title: Defining pollen exposure times for clinical trials of allergen immunotherapy for pollen-induced rhinoconjunctivitis - an EAACI position paper.
abstract: BACKGROUND
  Clinical efficacy of pollen allergen immunotherapy (AIT) has been broadly documented in randomized controlled trials. The underlying clinical endpoints are analysed in seasonal time periods predefined based on the background pollen concentration. However, any validated or generally accepted definition from academia or regulatory authorities for this relevant pollen exposure intensity or period of time (season) is currently not available. Therefore, this Task Force initiative of the European Academy of Allergy and Clinical Immunology (EAACI) aimed to propose definitions based on expert consensus.
  
  
  METHODS
  A Task Force of the Immunotherapy and Aerobiology and Pollution Interest Groups of the EAACI reviewed the literature on pollen exposure in the context of defining relevant time intervals for evaluation of efficacy in AIT trials. Underlying principles in measuring pollen exposure and associated methodological problems and limitations were considered to achieve a consensus.
  
  
  RESULTS
  The Task Force achieved a comprehensive position in defining pollen exposure times for different pollen types. Definitions are presented for 'pollen season', 'high pollen season' (or 'peak pollen period') and 'high pollen days'.
  
  
  CONCLUSIONS
  This EAACI position paper provides definitions of pollen exposures for different pollen types for use in AIT trials. Their validity as standards remains to be tested in future studies.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Medical Faculty Mannheim, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany.|Center for Rhinology and Allergology, Wiesbaden, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Pfaar
authors.affiliation: Aerobiology and Pollen Information Research Unit, Department of Oto-Rhino-Laryngology, Medical University of Vienna, Vienna, Austria.
authors.forename: K
authors.initials: K
authors.lastname: Bastl
authors.affiliation: Aerobiology and Pollen Information Research Unit, Department of Oto-Rhino-Laryngology, Medical University of Vienna, Vienna, Austria.
authors.forename: U
authors.initials: U
authors.lastname: Berger
authors.affiliation: ZAUM, Center of Allergy & Environment, Helmholtz Center Munich/Technische Universität München, Member of the German Center for Lung Research (DZL), Munich, Germany.|Kühne Foundation, Christine Kühne-Center for Allergy Research and Education (CK-CARE), Munich, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Buters
authors.affiliation: Section of Allergy and Clinical Immunology, Imperial College London, London, UK.|National Heart & Lung Institute, Royal Brompton Hospital, London, UK.
authors.forename: M A
authors.initials: MA
authors.lastname: Calderon
authors.affiliation: Federal Office of Meteorology and Climatology MeteoSwiss, Payerne, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Clot
authors.affiliation: ZAUM, Center of Allergy & Environment, Helmholtz Center Munich/Technische Universität München, Member of the German Center for Lung Research (DZL), Munich, Germany.|Department of Dermatology and Allergy Biederstein, Technical University of Munich (TUM), Munich, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Darsow
authors.affiliation: Département de Pneumologie et Addictologie, Hôpital Arnaud de Villeneuve, University Hospital of Montpellier, Montpellier, France.|UPMC Paris 06, UMR-S 1136, IPLESP, Equipe EPAR, Sorbonne Universités, Paris, France.
authors.forename: P
authors.initials: P
authors.lastname: Demoly
authors.affiliation: Section of Allergy and Clinical Immunology, Imperial College London, London, UK.
authors.forename: S R
authors.initials: SR
authors.lastname: Durham
authors.affiliation: Department of Botany, Ecology and Plant Physiology, University of Córdoba, Córdoba, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Galán
authors.affiliation: Federal Office of Meteorology and Climatology MeteoSwiss, Zurich, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Gehrig
authors.affiliation: Section of Allergology, Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Gerth van Wijk
authors.affiliation: ALC, Allergy Learning and Consulting, Copenhagen, Denmark.
authors.forename: L
authors.initials: L
authors.lastname: Jacobsen
authors.affiliation: Center for Rhinology and Allergology, Wiesbaden, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Klimek
authors.affiliation: Finnish Meteorological Institute, Helsinki, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Sofiev
authors.affiliation: RNSA (Réseau National de Surveillance Aérobiologique), Brussieu, France.
authors.forename: M
authors.initials: M
authors.lastname: Thibaudon
authors.affiliation: Foundation German Pollen Information Service, Berlin, Germany.
authors.forename: K C
authors.initials: KC
authors.lastname: Bergmann
mesh_terms: D002986:Clinical Trials as Topic; D003233:Conjunctivitis, Allergic / Q000175:diagnosis / Q000276:immunology* / Q000628:therapy*; D003888:Desensitization, Immunologic / Q000379:methods; D004306:Dose-Response Relationship, Immunologic; D004781:Environmental Exposure / Q000009:adverse effects*; D006801:Humans; D011058:Pollen / Q000276:immunology*; D017410:Practice Guidelines as Topic; D006255:Rhinitis, Allergic, Seasonal / Q000175:diagnosis / Q000276:immunology* / Q000628:therapy*; D012621:Seasons; D063189:Symptom Assessment; D013997:Time Factors
keywords: allergen immunotherapy; pollen concentration; pollen exposure; pollen season definition; randomized controlled trials