Slow recruitment of patients

Asthma is a chronic illness characterized by inflammation of the airways. Severe asthma is defined in the literature as asthma not controlled by medication. In recent years it has become known that severe asthma is a variable disease and has subtypes relating to the age of onset, type of inflammation and allergy, obesity, etc.

Our aim is to characterize the phenotypes of severe asthma population in our clinic and compare the prevalent phenotypes to the phenotypes described before.

Study measures will include the following:

• asthma demographic and symptoms questionnaire
• Validation of proper inhaler technique
• Height, weight measurements
• Forced spirometry and reversibility testing
• DLCO
• Fractional excretion of NO in exhaled breath
• Chest and sinus CT
• Induced sputum analysis
• Complete blood count, electrolytes, immunoglobulin E, Aspergillus Specific IgE
• Skin allergy testing

Inclusion Criteria:

1. Presence of Asthma- typical symptoms and signs accompanied by either: a. obstruction in Spirometry, OR- b. positive methacholine test
2. Regular use of high dose of inhaled corticosteroids (1000 micrograms of fluticasone per day or equivalent) in addition to a long acting beta agonist (LABA).
3. Lack of asthma control- 2 or more exacerbations in the past year- exacerbations defined by hospitalization or care in an emergency department or treatment with systemic glucocorticosteroids for exacerbation of asthma symptoms.

Exclusion Criteria:

1. Presence of another relevant respiratory illness, such as chronic obstructive pulmonary disease (COPD)
2. lack of adherence to medical therapy

Population of petients with severe asthma, described by presence of symptoms despite adequate treatment as described in the following sections.