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

Validation Study of the ALYATEC Allergen Exposure Chamber by Determining the Concentration of House Dust Mite Allergen Inducing Early and/or Late Bronchial Response in Asthmatic Subjects Allergic to Mite

This is a randomized, double blind, cross-over study designed to determine the concentration of airborne house dust mite allergen inducing bronchial response in asthmatic subjects allergic to mite, 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 house dust mite allergen in Alyatec EEC.

Inclusion Criteria:

• Subjects having signed the informed consent
• Subjects affiliated to a social security scheme
• Positive metacholine test
• FEV1 value > 70% of theoretical FEV1 value
• Asthma Control Test (ACT) ≥ 20/25 in 4 weeks prior to EEC exposure

Group A:

• Mild allergic asthma to HDM (GINA 1 or 2) with associated rhinitis and/or conjunctivitis.
• Positive skin prick-test to Dpt and Df (wheal diameter >5 mm compared to the negative control)
• Specific immunoglobulin E (IgE) for Dpt and Df > 0.7 kU/L

Group B:

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

Exclusion Criteria:

• Uncontrolled asthma
• Asthma Control Test (ACT) < 20/25 in 4 weeks prior to EEC exposure
• Use of oral corticosteroids in the 4 weeks preceding inclusion in the study
• Use of biotherapy in the 4 months preceding inclusion in the study
• 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
• History of Acute Severe Asthma requiring hospitalization in intensive care or intubation
• Desensitization to dust mite allergens in the last 5 years
• Sensitization to allergens in the indoor environment (cat allergens or molds) with obvious exposure to these allergens
• Active tobacco: plus 10 cigarettes / day and tobacco history of +10 PA
• Uncontrolled systemic arterial hypertension
• Recent myocardial infarction (<3 months)
• Recent stroke (<3 months)
• Known arterial aneurysm
• Epilepsy under treatment
• Progressive tumor pathology
• Chronic renal pathology
• Hypersensitivity to one of the excipients used
• Subjects who participated in another clinical study in the three months prior to inclusion