Validation of Strasbourg Environmental Exposure Chamber ALYATEC in Mite Allergic Subjects With Asthma
- Conditions
- Allergic AsthmaAllergy to House DustAllergy
- Interventions
- Other: Exposure to placebo in EECOther: Exposure to three concentrations of HDM allergen in EECOther: Exposure to a single concentration of HDM allergen in EEC
- Registration Number
- NCT04663880
- Lead Sponsor
- Alyatec
- Brief Summary
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.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 27
- 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.
- 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
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description Asthmatic subjects not allergic to house dust mite Exposure to placebo in EEC 13 subjects were exposed first to placebo then to Der p1 concentration of 25 ng/m3. Asthmatic subjects allergic to house dust mite Exposure to placebo in EEC 24 subjects were randomized in a doubleblinded manner into six subgroups. All were exposed first to placebo then in cross over to three different Der p1 concentrations, respectively 15, 25, and 46 ng/m3. Asthmatic subjects allergic to house dust mite Exposure to three concentrations of HDM allergen in EEC 24 subjects were randomized in a doubleblinded manner into six subgroups. All were exposed first to placebo then in cross over to three different Der p1 concentrations, respectively 15, 25, and 46 ng/m3. Asthmatic subjects not allergic to house dust mite Exposure to a single concentration of HDM allergen in EEC 13 subjects were exposed first to placebo then to Der p1 concentration of 25 ng/m3.
- Primary Outcome Measures
Name Time Method Determine the concentration of HDM allergen (in ng/m3 of Der p1) necessary to induce a bronchial response in at least 60% of asthmatic subjects allergic to HDM 10 hours: 4 hours of exposure in the EEC then 6 hours post-exposure. The bronchial response is evaluated by measuring FEV1 value during EEC exposure.
Early asthmatic response (EAR) occurs when a 20% drop in FEV1 is detected during the exposure compared to the pre-exposure FEV1.
Late bronchial response (LAR) occurs when a 15% drop in FEV1 or 20% drop in peak flow is detected 1 to 6h after the EAR.
- Secondary Outcome Measures
Name Time Method Evaluate the specificity of the bronchial response 4 hours of exposure in EEC The specificity of the bronchial response is assessed with the HDM exposure in the EEC of asthmatic subjects non allergic to HDM.
Evaluate the safety of allergenic exposure in EEC 28 hours: 4 hours of exposure in EEC then 24 hours post-exposure Safety is assessed with clinical evaluations performed during the 4h of exposure in the EEC
Evaluate the metrology of the EEC 4 hours of exposure in EEC The metrology is assessed with the measure of allergen concentration and particules diameter thanks to sensors in the chamber.
Evaluate the effect of the exposure on rhinitis symptoms 28 hours: 4 hours of exposure in EEC then 24 hours post-exposure The effect of the exposure on the rhinitis response is assessed with Total Nasal Symptom Score (TNSS).
The TNSS was obtained from the sum of all four individual symptom scores, with a total possible score ranging from 0 (no symptoms) to 12 (maximum symptom intensity).Evaluate the effect of the exposure on conjunctivitis symptoms 28 hours: 4 hours of exposure in EEC then 24 hours post-exposure The effect of the exposure on the conjunctivitis response is assessed with Total Ocular Symptom Score (TOSS).
The TOSS was obtained from the sum of all four individual symptom scores, with a total possible score ranging from 0 (no symptoms) to 12 (maximum symptom intensity).
Trial Locations
- Locations (1)
Alyatec
🇫🇷Strasbourg, Grand Est, France