Validation of Strasbourg environmental exposure chamber (EEC) ALYATEC ® in mite allergic subjects with asthma

J Asthma. 2020 Feb;57(2):140-148. doi: 10.1080/02770903.2018.1563902. Epub 2019 Mar 28.

Abstract

Objective: Environmental Exposure Chamber (EEC) should have standardized and controlled allergenic and non-allergenic exposures to perform reproducible clinical studies. The aim was to demonstrate that mite exposure in the Alyatec® EEC could induce early (EAR) and/or late asthmatic reactions (LAR) in at least 60% of subjects allergic to mite.Methods: The EEC has a volume of 147-m3 with 20 seats. The nebulized particle number, airborne Der p1, endotoxins, and volatile organic compound (VOC) concentrations were measured. Twenty-four asthmatics allergic to mite were randomly exposed to 15, 25, and 46 ng/m3 Der p1. Specificity was assessed in not mite-sensitized asthmatics.Results: No significant endotoxin or VOC contamination was measured. The mean inter-assay CVs were 12.5% for the airborne particle number and 28.7% for airborne Der p1 concentrations. For the three Der p1 concentrations, at least 88% of the subjects developed EAR and/or LAR, and at least 46% developed a dual response. No reaction occurred with placebo or in the control group. No severe bronchial reaction occurred.Conclusions: The Alyatec® EEC demonstrated a tight control of allergenic and non-allergenic exposures. The EEC was clinically validated, with airborne Der p1 levels close to levels found in natural settings.

Keywords: Mite; asthma; early asthmatic response; environmental experimental chamber; late asthmatic response.

Publication types

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

MeSH terms

  • Adolescent
  • Adult
  • Animals
  • Antigens, Dermatophagoides / pharmacology
  • Arthropod Proteins / pharmacology
  • Asthma / epidemiology*
  • Cross-Over Studies
  • Cysteine Endopeptidases / pharmacology
  • Double-Blind Method
  • Endotoxins / pharmacology
  • Environmental Exposure
  • Female
  • Humans
  • Hypersensitivity / diagnosis*
  • Hypersensitivity / epidemiology*
  • Male
  • Middle Aged
  • Mites*
  • Reproducibility of Results
  • Severity of Illness Index
  • Volatile Organic Compounds / pharmacology
  • Young Adult

Substances

  • Antigens, Dermatophagoides
  • Arthropod Proteins
  • Endotoxins
  • Volatile Organic Compounds
  • Cysteine Endopeptidases
  • Dermatophagoides pteronyssinus antigen p 1