective of this protocol is to analyze bronchoalveolar lavage fluid, airway epithelial cells, sputum, and exhaled breath specimens and bedside physiologic measurements from healthy volunteers and from patients who acquire respiratory infections to look for differences in immune function and to discover new pathways of infectious disease susceptibility. We hypothesize that studying cellular responses to infection and inflammatory markers released from these cells will further our understanding of human susceptibility to respiratory tract infections.
Five hundred fifty subjects (250 healthy volunteers and 300 patients) will undergo one or more of the following: 1) bronchoscopy with bronchoalveolar lavage, bronchial brushings, endobronchial biopsies; 2) nasal mucosal scrape and/or brush biopsies; 3) sputum induction 4) exhaled breath condensate to obtain specimens for in vitro investigations and comparisons of both the cellular and acellular components. Bedside measurements 5) nasal nitric oxide production and 6) nasal potential difference 7) exhaled aerosol mask sample collection 8) cough aerosol collection 9) Exhaled particle collection; 10) Lung Clearance Index (LCI) may be done to assess airway infection and epithelial cell functions in real-time.
410 studies on the registry are indexed under Respiratory Tract Diseases; 59 are open to participants now.
This study's planned enrollment of 550 is above the median of 226 across 79 observational studies indexed under Respiratory Tract Diseases.
Browse Respiratory Tract Diseases studies →National Heart, Lung, and Blood Institute (NHLBI) is the lead sponsor of 1,143 studies on the registry; 71 are open to participants now.
Of its 58 completed or terminated interventional studies of FDA-regulated products, 51 (88%) have results posted.
Counted across the registry records on this site, refreshed daily.
Healthy volunteers and NIH patients with known or suspected susceptibility to infection.@@@@@@
HEALTHY VOLUNTEER INCLUSION CRITERIA FOR BRONCHOSCOPY AND BRONCHOSCOPIC PROCEDURES:
HEALTHY VOLUNTEER EXCLUSION CRITERIA FOR BRONCHOSCOPY AND BRONCHOSCOPIC PROCEDURES:
PATIENT INCLUSION CRITERIA FOR BRONCHOSCOPY AND BRONCHOSCOPIC PROCEDURES
PATIENT EXCLUSION CRITERIA FOR BRONCHOSCOPY AND BRONCHOSCOPIC PROCEDURES
History of recent/acute clinically significant pulmonary compromise. This will be defined by the following criteria:
HEALTHY VOLUNTEER INCLUSION CRITERIA FOR NASAL MUCOSAL , NASAL NITRIC OXIDE MEASUREMENT, AND NASAL POTENTIAL DIFFERENCE MEASUREMENT:
HEALTHY VOLUNTEER EXCLUSION CRITERIA FOR NASAL MUCOSAL BIOPSY, NASAL NITRIC OXIDE MEASUREMENT, AND NASAL POTENTIAL DIFFERENCE MEASUREMENT:
PATIENT INCLUSION CRITERIA FOR NASAL MUCOSAL BIOPSY, NASAL NITRIC OXIDE MEASUREMENT, NASAL POTENTIAL DIFFERENCE MEASUREMENT, SPUTUM INDUCTION, COUGH AEROSOL SAMPLING, EXHALED AEROSOL MASK SAMPLE COLLECTION, COLLECTION OF EXHALED PARTICLES, AND LCI:
PATIENT EXCLUSION CRITERIA FOR NASAL MUCOSAL BIOPSY, NASAL NITRIC OXIDE MEASUREMENT, NASAL POTENTIAL DIFFERENCE MEASUREMENT, SPUTUM INDUCTION, COUGH AEROSOL SAMPLING, EXHALED AEROSOL MASK SAMPLE COLLECTION, COLLECTION OF EXHALED PARTICLES, AND LCI:
HEALTHY VOLUNTEER INCLUSION CRITERIA FOR SPUTUM INDUCTION, EXHALED BREATH CONDENSATE COLLECTION COUGH AEROSOL SAMPLING, EXHALED AEROSOL MASK SAMPLE COLLECTION, COLLECTION OF EXHALED PARTICLES, AND LCI:
HEALTHY VOLUNTEER EXCLUSION CRITERIA FOR SPUTUM INDUCTION, EXHALED BREATH CONDENSATE COLLECTION, COUGH AEROSOL SAMPLING, EXHALED AEROSOL MASK SAMPLE COLLECTION, COLLECTION OF EXHALED PARTICLES, AND LCI:
PATIENT INCLUSION CRITERIA FOR SPUTUM INDUCTION, EXHALED BREATH CONDENSATE COLLECTION, COUGH AEROSOL SAMPLING, EXHALED AEROSOL MASK SAMPLE COLLECTION, COLLECTION OF EXHALED PARTICLES, AND LCI:
PATIENT EXCLUSION CRITERIA FOR SPUTUM INDUCTION, EXHALED BREATH CONDENSATE, COUGH AEROSOL SAMPLING, EXHALED AEROSOL MASK SAMPLE COLLECTION, COLLECTION OF EXHALED PARTICLES, AND LCI:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Healthy Volunteers
NIH patients with known or suspected susceptibility to infection.
obtain bronchoalveolar lavage fluid, sputum, and/or airway epithelial cells from healthy volunteers and from patients who acquire respiratory infections, to look for differences in immune function between these groups, and to discover new pat...
to obtain respiratory tract cells fluids, and bedside physiologic measurements from normal and diseased subjects to support current bench research studies or to be stored for future studies.
Time frame: 10 years
Plan to share: Undecided
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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