Asthma, Mucus; Plug, Tracheobronchial
Conditions
Keywords
Asthma, Mucus Plug, Bronchoscopy, CT Scan
Brief summary
This is a single center study of 60 subjects including those with asthma and mucus plugging, those with asthma and without mucus plugging, and healthy controls. Screening data will be reviewed to determine participant eligibility. Participants who meet all inclusion criteria will participate in image-guided bronchoscopy ("virtual navigation bronchoscopy" \[VNB\]) to sample airway biospecimens in mucus plugged and control airways.
Detailed description
This is a single center study of 60 subjects. The investigators will enroll 30 subjects with asthma who demonstrate mucus plugging on a screening CT lung scan, 15 subjects with asthma without mucus plugging, and 15 healthy controls. The healthy controls and subjects with asthma but without mucus plugging with also undergo CT scans to confirm that their lungs aren't obstructed by mucus. Screening data will be reviewed to determine participant eligibility. Participants who meet all inclusion criteria will participate in image-guided bronchoscopy ("virtual navigation bronchoscopy" \[VNB\]) to sample airway biospecimens in mucus plugged and control airways. Subjects will participate in up to 5 study visits at the Airway Clinical Research Center.
Interventions
RADIATIONMultidetector Computed Tomography (MDCT) Scan
This is a low-dose CT scan of the chest using no contract material.
PROCEDUREVirtual Navigation Bronchoscopy (VNB)
This is a procedure where a camera will be inserted into the lung in order to guide sample collection of bronchoalveolar lavages, bronchail brushes and endobronchial biopsies.
Sponsors
University of California, San Francisco
National Institutes of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
Group 1: Healthy Controls Inclusion Criteria: * Male or female between the ages of 18 and 70 years at Visit 1 and at least 50% whose age is \> 40 years (to ensure age balance among groups and anticipating that group 3 subjects will be older). * Written informed consent obtained from subject and ability for subject to comply with the requirements of the study. * Able to perform reproducible spirometry according to ATS criteria.
Exclusion criteria
* Upper respiratory tract infection (URI) within the previous 6 weeks. * History of lung disease. * Smoking of tobacco or other recreational inhalants in last month and/or \>10 pack-year smoking history. * Currently pregnant. * History of allergic rhinitis. * Laboratory evidence of atopy (blood eosinophils \> 0.4 cells/dL, IgE \> 165 IU/mL) * History of unstable cardiovascular disease. * BMI \> 45 * Currently taking anticoagulants. Group 2: Asthmatic Subjects without Mucus Plugs Inclusion Criteria: * Male or female between the ages of 18 and 70 years at Visit 1 and at least 50% whose age is \> 40 years (to ensure age balance among groups and anticipating that group 3 subjects will be older). * Written informed consent obtained from subject and ability for subject to comply with the requirements of the study. * Able to perform reproducible spirometry according to ATS criteria. * Physiological evidence of airflow obstruction (FEV1 bronchodilator reversibility of ≥ 12% or hyperreactivity to methacholine reflected by a methacholine PC20 ≤ 16 mg/mL). Historical methacholine data from previous studies conducted in the past 5 years at the UCSF ACRC will be allowed. * Clinical history of asthma per patient report or medical record. * Asthma requiring treatment with inhaled corticosteroids (ICS) for 3 months or greater.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Difference in eosinophil percentage in broncheoalveolar biospecimens between asthmatic and non-asthmatic airways | 6 months | The investigators will examine differences in type-2 inflammatory markers in bronchoalveolar biospecimens. Eosinophils are an indicator of type 2 inflammation in bronchial lavage samples. Indicators of airway inflammation will be compared with healthy control biospecimens and those of non-mucus plugged asthmatics. |
| Difference in gene expression of genes that mark IL-13 activation between asthmatic and non-asthmatic airways | 6 months | Genes such as periostin, CLCA1, and Serpin B2 will be analyzed for expression in epithelial cell brushings. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORJohn Fahy, MD, MSc
University of California, San Francisco
Outcome results
None listed