Validation of Strasbourg Environmental Exposure Chamber ALYATEC in Cat Allergic Subjects With Asthma

Validation Study of the ALYATEC Allergen Exposure Chamber (EEC) by Determining the Concentration of Cat Allergen Inducing Early and/or Late Bronchial Response in Asthmatic Subjects Allergic to Cat

This is a randomized, double blind, cross-over study designed to determine the concentration of airborne cat allergen inducing bronchial response in asthmatic subjects allergic to cat, during allergen exposures in the Alyatec environmental exposure chamber (EEC).

The study was also designed to validate the specificity of the asthmatic reaction induced by exposure to airborne cat allergen in Alyatec EEC.

Inclusion Criteria:

• Subjects having signed the informed consent
• Subjects affiliated to a social security scheme
• Non-specific bronchial hyperreactivity (HRBNS) assessed by a positive methacholine test
• FEV1 value > 70% of theoretical FEV1 value
• Asthma Control Test (ACT) ≥ 20/25 in 4 weeks prior to EEC exposure
• Women of childbearing potential should have a negative pregnancy test throughout the study period with effective contraception.

Group A:

• Cat allergic asthma (GINA 1, 2) associated with rhinitis and / or conjunctivitis symptoms triggered during an exposure to a cat.
• Positive skin prick-test to cat allergen extract (wheal diameter >3 mm compared to the negative control) Specific immunoglobulin E (IgE) for cat allergen > 0.7 kU/L

Group B:

• Mild allergic asthma (GINA 1 or 2) not sensitized to cat allergen with associated rhinitis and/or conjunctivitis.
• Negative skin prick-test and specific IgE for cat allergen
• Positive skin prick-test and specific IgE for another allergen.

Exclusion Criteria:

• Uncontrolled asthma, ACT asthma control questionnaire less than 20, in the last 4 weeks
• Uncontrolled asthma 2 weeks after interruption of LABA
• Long-term treatment by LABA, within 2 weeks prior to inclusion
• Existence of a severe obstructive syndrome with FEV1 <70% of the theoretical value
• Obstruction triggered by spirometric evaluations
• Hospitalization for asthma or exacerbation in the last 4 weeks
• Subjects treated with oral corticosteroids in the 4 weeks prior to inclusion in the study
• History of severe acute asthma requiring hospitalization in intensive care or intubation
• Subjects treated with biotherapy in the 4 months prior to inclusion in the study
• Presence of a cat at home, or daily exposure to cat allergens
• Desensitization to cat allergens in the last 6 months
• Active tobacco: plus 10 cigarettes / day or tobacco history plus 10 PA