Efficacy of air cleaners in asthmatics allergic to cat in ALYATEC ® environmental exposure chamber

Clin Exp Allergy. 2020 Feb;50(2):160-169. doi: 10.1111/cea.13511. Epub 2019 Nov 6.


Background: Air cleaners have been promoted for respiratory allergic disease prevention, but there is no clear clinical proof of their efficacy in allergic asthma.

Objective: To examine the efficacy of a new air cleaner on early and late asthmatic responses in cat-allergic patients.

Methods: This randomized, cross-over, double-blind placebo-controlled study enrolled 24 cat-asthmatic patients with GINA 1 asthma. At baseline, participants were exposed to 40 ng/m3 of airborne cat allergen for a maximum of 2 hours in ALYATEC® environmental exposure chamber (EEC). All participants were subsequently randomized into two groups that were exposed to cat allergen, either with active then placebo air cleaners or with placebo then active air cleaners with a 3-week interval in the EEC. This study was registered under number (NCT03928561).

Results: Fewer patients experienced an EAR with active air cleaners (seven patients; 29.17%) than placebo (21 patients; 87.50%). The response incidence was lower with active than with placebo air cleaners. A Cox model demonstrated a significant treatment effect (hazard ratio, 0.10; P = .002). Active air cleaners also prevented late asthmatic response: four patients (16.67%) had a late asthmatic response with active air cleaners compared to 11 patients (45.83%) with placebo (Prescott test P = .002). Active air cleaners also decreased the maximal severity of bronchial response (FEV1 decrease of 17.24% with active vs 25.62% with placebo air cleaners; P = .001).

Conclusions: Our present results demonstrated that Intense Pure Air XL® air cleaners significantly prevented early and late asthmatic responses among cat-allergic asthmatics during cat allergen exposure in the ALYATEC® EEC.

Keywords: air cleaners; cat-allergic asthma; environmental exposure chamber.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Air Filters*
  • Air Pollution, Indoor / adverse effects
  • Air Pollution, Indoor / prevention & control
  • Allergens / toxicity*
  • Animals
  • Asthma / immunology
  • Asthma / physiopathology
  • Asthma / prevention & control*
  • Cats
  • Double-Blind Method
  • Environmental Exposure / adverse effects
  • Environmental Exposure / prevention & control*
  • Female
  • Humans
  • Male


  • Allergens

Associated data

  • ClinicalTrials.gov/NCT03928561