title: Year-to-year variation in release of Bet v 1 allergen from birch pollen: evidence for geographical differences between West and South Germany.
abstract: BACKGROUND
  The release of the aeroallergen Bet v 1 from pollen is a major determinant in the etiology of allergic airway disease due to birch pollen.
  
  
  OBJECTIVE
  We determined the release of the major birch pollen allergen Bet v 1 from pollen of birch trees growing in 2 different geographic regions in Germany for 2 consecutive years.
  
  
  METHODS
  Catkins were collected during pollination in 2002 and 2003 from 82 healthy trees in South (Munich) and West Germany (North Rhine-Westphalia). The release of Bet v 1 from pollen samples was determined by a Bet v 1-specific ELISA.
  
  
  RESULTS
  Pollen from South Germany released about 3 times more Bet v 1 than those from West Germany in both 2002 and 2003 (p = 0.034 and p = 0.007, respectively). This was independent of the number of pollen during the pollen flight season. In 2003, the release of Bet v 1 from pollen was more than 5 times higher than in 2002 in both regions (South Germany 6.1 times, p < 0.001; West Germany 5.4 times, p = 0.003).
  
  
  CONCLUSIONS
  Despite large individual differences, there seem to be regional and year-to-year variations in Bet v 1 release from birch pollen. Therefore, the combination of pollen count and release of Bet v 1 from this pollen must be assessed to estimate Bet v 1 exposure reliably.
authors.affiliation: Division of Environmental Dermatology and Allergy GSF/TUM, ZAUM-Center for Allergy and Environment, Technical University Munich, Munich, Germany. buters@lrz.tum.de
authors.forename: Jeroen T M
authors.initials: JT
authors.lastname: Buters
authors.forename: Anna
authors.initials: A
authors.lastname: Kasche
authors.forename: Ingrid
authors.initials: I
authors.lastname: Weichenmeier
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schober
authors.forename: Sabrina
authors.initials: S
authors.lastname: Klaus
authors.forename: Claudia
authors.initials: C
authors.lastname: Traidl-Hoffmann
authors.forename: Annette
authors.initials: A
authors.lastname: Menzel
authors.forename: Johannes
authors.initials: J
authors.lastname: Huss-Marp
authors.forename: Ursula
authors.initials: U
authors.lastname: Kramer
authors.forename: Heidrun
authors.initials: H
authors.lastname: Behrendt
mesh_terms: D000328:Adult; D000485:Allergens / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D052179:Antigens, Plant; D029662:Betula / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D005843:Geography; D005858:Germany; D006801:Humans; D008297:Male; D008685:Meteorological Concepts; D008875:Middle Aged; D010940:Plant Proteins / Q000032:analysis*; D011058:Pollen / Q000737:chemistry* / Q000276:immunology; D011852:Radioallergosorbent Test; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology; D012621:Seasons; D012882:Skin Tests; D014197:Trees / Q000502:physiology
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D010940:Plant Proteins