The purpose of this study is to evaluate clinical and histological response to bronchial thermoplasty in severe asthma patients.

Bronchial thermoplasty is a new therapeutic tool for severe and uncontrolled asthma patients. Clinical trials have demonstrated clinical benefits regarding quality of life and exacerbations. Animal models suggested the reduction of bronchial smooth muscle as the principal responsible for the clinical benefits observed in asthma patients treated in the clinical trials, although there is little information about its mechanism of action, and limited to a very small number of case reports. Given that the mechanism of action of bronchial thermoplasty is still not well understood, we proposed a biological study in asthma patients treated with bronchial thermoplasty with the purpose to analyze changes in inflammatory markers and histological samples, as well as its correlation with clinical outcomes in real practice.

Inclusion Criteria:

• Patients under 18 years old.
• Severe persistent asthma according to GINA.
• Inhaled corticosteroids and long-acting ß2 agonist (LABA).
• Other medications for asthma, as oral corticosteroids, anti-IgE, theofiline, etc. are also acceptable.
• Asthma Quality of Life Questionnaire (AQLQ) < 7
• Asthma Control Test (ACT) < 19
• ≥ 2 exacerbations in last year

Exclusion Criteria:

• History of cigarette smoking with > 15 pack/years.
• Other respiratory diseases.
• Comorbidity that can justify the symptoms of the patients.
• Life-threating unstable asthma.
• Any contraindication to perform a bronchoscopy (respiratory insufficiency, coagulation abnormalities, allergy to sedative drugs, etc.)