Efficacy of Air Cleaners in Asthmatics Allergic to Cat in ALYATEC Environmental Exposure Chamber

Study Overview
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Brief Summary
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The aim of this study is to determine the efficacy of Rowenta® Intense Pure Air XL air cleaner on the early and late bronchial response, in cat-allergic asthmatic patients during an allergen exposure in ALYATEC environmental chamber (EEC)

Detailed Description
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A monocentric, double-blind, placebo-controlled, cross-over study conducted outside of the pollen season. The study lasts 3 months for each patient, which includes a screening period, two exposure visits in the Alyatec Environmental Exposure Chamber (EEC) with active or placebo air cleaners, and a follow-up visit. Patients with early asthmatic reaction during baseline exposure are randomly allocated to one of two sequences: active air cleaners /placebo or placebo/active air cleaners. Randomization is balanced (1:1) between the two sequences. There is a 3-week wash-out period between the two exposures.

Official Title
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Efficacy of Air Cleaners in Asthmatics Allergic to Cat in ALYATEC Environmental Exposure Chamber

Conditions
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Asthma, Allergy

Intervention / Treatment
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* Device: Active intense Pure Air XL air cleaner
* Device: Placebo Intense Pure Air XL air cleaner


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Controlled intermittent asthma (step 1 treatment, according to GINA Guideline 2016) with or without association with cat allergy related rhino-conjunctivitis; Sensitization to cat allergen extract as defined by skin prick test for cat extract with a wheal diameter of ≥3 mm greater than negative control (ALK, HØrsholm, Denmark) and specific IgE anti Fel d 1 ≥ 0.7 kU/L ( ImmunoCAP, Thermofisher, Uppsala, Sweden); FEV1 ≥ 70% of the predicted value; No cat exposure at home or outside of the home during the study; Positive methacholine challenge test performed using an AeroDoseur DTF-Atomisor ATO-AD 12 (Saint-Etienne, France); Early asthmatic response during baseline cat allergen exposure. Exclusion Criteria: Uncontrolled asthma, asthma control test inferior to 20 within the 4 weeks preceding the study. Uncontrolled asthma 2 weeks after stopping LABA treatment. LABA treatment within the 2 weeks preceding the study. Severe asthma (> GINA 2) Subject lives with a cat Cat desensibilisation within the 6 previous months. Active smoker

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: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Randomized, cross-over, double-blind placebo-controlled study including 24 cat-asthmatic patients with GINA 1 asthma.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1 - Active air cleaner then Placebo<br>Exposure to cat allergen in the presence of active air cleaners then placebo. 3-week wash-out period between the two exposures. | Device: Active intense Pure Air XL air cleaner<br>* Cat allergen is nebulized in the EEC. When the concentration is stable, air cleaners are switched on. The number of air cleaners placed in the EEC is defined according to the volume of the EEC and the air renewal. Patients are exposed to cat allergen in the presence of active air cleaners in the EEC<br>Device: Placebo Intense Pure Air XL air cleaner<br>* Cat allergen is nebulized in the EEC. When the concentration is stable, placebo air cleaners are switched on. The placebo effect is obtained thanks to the removal of air cleaners filters prior to the exposure. The number of placebo air cleaners placed in the EEC is defined according to the volume of the EEC and the air renewal. Patients are exposed to cat allergen in the presence of placebo air cleaners in the EEC.<br>|
| Experimental: 2 - Placebo then active air cleaner<br>Exposure to cat allergen in the presence of placebo then active air cleaners. 3-week wash-out period between the two exposures. | Device: Active intense Pure Air XL air cleaner<br>* Cat allergen is nebulized in the EEC. When the concentration is stable, air cleaners are switched on. The number of air cleaners placed in the EEC is defined according to the volume of the EEC and the air renewal. Patients are exposed to cat allergen in the presence of active air cleaners in the EEC<br>Device: Placebo Intense Pure Air XL air cleaner<br>* Cat allergen is nebulized in the EEC. When the concentration is stable, placebo air cleaners are switched on. The placebo effect is obtained thanks to the removal of air cleaners filters prior to the exposure. The number of placebo air cleaners placed in the EEC is defined according to the volume of the EEC and the air renewal. Patients are exposed to cat allergen in the presence of placebo air cleaners in the EEC.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Frequency of early asthmatic response | In subjects exposed in the EEC to an average cat allergen concentration of 40 ng/m3 (Feld1) in presence of an active air cleaner compared to a placebo. Early asthmatic response is defined by a drop of at least 20% compared to baseline FEV1. | Week 9 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Frequency of late asthmatic response | Late asthmatic response is defined by a 15% drop of FEV1 compared to baseline FEV1 between 1h and 6h after the end of the allergen exposure. | Week 9 | 
| Severity of early and/or late asthmatic response | Evaluated by the maximum percentage of drop in FEV1. It was measured in subjects exposed to cat allergen with active air cleaners compared to placebo air cleaners. | Week 9 | 
| Difference of asthma symptoms during exposure to cat allergen with active air cleaners versus placebo. | The intensity of asthma symptoms is assessed using the visual analogue scale (VAS). The VAS is based on one question which allows to evaluate the symptoms on a scale from 0 to 10. 0 means no symptoms (best condition) and 10 means high symptoms (worse condition). | Week 9 | 
| Difference of rhinitis symptoms during exposure to cat allergen with active air cleaners versus placebo. | The intensity of rhinitis symptoms is assessed using the TNSS (Total Nasal Symptom Score) nasal self-assessment questionnaire. The score of the TNSS varies from 0 (no symptoms) to 12 (high symptoms). | Week 9 | 
| Difference of rhinitis symptoms during exposure to cat allergen with active air cleaners versus placebo. | The intensity of rhinitis symptoms is assessed using the visual analogue scale (VAS). The VAS is based on one question which allows to evaluate the symptoms on a scale from 0 to 10. 0 means no symptoms (best condition) and 10 means high symptoms (worse condition). A difference of 23 mm between two assessments done before and after exposure is considered as clinically significant. | Week 9 | 
| Difference of conjunctivitis symptoms during exposure to cat allergen with active air cleaners versus placebo. | The intensity of conjunctivitis symptoms is assessed using the TOSS (Total Ocular Symptom Score) conjunctival self-assessment questionnaire. It varies between 0 (no symptoms) and 6 (high symptoms). | Week 9 | 
| Difference of conjunctivitis symptoms during exposure to cat allergen with active air cleaners versus placebo. | The intensity of conjunctivitis symptoms is assessed using the visual analogue scale (conjunctivitis VAS). The VAS is based on one question which allows to evaluate the symptoms on a scale from 0 (no symptoms) to 10 (high symptoms). | Week 9 | 
| Difference of conjunctivitis symptoms during exposure to cat allergen with active air cleaners versus placebo. | The intensity of conjunctivitis symptoms is assessed using Abelson's Score. Abelson's score varies from 0 (no symptoms) to 13 (higher symptoms). A positive conjunctival response is defined by Albelson's Score evaluated by physician above or equal to 5 during allergen exposure. | Week 9 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Asthma, Cat allergy, Environmental Exposure Chamber, Air cleaner