BACKGROUND: There is an increasing need for allergen inhalation systems to perform basic clinical research and test anti-allergic drugs under well-controlled conditions. This requires stability of environmental conditions like temperature and humidity, as well as allergen concentration and reproducible induction of allergic symptoms. OBJECTIVE: The aim of this study was to validate an environmental exposure unit for controlled human pollen inhalation studies in participants with seasonal allergic rhinitis. METHODS: Temperature, relative humidity, and air flow rate were kept constant with an air conditioning system. Pollen atmosphere was generated using a specially designed feeding system and monitored online by laser counter and offline using rotating rod samplers. Efficacy (total nasal symptom score, nasal air flow rate, nasal secretion) and safety (lung function) parameters were evaluated at different pollen concentrations and repeated allergen challenges. RESULTS: Temperature, humidity, and air flow rate in the environmental exposure unit remained constant within a range of <2%. The spatial distribution and the temporal stability of the pollen concentration varied only slightly over 4 h (+/-10% and <4%, respectively). Dose-dependent induction of allergic rhinitis symptoms, reduction in nasal air flow rate, and increase in nasal secretion were observed over time. These effects were reproducible from day to day. Lung function remained clinically normal at all concentrations and from day to day. CONCLUSIONS: Thus, pollen exposure in the environmental exposure unit is an effective, reproducible, safe, and suitable method for single-centre clinical studies on the efficacy of anti-allergic treatment or basic clinical research.
BACKGROUND: There is an increasing need for allergen inhalation systems to perform basic clinical research and test anti-allergic drugs under well-controlled conditions. This requires stability of environmental conditions like temperature and humidity, as well as allergen concentration and reproducible induction of allergic symptoms. OBJECTIVE: The aim of this study was to validate an environmental exposure unit for controlled human pollen inhalation studies in participants with seasonal allergic rhinitis. METHODS: Temperature, relative humidity, and air flow rate were kept constant with an air conditioning system. Pollen atmosphere was generated using a specially designed feeding system and monitored online by laser counter and offline using rotating rod samplers. Efficacy (total nasal symptom score, nasal air flow rate, nasal secretion) and safety (lung function) parameters were evaluated at different pollen concentrations and repeated allergen challenges. RESULTS: Temperature, humidity, and air flow rate in the environmental exposure unit remained constant within a range of <2%. The spatial distribution and the temporal stability of the pollen concentration varied only slightly over 4 h (+/-10% and <4%, respectively). Dose-dependent induction of allergic rhinitis symptoms, reduction in nasal air flow rate, and increase in nasal secretion were observed over time. These effects were reproducible from day to day. Lung function remained clinically normal at all concentrations and from day to day. CONCLUSIONS: Thus, pollen exposure in the environmental exposure unit is an effective, reproducible, safe, and suitable method for single-centre clinical studies on the efficacy of anti-allergic treatment or basic clinical research.
Authors: Sarah K Wise; Sandra Y Lin; Elina Toskala; Richard R Orlandi; Cezmi A Akdis; Jeremiah A Alt; Antoine Azar; Fuad M Baroody; Claus Bachert; G Walter Canonica; Thomas Chacko; Cemal Cingi; Giorgio Ciprandi; Jacquelynne Corey; Linda S Cox; Peter Socrates Creticos; Adnan Custovic; Cecelia Damask; Adam DeConde; John M DelGaudio; Charles S Ebert; Jean Anderson Eloy; Carrie E Flanagan; Wytske J Fokkens; Christine Franzese; Jan Gosepath; Ashleigh Halderman; Robert G Hamilton; Hans Jürgen Hoffman; Jens M Hohlfeld; Steven M Houser; Peter H Hwang; Cristoforo Incorvaia; Deborah Jarvis; Ayesha N Khalid; Maritta Kilpeläinen; Todd T Kingdom; Helene Krouse; Desiree Larenas-Linnemann; Adrienne M Laury; Stella E Lee; Joshua M Levy; Amber U Luong; Bradley F Marple; Edward D McCoul; K Christopher McMains; Erik Melén; James W Mims; Gianna Moscato; Joaquim Mullol; Harold S Nelson; Monica Patadia; Ruby Pawankar; Oliver Pfaar; Michael P Platt; William Reisacher; Carmen Rondón; Luke Rudmik; Matthew Ryan; Joaquin Sastre; Rodney J Schlosser; Russell A Settipane; Hemant P Sharma; Aziz Sheikh; Timothy L Smith; Pongsakorn Tantilipikorn; Jody R Tversky; Maria C Veling; De Yun Wang; Marit Westman; Magnus Wickman; Mark Zacharek Journal: Int Forum Allergy Rhinol Date: 2018-02 Impact factor: 3.858