Define and characterize the neutrophilic phenotype of severe asthma.
Neutrophilic asthma (NA) is the asthma phenotype less known, causes a severe disease and does not have a specific treatment. Research on the neutrophilia mechanisms, new neutrophil (NEU) types and bronchial microbiome, can provide an opportunity to better understand the NA pathogenesis. OBJECTIVES: 1. To describe the clinical characteristics of NA and its sub-phenotypes (SUBSTUDY 1); 2. To determine the NEU types associated with the NA and its sub-phenotypes (SUBSTUDY 2); and 3. To identify the bronchial microbiological flora of the NA, specifically related to lung microbiome and the immune response against Chlamydia Pneumoniae (SUBSTUDY 3). METHODS: Multicenter prospective study including 100 patients with severe asthma (GINA/GEMA criteria): 50 with non-neutrophilic asthma (\<65% NEU in induced sputum \[IS\]); and 50 with NA (\> 64% NEU in IS). SUBSTUDY 1: clinical variables (years of evolution, exacerbations, asthma control test, mini asthma quality of life questionnary), comorbidities (GERD, nasal polyposis, obesity, ASS), pulmonary function (FEV1, exhaled fraction of nitric oxide, total lung capacity, Aspergillus), prick-test and CT scan chest; SUBSTUDY 2 (in IS and plasma): apoptotic index by means NE culture and flux cytometer (Annexin-V-FITC), NEU phenotype by surface markers (CD16, CD66b, CD62L, HLADR, CD177, CD11b, CD63, CXCR2, CXCR4) with density gradient study and determination of cytokines (IL-6, IL-8, IL-17, IL-1, IL-22) by ELISA; SUBSTUDY 3 (in IS): bronchial microbiome for 16 subunit rRNA by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt), and anti-Chlamydia Pneumoniae Immunoglobuling A by ELISA.
Study Type
OBSERVATIONAL
Enrollment
10
Characterization with flow cytometry of the phenotype of the neutrophils isolated in the sputum, microbiome
Hospital de la Santa Creu i Sant Pau. Carrer Mas Casanovas 90.
Barcelona, Spain
Hospital de la Santa Creu i Sant Pau
Barcelona, Spain
Phenotype of neutrophils
To determine the types of neutrophils (in induced sputum and blood) associated with neutrophilic asthma and its subphenotypes according to flow cytometry
Time frame: 24 hours
Microbiome analysis
To analyse the bronchial microbiological flora of neutrophilic asthma
Time frame: 6 months
Clinical demographic characteristics
To describe the clinical characteristics and natural history of the neutrophilic asthma and its subphenotypes
Time frame: 1 year
Demographic characteristics
To describe demographic characteristics
Time frame: 1 year
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