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Characterization of Tissue-Specific Immune Responses to Bronchoscopic Instillation of Mycobacterial Antigens Into the Human Lung

Characterization of Tissue-Specific Immune Responses to Bronchoscopic Instillation of Mycobacterial Antigens Into the Human Lung

Status
Completed
Phases
Early Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05027958
Enrollment
17
Registered
2021-08-31
Start date
2022-05-03
Completion date
2024-12-08
Last updated
2026-05-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy, Latent Tuberculosis Infection (LTBI)

Keywords

Tuberculin Purified Protein Derivative, PPD, antigen-specific immune cells in airways

Brief summary

Background: Tuberculosis (TB) is a lung disease. It is caused by inhaling a type of airborne bacterium. Tuberculin Purified Protein Derivative (PPD) is used to test for TB exposure. It is usually injected under a person s skin. In this study, it will be applied in the lung. Objective: To learn how the cells within the lung react (immune response) when exposed to PPD. Eligibility: Adults ages 18-64 who (1) have been exposed to TB but do not have active disease or symptoms or (2) have never been exposed to TB. Design: Participants will be screened with a medical history, physical exam, and blood tests. They will have a TB skin test. They will also have an electrocardiogram to examine heart rhythm. For this, sticky patches will be placed on their chest. Some screening tests will be repeated at study visits. Participants will have 3 FDG PET-CT scans. They will lie in a machine that creates pictures of the inside of their body. They will get a radioactive substance injected into their arm called 18FDG. It helps make the pictures. Participants will have 3 bronchoscopies. Their mouth and nasal airways will be numbed. They will get drugs to relax. A tube will be inserted through their nose or mouth into a lung. Fluid will be delivered into the lung and suctioned back out to collect cells. They will get PPD during the first bronchoscopy. Participation will last for about 30 days. Participants will visit the clinic up to 8 times. They will go home after each procedure. No hospital stays are needed....

Detailed description

Study Description: We propose a pilot study in which we employ directed bronchoscopic instillation of Mycobacterium tuberculosis (Mtb)-Tuberculin Purified Protein Derivative (PPD) to evaluate local airway immune response in adults with or without latent tuberculosis infection (LTBI). Primary Objective: The primary objective of this study is to understand the pulmonary immune response to mycobacterial antigens by determining the persistence of antigen-specific immune cells in the airways versus circulation after local bronchoscopic instillation of Tuberculin Purified Protein Derivative (PPD) into the lungs of adults with or without LTBI. Secondary Objective: The secondary objective is to characterize the location and persistence of immune cell activity in the pulmonary parenchyma and thoracic lymph nodes with positron emission tomography combined with chest computed tomography (PET-CT) after bronchoscopic Tuberculin Purified Protein Derivative (PPD) instillation in adults with or without LTBI. Exploratory Objectives: (a) An exploratory objective will be to perform phenotypic and functional analysis of immune cell populations in the airways vs circulation following bronchoscopic instillation of Tuberculin Purified Protein Derivative (PPD) into the lungs of individuals with or without LTBI. (b) An additional exploratory objective will be to characterize the production of soluble mediators (including but not limited to: cytokines, lipid mediators, and defensins) in BAL fluid vs blood within the same context. Endpoints: Primary Endpoint: The primary endpoint will be the enumeration of Mtb antigen-specific CD4+ and CD8+ T cell populations in the airway and peripheral blood at early and late time points after bronchoscopic Tuberculin Purified Protein Derivative (PPD) instillation. Secondary Endpoint: The secondary endpoint will be the quantification of \[18F\]fluoro-D-glucose (FDG) uptake in adjacent pulmonary parenchyma and draining thoracic lymph nodes via PET-CT at early and late time points after PPD instillation. Exploratory Endpoints: (a) An exploratory endpoint will be the quantification of frequencies of cell surface molecules, intracellular cytokines and transcription factors among immune cell populations in the airways vs circulation following bronchoscopic instillation of Tuberculin Purified Protein Derivative (PPD) into the lungs of individuals with or without LTBI. (b) An exploratory endpoint will involve the identification and quantification of soluble mediators in the airway and peripheral blood after PPD instillation in the lungs within the same context.

Interventions

PPD administered through the airways to elicit the development of alveolar inflammation challenge dose of 0.5 TU

Sponsors

National Heart, Lung, and Blood Institute (NHLBI)
Lead SponsorNIH

Study design

Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Investigator)

Eligibility

Sex/Gender
ALL
Age
18 Years to 64 Years
Healthy volunteers
No

Inclusion criteria

* INCLUSION CRITERIA: Adults 18-64 years old will be recruited for the two groups (non-LTBI controls vs confirmed LTBI). The lower limit of this age range is based on the need for invasive bronchoscopic procedures and exposure to radiation, both of which carry more risk at younger ages. In addition, most adults present with post-primary or reactivation TB that most often occurs radiographically in the upper lobes of the lungs, often with cavitation. Conversely, children and rare adults with primary TB have non-cavitary disease in the lower lobes. The higher limit of this age range is based on the known property of immune senescence, i.e., the waning of the strength of immune responses with advancing age. In order to be eligible to participate in this study, an individual must meet all of the following criteria: * Ability of subject to understand and the willingness to sign a written informed consent document. * Stated willingness to comply with all study procedures and availability for the duration of the study * Male or female, aged 18 - 64 years of age * No significant active medical problems. This would include but not limited to any cardiac disorder (e.g. arrhythmia, valvular disease), pulmonary disease (e.g. asthma requiring chronic medications, chronic bronchitis, emphysema, obstructive sleep apnea), kidney disease (e.g. nephritis, nephrosis), rheumatologic disorder (e.g. inflammatory arthritis), endocrine disorder (e.g. diabetes, thyroid disease), liver disease (e.g. hepatitis), gastrointestinal disorder (e.g. inflammatory bowel disease) or infectious disease (e.g. active tuberculosis). * For females of reproductive potential: use of highly effective contraception for at least 1 month prior to screening and agreement to use such a method during study participation * For males of reproductive potential: use of condoms or other methods to ensure effective contraception with partner and agreement to use such a method during study participation

Exclusion criteria

An individual who meets any of the following criteria will be excluded from participation in this study: * Pregnancy as assessed by urinary or plasma HCG or breastfeeding * History of clinically significant respiratory dysfunction 3 months prior to participating * Evidence of new pulmonary infection * History of any chronic lung infections or chronic lung disease * History of pulmonary hypertension * Need for supplemental oxygen administration at rest * Current use or inability to suspend use of anticoagulant therapy including platelet inhibitors (e.g. clopidogrel) within 7 days of study bronchoscopy or systemic anticoagulants (e.g. warfarin, enoxaparin, or DOAC) within 14 days of study bronchoscopy * Any symptoms consistent with infection including fever, chills, night sweats, or unexplained weight loss * A history of a necrotic reaction to a tuberculin skin test, including during screening * A history of human immunodeficiency virus (HIV) infection * A history of coughing up blood in the last 3 months * Cigarette smoking, vaping or recreational drug use within the past 6 months (self-reported) * If there is any discrepancy in tuberculin skin test and Interferon Gamma Release Assay test results (i.e. PPD+ but IGRA- or PPD- but IGRA+) * Refusal or inability to undergo bronchoscopy, or a history of poor tolerance of a bronchoscopy * If undergoing PET-CT imaging during this study places a participant over his/her annual radiation dose limit. Radiation exposure within the previous 12 months of \>= 2.3 rem * BMI \> 40 * Diabetes * Known life-threatening allergic reaction to Tuberculin, Lidocaine, Midazolam, Fentanyl or medications of similar classes * Presence of any immunosuppressive diseases, including cancers with the exception of non-melanomatous skin cancer. * Use of any systemic immunosuppressive medications, including corticosteroids (e.g., prednisone) or biological agents in the last 6 months prior to enrollment * Any medical, psychiatric, social condition, occupational reason or other responsibility, in the judgement of the investigator, that is a contraindication to protocol participation or impairs a participant s ability to give informed consent * Positive for COVID-19. (with-in 6 months prior to enrollment self-reported and or via PCR)

Design outcomes

Primary

MeasureTime frameDescription
Median Difference in CD4 Cell Response to Intrabronchial Instillation of Tuberculin Purified Protein Derivative (PPD)Day 5 and Day 21Median difference in CD4 cell response to intrabronchial instillation of Tuberculin Purified Protein Derivative (PPD) using flow cytometry. The frequency of (Mycobacterium tuberculosis) Mtb-specific T cells was measured by intracellular cytokine staining for Interferon Gamma (IFNγ) and Tumor Necrosis Factor (TNF) after in vitro restimulation of Peripheral Blood Mononuclear Cells (PBMC) and Bronchoalveolar Lavage (BAL) cells with PPD or Mtb-derived peptide megapools.

Secondary

MeasureTime frameDescription
Median Difference in the Standard Uptake Value (SUV)Baseline (Up to -7 days prior to PPD instillation), Day 4 and Day 20Median difference in the Standard Uptake Value (SUV) in the pulmonary parenchyma and thoracic lymph nodes with positron emission tomography combined with chest computed tomography (PET-CT)

Countries

United States

Contacts

PRINCIPAL_INVESTIGATORKevin P Fennelly, M.D.

National Heart, Lung, and Blood Institute (NHLBI)

Participant flow

Participants by arm

ArmCount
Arm 1: Healthy Volunteer Participants With Confirmed Latent Tuberculosis Infection (LTBI)
Healthy volunteer participants with confirmed Latent Tuberculosis Infection (LTBI) (TST positive and IGRA positive) receiving instillation dose of purified protein derivative (PPD) 0.5 tuberculin units (10 uL Tubersol® in 10 mL normal saline) into the right upper lobe of lung. Tuberculin Purified Protein Derivative: PPD administered through the airways to elicit the development of alveolar inflammation challenge dose of 0.5 TU
7
Arm 2: Healthy Volunteer Participants With Confirmed Non-Latent Tuberculosis Infection (LTBI)
Healthy volunteer participants with confirmed non-Latent Tuberculosis Infection (LTBI) (TST negative and IGRA negative) receiving instillation dose of purified protein derivative (PPD) 0.5 tuberculin units (10 uL Tubersol® in 10 mL normal saline) into the right upper lobe of lung. Tuberculin Purified Protein Derivative: PPD administered through the airways to elicit the development of alveolar inflammation challenge dose of 0.5 TU
10
Total17

Baseline characteristics

CharacteristicArm 1: Healthy Volunteer Participants With Confirmed Latent Tuberculosis Infection (LTBI)Arm 2: Healthy Volunteer Participants With Confirmed Non-Latent Tuberculosis Infection (LTBI)Total
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
0 Participants0 Participants0 Participants
Age, Categorical
Between 18 and 65 years
7 Participants10 Participants17 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
1 Participants0 Participants1 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
6 Participants10 Participants16 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
0 Participants2 Participants2 Participants
Race (NIH/OMB)
Black or African American
4 Participants1 Participants5 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
3 Participants7 Participants10 Participants
Region of Enrollment
United States
7 participants10 participants17 participants
Sex: Female, Male
Female
4 Participants7 Participants11 Participants
Sex: Female, Male
Male
3 Participants3 Participants6 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 70 / 10
other
Total, other adverse events
5 / 76 / 10
serious
Total, serious adverse events
0 / 70 / 10

Outcome results

Primary

Median Difference in CD4 Cell Response to Intrabronchial Instillation of Tuberculin Purified Protein Derivative (PPD)

Median difference in CD4 cell response to intrabronchial instillation of Tuberculin Purified Protein Derivative (PPD) using flow cytometry. The frequency of (Mycobacterium tuberculosis) Mtb-specific T cells was measured by intracellular cytokine staining for Interferon Gamma (IFNγ) and Tumor Necrosis Factor (TNF) after in vitro restimulation of Peripheral Blood Mononuclear Cells (PBMC) and Bronchoalveolar Lavage (BAL) cells with PPD or Mtb-derived peptide megapools.

Time frame: Day 5 and Day 21

Population: Cryo-recovery of cells obtained from one participant was unsuccessful; therefore, analysis could not be performed.

ArmMeasureGroupValue (MEDIAN)
Arm 1: Healthy Volunteer Participants With Confirmed Latent Tuberculosis Infection (LTBI)Median Difference in CD4 Cell Response to Intrabronchial Instillation of Tuberculin Purified Protein Derivative (PPD)Day 55.26 % Antigen Specific T cells
Arm 1: Healthy Volunteer Participants With Confirmed Latent Tuberculosis Infection (LTBI)Median Difference in CD4 Cell Response to Intrabronchial Instillation of Tuberculin Purified Protein Derivative (PPD)Day 2129.9 % Antigen Specific T cells
Arm 2: Healthy Volunteer Participants With Confirmed Non-Latent Tuberculosis Infection (LTBI)Median Difference in CD4 Cell Response to Intrabronchial Instillation of Tuberculin Purified Protein Derivative (PPD)Day 50.725 % Antigen Specific T cells
Arm 2: Healthy Volunteer Participants With Confirmed Non-Latent Tuberculosis Infection (LTBI)Median Difference in CD4 Cell Response to Intrabronchial Instillation of Tuberculin Purified Protein Derivative (PPD)Day 212.92 % Antigen Specific T cells
p-value: 0.05714Wilcoxon (Mann-Whitney)
Secondary

Median Difference in the Standard Uptake Value (SUV)

Median difference in the Standard Uptake Value (SUV) in the pulmonary parenchyma and thoracic lymph nodes with positron emission tomography combined with chest computed tomography (PET-CT)

Time frame: Baseline (Up to -7 days prior to PPD instillation), Day 4 and Day 20

Source: ClinicalTrials.gov · Data processed: May 28, 2026