Asthma, Exacerbation, Microbiome
Conditions
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
Interventions
DIAGNOSTIC_TESTPolymerase Chain Reaction (PCR) for viruses and bacteria in nasal swab
PCR for viruses and bacteria in nasal swab
DIAGNOSTIC_TESTInduced sputum microbiome
Microbiome in induced sputum
Sponsors
Sociedad Española de Neumología y Cirugía Torácica
GlaxoSmithKline
Fundació Institut de Recerca de l'Hospital de la Santa Creu i Sant Pau
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Differences between neutrophilic and non-neutrophilic asthma, with and without frequent exacerbations in bronchial microbiome using 16S rDNA sequencing | 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
| Measure | Time frame | Description |
|---|---|---|
| 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 | Influence of bronchial infections in qualitative and quantitative characteristics of lung microbiome. (Bacterial communities and major bacterial phyla) |
| Changes in absolute and relative abundance of bronchial microbiota over a year using 16S rDNA sequencing | 1 year | Qualitative and quantitative changes of lung microbiome (Bacterial communities and major bacterial phyla) |
| Relationship between lung microbiome andlevels of specific immunoglobulin A of C. pneumoniae, PCR, and immunoglobulin G of aspergillus | 6 months | Relationship between qualitative and quantitative characteristics of lung microbiome with levels of specific IgA C. pneumoniae, PCR, IgG aspergillus |
Countries
Spain
Contacts
Primary ContactAstrid Crespo, PhD
Outcome results
None listed