Asthma, Healthy
Conditions
Brief summary
The purpose of this study is to characterize adult subjects regarding their history of allergy and asthma, clinical manifestations of asthma, and exposures and conditions that may influence asthma severity and control. Assessments include baseline medical history, lung function tests, questionnaires, and collection of specimens for phenotypic characterization.
Detailed description
This is a prospective, observational study in which approximately 200 subjects will be enrolled, including healthy controls, atopic controls without asthma, and patients with stable asthma (n = 150). Among asthmatics, 2/3 will be on regular inhaled corticosteroid therapy and 1/3 will not be taking inhaled corticosteroids. Subjects who meet study criteria will undergo phenotypic characterization in multiple domains, including evaluation of lung function, assessments of asthma/allergy history, asthma triggers, asthma symptom control, environmental microbial exposures and dietary intake. Oral rinse, sputum, stool, urine and blood specimens will be collected for microbiome-related analyses, including molecular and culture-based assays, metabolite studies, and to relate these to markers of inflammation and immune function. The overall goal is to enroll a cohort of well-characterized asthmatic and non-asthmatic control subjects to enable mechanism-oriented studies of how members of the airway microbiota and possibly also gut microbiota influence phenotypes of adult asthma.
Interventions
None listed
Sponsors
National Institute of Allergy and Infectious Diseases (NIAID)
University of Michigan
Study design
Observational model
CASE_CONTROL
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
1. For all subjects: Inclusion criteria: \- Men/Women, ages 18-75, with or without current asthma, are eligible to be screened.
Exclusion criteria
* Cigarette smoking history of \>30 total pack-years * Current use of other smoked products or recreational drugs (e.g. pipes, cigars, e-cigarettes, other illicit drugs) * History of lung disease other than asthma * Recent upper respiratory tract infection treated with antibiotics within 8 weeks of visit 1 * Recent antibiotic use (except topical or ocular) within 8 weeks of visit 1 (chronic antibiotic use for asthma management allowed) * Currently pregnant or breast-feeding * Other medical conditions or treatments that may increase subject risk or affect study results, based on study physician judgment. These include the following: significant cardiovascular disease(+/- active symptoms), arrhythmia, or stroke, active cancer, post-organ transplant * Any other condition for which subject is taking immunosuppressive therapies (except steroids for asthma) * History of allergy to albuterol or methacholine 2. For asthma subjects only: Note: Enrollment target is for 90 asthmatics already taking inhaled corticosteroids prescribed by their physician (any formulation and dose) and 60 subjects who are not currently using inhaled corticosteroid. Additional inclusion criteria: * History of asthma symptoms within the last 2 years (e.g. wheeze, shortness of breath, etc.) * Evidence of stable asthma as assessed by initial screening * No changes in asthma medications within 30 days of visit 1 * Methacholine PC20 (dose at which there is a 20 percent change) ≤ 8 mg/ml (for those asthmatics on inhaled steroids, PC20 ≤ 16 mg/ml), or change in FEV1 (forced expiratory volume in first second of spirometry effort)≥ 12% after 4 puffs of albuterol on reversibility testing (or PI discretion) * If negative methacholine challenge or no evidence of bronchodilator reversibility, a strong history of physician-diagnosed/physician-managed asthma may allow for study inclusion, based on PI's judgement or discretion. * Individuals with a history of physician-diagnosed asthma who have had bronchodilator reversibility testing or methacholine challenge performed within 60 days of screening may be enrolled and these existing test results used in lieu of repeating the same test at visit 1 or visit 2. Additional
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| To characterize adult subjects with asthma in multiple domains, including disease severity and control, patterns of airway inflammation, microbial exposures and patterns of airway and gut microbial colonization | Day 1 for the first one and up to 60 days |
Secondary
| Measure | Time frame |
|---|---|
| To evaluate differences in airway and gut microbiota composition related to inhaled corticosteroid use (ICS) among asthmatics already regularly taking ICS, asthmatics not taking ICS, and healthy controls | Day 1 for the first one and up to 60 days |
Other
| Measure | Time frame |
|---|---|
| To apply culture and molecular methods to study functions of asthma-associated airway microbiota in corticosteroid-enriched environments | Day 1 for the first one and up to 60 days |
| To evaluate the temporal stability of the airway microbiome in asthmatic and healthy subjects | Day 1 for the first one and up to 60 days |
| To explore relationships between airway and gut microbiome composition in asthma, including among obese subjects | Day 1 for the first one and up to 60 days |
Countries
United States
Outcome results
None listed