title: [Evaluation of antigen specific IgE responses in Japanese asthmatics and non-asthmatics].
abstract: BACKGROUND
  An increase in the prevalence of asthma does not seem to be comparable to the dramatic increase of atopy for the last two decades in Japan. Atopy is considered an important risk factor for asthma. It is, however, suggested that asthma itself may be responsible for the increased overall IgE responsiveness. We examined the significance of IgE responsiveness in asthma.
  
  
  METHODS
  We studied 265 healthy controls and 275 patients with asthma. Total serum IgE levels and levels of antigen-specific IgE antibody to mite (D. farinae), cat, dog, timothy, and Candida spp. were determined. We defined atopy by positive RAST (>0.35UA/ml) or MAST scores (>1.0 lumicount) to at least one inhaled allergen. Frequencies of atopic subjects and frequencies of subjects sensitized to each allergen in atopic subjects were compared between the asthmatics and controls. All comparisons were made in younger (<41 yrs) and older (> = 41 yrs) groups, separately.
  
  
  RESULTS
  In younger non-asthmatics, 76.5% (104/136) were atopic. The frequency of atopy was significantly higher in asthmatic subjects compared to non-asthmatics in both younger and older groups. In atopic subjects, older asthmatics were sensitized to animals more frequently than older controls. Although the frequency of subjects sensitized to mite did not differ between asthmatics and controls both in younger and older atopic subjects, asthmatics sensitized to mite had higher titers of specific IgE antibody to mite compared to those of controls sensitized to mite. Even non-atopic asthmatics had higher levels of total IgE compared to non-atopic controls.
  
  
  CONCLUSIONS
  Our data may indicate that sensitization to animals and severer sensitizations to mite are risk factors for asthma. However, given the high prevalence of atopy in younger healthy controls, and increased levels of total serum IgE even in non-atopic asthmatics, our findings may reflect the increased overall IgE responsiveness that is inherent in asthma.
authors.affiliation: First Department of Medicine, School of Medicine, Hokkaido University. daicon@med.hokudai.ac.jp
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takahashi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hizawa
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Maeda
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Fukui
authors.forename: Masaharu
authors.initials: M
authors.lastname: Nishimura
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000818:Animals; D000941:Antigens / Q000276:immunology*; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000276:immunology; D001249:Asthma / Q000453:epidemiology / Q000276:immunology*; D060908:CTLA-4 Antigen; D002415:Cats; D004285:Dogs; D045991:Felis; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000453:epidemiology / Q000276:immunology*; D007073:Immunoglobulin E / Q000276:immunology*; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D008925:Mites; D012307:Risk Factors
chemical_list: D000941:Antigens; D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D007073:Immunoglobulin E