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

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.

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