title: IgE, IgG4 and IgA specific to Bet v 1-related food allergens do not predict oral allergy syndrome.
abstract: BACKGROUND
  Birch pollen-associated plant food allergy is caused by Bet v 1-specific IgE, but presence of cross-reactive IgE to related allergens does not predict food allergy. The role of other immunoglobulin isotypes in the birch pollen-plant food syndrome has not been investigated in detail.
  
  
  METHODS
  Bet v 1-sensitized birch pollen-allergic patients (n = 35) were diagnosed for food allergy by standardized interviews, skin prick tests, prick-to-prick tests and ImmunoCAP. Concentrations of allergen-specific IgE, IgG1, IgG4 and IgA to seven Bet v 1-related food allergens were determined by ELISA.
  
  
  RESULTS
  Bet v 1, Cor a 1, Mal d 1 and Pru p 1 bound IgE from all and IgG4 and IgA from the majority of sera. Immunoglobulins to Gly m 4, Vig r 1 and Api g 1.01 were detected in <65% of the sera. No significant correlation was observed between plant food allergy and increased or reduced levels of IgE, IgG1, IgG4 or IgA specific to most Bet v 1-related allergens. Api g 1-specific IgE was significantly (P = 0.01) elevated in celeriac-allergic compared with celeriac-tolerant patients. Likewise, frequencies of IgE (71% vs 15%; P = 0.01) and IgA (86% vs 38%; P = 0.04) binding to Api g 1.01 were increased.
  
  
  CONCLUSIONS
  Measurements of allergen-specific immunoglobulins are not suitable for diagnosing Bet v 1-mediated plant food allergy to hazelnut and Rosaceae fruits. In contrast, IgE and IgA to the distantly related allergen Api g 1 correlate with allergy to celeriac.
authors.affiliation: Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.
authors.forename: E E
authors.initials: EE
authors.lastname: Guhsl
authors.forename: G
authors.initials: G
authors.lastname: Hofstetter
authors.forename: N
authors.initials: N
authors.lastname: Lengger
authors.forename: W
authors.initials: W
authors.lastname: Hemmer
authors.forename: C
authors.initials: C
authors.lastname: Ebner
authors.forename: R
authors.initials: R
authors.lastname: Fröschl
authors.forename: M
authors.initials: M
authors.lastname: Bublin
authors.forename: C
authors.initials: C
authors.lastname: Lupinek
authors.forename: H
authors.initials: H
authors.lastname: Breiteneder
authors.forename: C
authors.initials: C
authors.lastname: Radauer
mesh_terms: D000918:Antibody Specificity / Q000276:immunology*; D052179:Antigens, Plant / Q000276:immunology*; D015549:Basophil Degranulation Test; D001491:Basophils / Q000276:immunology; D003429:Cross Reactions / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005512:Food Hypersensitivity / Q000175:diagnosis* / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology*; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D010940:Plant Proteins / Q000276:immunology; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012882:Skin Tests
chemical_list: D052179:Antigens, Plant; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D010940:Plant Proteins; C061312:Bet v 1 allergen, Betula; D007073:Immunoglobulin E
keywords: Bet v 1; IgA; IgE; IgG; food allergy