Clinical Validation Study in Allergic Conjunctivitis to Birch Pollen During Allergen Challenge in ALYATEC EEC

Study Overview
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Brief Summary
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This is a single center open study designed to determine the concentration of airborne birch pollen inducing an allergic conjunctivitis response in individuals allergic to birch pollen, during allergen exposures in the Alyatec environmental exposure chamber (EEC).

Official Title
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Validation and Reproducibility Study of the ALYATEC Allergen Exposure Chamber by Determining the Concentration of Birch Pollen Allergen Inducing Conjunctivitis in Subjects Allergic to Birch Pollen.

Conditions
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Allergic Conjunctivitis

Intervention / Treatment
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* Other: Exposure to birch pollen in EEC


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects having signed the informed consent Subjects affiliated to a social security scheme Subjects with birch pollen rhinitis and conjunctivitis with: A history of rhinoconjunctivitis for at least the last 2 consecutive pollen seasons. A positive skin prick-test to birch (wheal diameter >6 mm compared to the negative control), Specific immunoglobulin E (IgE) for birch> 0.1 kIU/l Women of childbearing potential must have a negative pregnancy test during the entire study period with an effective means of contraception: oral contraceptives, intrauterine device, condom with spermicide for at least one month before inclusion in the study and for the duration of the study. At each study visit and each exposure on D1, a urine pregnancy test will be performed. A positive conjunctival provocation test to birch during the screening visit at a dilution of 100IR/ml maximum Exclusion Criteria: Known asthmatic subjects allergic to birch pollen 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 Desensitization to birch pollen in the last 5 years Uncontrolled chronic pathologies (hypertension, cardiac, respiratory, renal pathology). Active autoimmune disease Uncontrolled systemic hypertension Subjects who participated in another clinical study in the three months prior to inclusion Pregnancy and breast feeding Inability to understand and act upon the information provided

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Exposure to birch pollen<br>Step 1: dose validation 16 subjects are exposed for 2 consecutive days (D1 + D2), to the same aerial concentration of Bet v1. The main objective is achieved if the Abelson score is ≥ 5 on J1 or J2. If the main objective is achieved for the 60 ng/m3 concentration, 8 responder subjects will directly perform step 2. If the main objective is not achieved for the 60 ng/m3 concentration, the subjects will be exposed between 7 to 10 days after exposure 1, to an allergen concentration of 120 ng/m3 (Exposure 2: D1 + D2). Step 2: reproducibility Once the allergen concentration has been determined (step 1), 8 of the responder subjects from step 1 are exposed again to this same concentration, during 2 additional exposures (Exposure 3: D1 + D2 and Exposure 4: D1 + D2), at least 7 days apart. A wash-out period of at least 7 days is observed between step 1 and 2. The duration of allergen exposure will be a maximum of 4 hours for all exposures. | Other: Exposure to birch pollen in EEC<br>* Patients are exposed to airborne birch pollen allergen. The duration of each exposure is 4h maximum.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Determine the concentration of birch pollen allergen (in ng/m3 of Bet v1) necessary to induce a conjunctival response in at least 50% of subjects allergic to birch. | A positive conjunctival response is defined by an Abelson score ≥ 5. | 4 hours exposure in EEC | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluate the reproducibility of allergen exposure in the ALYATEC EEC | The reproducibility of the exposure will be assessed by measuring the quantity of birch pollen allergen (ng Bet v1) inducing a conjunctival response during step 2. | 4 hours exposure in EEC | 
| Study the effect of EEC birch pollen exposure on symptoms of rhino-conjunctivitis. | The effect of the exposure on the rhinoconjunctival response will be assessed by Rhinoconjunctivitis Total Symptom Score (RTSS). The RTSS is the sum of 6 rhinoconjunctivitis symptom scores: sneezing, rhinorrhea, nasal pruritus, nasal congestion, ocular pruritus and watery eyes. Each symptom is graded in a 4-point scale as follows: 0: no symptoms, 1: mild symptoms, 2: moderate symptoms, 3: severe symptoms. It ranges from 0 to 18. The lower the score, the better the outcome. | 4 hours exposure in EEC | 
| Study the effect of EEC birch pollen exposure on symptoms of rhinitis | The effect of the exposure on the rhinitis response will be assessed by rhinitis Visual Analogue Scale (VAS). The rhinitis VAS is a measurement of patient's subjective evaluation of symptoms severity. Patients will score the severity of their nasal symptoms on a scale, with 0 meaning no symptoms and 10 meaning the worst symptoms. | 4 hours exposure in EEC | 
| Study the effect of EEC birch pollen exposure on symptoms of conjunctivitis. | The effect of the exposure on the conjunctival response will be assessed by Conjunctivitis Visual Analogue Scale (VAS). The conjunctivitis VAS is a measurement of patient's subjective evaluation of symptoms severity. Patients will score the severity of their ocular symptoms on a scale, with 0 meaning no symptoms and 10 meaning the worst symptoms. | 4 hours exposure in EEC | 
| Measure the amount of particles carrying the allergens. | The amount of particles carrying the allergen will be measured with counters located in the exposure chamber. | 4 hours exposure in EEC | 
| Measure the aerodynamic diameter of the particles carrying the allergens. | The aerodynamic diameter of the particles carrying the allergen will be measured with counters located in the exposure chamber. | 4 hours exposure in EEC | 
| Evaluate changes in mitochondrial respiration | The changes in mitochondrial respiration will be done by evaluating the modifications of the I to IV complex of the mitochondrial respiratory chain, before and after allergen exposure | 4 hours exposure in EEC | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Allergy, Conjunctivitis