title: Blocking antibody is generated in allergic rhinitis patients during specific immunotherapy using standardized Japanese cedar pollen extract.
abstract: BACKGROUND
  Japanese cedar pollen is by far the most important cause of allergic rhinitis in Japan. In this study, we assessed the induction of blocking antibody during specific immunotherapy (SIT) using a recently standardized allergen extract from Japanese cedar pollen.
  
  
  METHODS
  Basophils from nonallergic subjects were passively sensitized with serum samples prepared from pollinosis patients before and after SIT; all patients showed good clinical efficacy. The cells were then stimulated with the standardized allergen, and histamine release was measured. In most experiments, the basophil stimulation buffer contained 1% serum.
  
  
  RESULTS
  Pollinosis patients' sera obtained both before and after SIT showed essentially similar sensitizing capacity for basophils. Basophil degranulation in response to a relatively low concentration of pollen extract was effectively suppressed by addition of post-SIT serum samples, indicating the presence of blocking antibody. The blocking antibody was IgG, and its potency varied widely among the donor patients.
  
  
  CONCLUSIONS
  The standardized allergen extract from Japanese cedar pollen is useful not only for clinical application in SIT, but also for testing for induction of blocking antibody during SIT.
authors.affiliation: Department of Allergy and Rheumatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Kawakami
authors.forename: Rikiya
authors.initials: R
authors.lastname: Koketsu
authors.forename: Maho
authors.initials: M
authors.lastname: Suzukawa
authors.forename: Mizuho
authors.initials: M
authors.lastname: Nagao
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Hiraguchi
authors.forename: Reiko
authors.initials: R
authors.lastname: Tokuda
authors.forename: Takao
authors.initials: T
authors.lastname: Fujisawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nagase
authors.forename: Ken
authors.initials: K
authors.lastname: Ohta
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Masao
authors.initials: M
authors.lastname: Yamaguchi
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology; D018926:Anti-Allergic Agents / Q000627:therapeutic use; D000906:Antibodies / Q000097:blood*; D001491:Basophils / Q000276:immunology; D002648:Child; D032485:Cryptomeria / Q000276:immunology*; D005260:Female; D006801:Humans; D007167:Immunotherapy; D007564:Japan; D008297:Male; D008517:Phytotherapy; D010936:Plant Extracts / Q000627:therapeutic use; D011058:Pollen / Q000737:chemistry / Q000276:immunology*; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology / Q000628:therapy*
chemical_list: D000485:Allergens; D018926:Anti-Allergic Agents; D000906:Antibodies; D010936:Plant Extracts