Validated allergen exposure chamber is plausible tool for the assessment of house dust mite‐triggered allergic rhinitis

Abstract

Background: Allergen exposure chamber (AEC) is a clinical facility that allows exposure to allergenic airborne particles in controlled environment. Although AECs offer stable levels of airborne allergens, the validation of symptoms and other endpoints induced by allergen challenge is key for their recommendation as a plausible tool for the assessment of patients, especially in clinical research. This study aimed to demonstrate the reproducibility of defined clinical endpoints after AEC house dust mite (HDM) challenge under optimal conditions in patients with allergic rhinitis (AR). Method: HDM was distributed at different concentrations. The assessment was subjective by the patients: total nasal symptom score (TNSS), visual analog scale (VAS), and objective by the investigator: acoustic rhinometry, peak nasal inspiratory flow (PNIF), and nasal secretion weight. Safety was assessed clinically and by peak expiratory flow rate (PEFR) and forced expiratory volume in the first second (FEV 1 ).Results: Constant environment: temperature, humidity, and carbon dioxide (CO 2 ) concentration were maintained during all challenges. The concentration of HDM on average remained stable within the targeted values: 1000, 3000, 5000, 7000 particles (p)/m 3 . Most symptoms were observed at concentrations 3000 p/m 3 or higher. The symptoms severity and other endpoints results were reproducible. 5000 p/m 3 , and challenge duration of 120 min were found optimal. The procedure was safe with no lung function abnormalities due to challenge. Conclusion:HDM challenge in ALL-MED AEC offers a safe and reliable method for inducing symptoms in AR patients for the use in controlled clinical studies including allergen immunotherapy.

Sodium Chloride versus Lactose as a Carrier for House Dust Mite Allergen in Allergen Chamber Studies: A Clinical Study to Assess Noninferiority

“…Hossenbaccus et al [3] tested two different allergen concentrations and observed a mean peak TNSS of 5.74 at a modest concentration and 8.17 at a high concentration. Similarly, Zemelka-Wiacek et al [4] documented mean peak TNSS values >6 at higher allergen concentrations and 4–6 at the lowest tested concentration. Khayath et al [9] who also used a spray drying technique with allergen extract and normal saline, reported a positive dose-response relationship: mean TNSS >6 was found in 58% of participants at 15 ng/m 3 , in 63% at 25 ng/m 3 , and in 75% at 46 ng/m 3 Der p1 concentration.…”

“…Allergen material and particle size distributions differ, e.g., the Vienna Challenge Chamber (Austria) reported use of large particles >25 μm from dried raw material [2]. Kingston Environmental Exposure Unit (Canada), GA 2-LEN chamber (Germany), Biogenics Research Chamber (USA), and ALL-MED Allergen Exposure Chamber (Poland) also used dried raw material, though not selected by particle size [3][4][5][6]. In contrast, AARHUS (Denmark) exposure chamber described to have collected dust from office buildings or homes that was subsequently homogenized, with particle sizes <5 μm, dominating during exposure [7,8].…”

Hot topics in allergen immunotherapy, 2023: Current status and future perspective

“…However, an EAACI task force comprising worldwide clinicians, AEC providers and delegates from regulatory authorities has provided overviews of the similarities and differences of current AEC facilities with the aim of further harmonization 129 . An important step in this direction has been the compilation of technical validation data reported by international AEC providers, opening the path for the next step of AEC development, the clinical validation, for example, through a hybrid approach 130,131 …”

“…129 An important step in this direction has been the compilation of technical validation data reported by international AEC providers, opening the path for the next step of AEC development, the clinical validation, for example, through a hybrid approach. 130,131…”

Immunological mechanisms of tolerance: Central, peripheral and the role of T and B cells

“…The allergen exposure chamber is particularly useful for assessing the responses of patients to airborne allergens. By controlling the concentration of allergen released, symptomatic changes of patients across different allergen concentrations may be assessed [ 123 ]. However, the most widely used method is skin prick testing (SPT).…”