Exacerbations in Neutrophilic Asthma: Influence of Bronchial Microbiome
Trial Snapshot
- Phase
- Not Applicable
- Status
- Recruiting
- Sponsor
- Enrollment
- 40
- Locations
- 1
- Primary Endpoint
- Differences between neutrophilic and non-neutrophilic asthma, with and without frequent exacerbations in bronchial microbiome using 16S rDNA sequencing
Study Overview
Brief Summary
Neutrophilic asthma (NA) is the least known severe asthma phenotype. It is associated with more exacerbations, worse control and impaired lung function. One of its possible etiologies is bronchial infections. The study of bronchial microbiology and its relationship with exacerbations is a new line of research.
Objectives: 1) To analyze bronchial microbiome in patients with AN and non-neutrophilic (ANN), with frequent exacerbations and without exacerbations. 2) To relate the presence of bronchial infections with differences in the microbiome. 3) Correlate the characteristics of the microbiome with other evidence used in exacerbations.
Methods: Prospective study involving 40 non-smoking asthmatics without bronchiectasis (20 with AN and 20 with ANN). Of these, 10 in each group will have frequent exacerbations (>2 rounds of systemic steroids in the last year, of >3 days each) and 10 non- frequent exacerbations. AN will be defined as >65% neutrophils in stable phase sputum. All patients will have two stable visits in which clinical variables, asthma control, lung function and induced sputum samples will be collected (for analysis of bronchial inflammatory cell count and for the study of the microbiome by 16 subunit rRNA). Specific Immunoglobulin A (IgA) for Chlamydia Pneumoniae will be determined. In exacerbations, sputum samples will be collected for culture and nasopharyngeal smears for the study of major respiratory viruses and bacteria by multiple polymerase chain reaction.
Detailed Description
See above
Study Design
- Study Type
- Observational
- Observational Model
- Cohort
- Time Perspective
- Prospective
Eligibility Criteria
- Ages
- 18 Years to 80 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Age between 18 -80
- •Confirmed diagnose of asthma
- •Severe persistent asthma
Exclusion Criteria
- •Respiratory infection during the previous month
- •Other significant lung disease
Outcomes
Primary Outcomes
Differences between neutrophilic and non-neutrophilic asthma, with and without frequent exacerbations in bronchial microbiome using 16S rDNA sequencing
Time Frame: 6 months
Qualitative and quantitative analysis of bronchial microbiome in patients including bacterial communities and major bacterial phyla in neutrophilic and non-neutrophilic asthma, with frequent exacerbations and without exacerbations.
Secondary Outcomes
- Changes in absolute and relative abundance using 16S rDNA sequencing of bronchial microbiota due to asthma exacerbations, in patients with neutrophilic and eosinophilic asthma(1 year)
- Changes in absolute and relative abundance of bronchial microbiota over a year using 16S rDNA sequencing(1 year)
- Relationship between lung microbiome andlevels of specific immunoglobulin A of C. pneumoniae, PCR, and immunoglobulin G of aspergillus(6 months)