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

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