Allergy, Asthma
Conditions
Keywords
Asthma, Cat allergy, Environmental Exposure Chamber, Air cleaner
Brief summary
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
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.
Interventions
DEVICEActive intense Pure Air XL air cleaner
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
DEVICEPlacebo Intense Pure Air XL air cleaner
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.
Sponsors
Alyatec
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Investigator)
Intervention model description
Randomized, cross-over, double-blind placebo-controlled study including 24 cat-asthmatic patients with GINA 1 asthma.
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Frequency of early asthmatic response | Week 9 | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Frequency of late asthmatic response | Week 9 | 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. |
| Severity of early and/or late asthmatic response | Week 9 | 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. |
| Difference of asthma symptoms during exposure to cat allergen with active air cleaners versus placebo. | Week 9 | 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). |
| Difference of rhinitis symptoms during exposure to cat allergen with active air cleaners versus placebo. | Week 9 | 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). |
| Difference of conjunctivitis symptoms during exposure to cat allergen with active air cleaners versus placebo. | Week 9 | 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). |
Countries
France
Outcome results
None listed