title: Antiulcer drugs promote oral sensitization and hypersensitivity to hazelnut allergens in BALB/c mice and humans.
abstract: BACKGROUND
  Hazelnut allergy can be a consequence of sensitization to cross-reactive pollen, especially from the Fagales family. However, severe allergic reactions after ingestion of hazelnuts without associated pollen allergy have been reported. In these cases, oral sensitization by hazelnut ingestion is plausible.
  
  
  OBJECTIVE
  We have reported that antiulcer drugs promote oral sensitization to digestion-labile food allergens. Because hazelnut proteins were sensitive to gastric digestion in our in vitro assay, we aimed to analyze the effect of antiulcer treatment on oral sensitization to hazelnut proteins.
  
  
  METHODS
  BALB/c mice were fed hazelnut extract with or without antiulcer drugs. In parallel, gastroenterologic patients (n = 153) were screened during antiulcer treatment for specific immunoglobulin (Ig) E to hazelnut and inhalative allergens in vitro and in vivo.
  
  
  RESULTS
  Mice fed hazelnut extract in combination with antiulcer drugs formed anaphylactogenic IgG1 toward hazelnut and developed type I skin reactivity to hazelnut extract. In the human study population, 5 of 153 (3.3%) patients developed hazelnut-specific IgE, 4 of 5 developed specific skin reactivity, 3 of 5 had a positive result to oral provocation, and 2 of 5 manifested a food allergy to hazelnut after a 3-mo course of antiulcer treatment. Immunoblot testing with recombinant allergens showed that hazelnut, but not Fagales pollen, was the genuine elicitor in mice and humans.
  
  
  CONCLUSIONS
  Our experimental and epidemiologic data suggest that the intake of antiulcer drugs may lead to the induction of immediate-type food hypersensitivity toward hazelnut.
authors.affiliation: Department of Pathophysiology, Medical University of Vienna, Vienna, Austria.
authors.forename: Isabella
authors.initials: I
authors.lastname: Schöll
authors.forename: Eva
authors.initials: E
authors.lastname: Untersmayr
authors.forename: Noémi
authors.initials: N
authors.lastname: Bakos
authors.forename: Franziska
authors.initials: F
authors.lastname: Roth-Walter
authors.forename: Andreas
authors.initials: A
authors.lastname: Gleiss
authors.forename: George
authors.initials: G
authors.lastname: Boltz-Nitulescu
authors.forename: Otto
authors.initials: O
authors.lastname: Scheiner
authors.forename: Erika
authors.initials: E
authors.lastname: Jensen-Jarolim
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D000897:Anti-Ulcer Agents / Q000009:adverse effects*; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007114:Immunization; D007073:Immunoglobulin E / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008875:Middle Aged; D021184:Nut Hypersensitivity / Q000209:etiology* / Q000276:immunology / Q000503:physiopathology
chemical_list: D000897:Anti-Ulcer Agents; D007073:Immunoglobulin E