title: Component-resolved diagnosis of baker's allergy based on specific IgE to recombinant wheat flour proteins.
abstract: BACKGROUND
  Sensitization to wheat flour plays an important role in the development and diagnosis of baker's asthma.
  
  
  OBJECTIVE
  We evaluated wheat allergen components as sensitizers for bakers with work-related complaints, with consideration of cross-reactivity to grass pollen.
  
  
  METHODS
  Nineteen recombinant wheat flour proteins and 2 cross-reactive carbohydrate determinants were tested by using CAP-FEIA in sera of 101 bakers with wheat flour allergy (40 German, 37 Dutch, and 24 Spanish) and 29 pollen-sensitized control subjects with wheat-specific IgE but without occupational exposure. IgE binding to the single components was inhibited with wheat flour, rye flour, and grass pollen. The diagnostic efficiencies of IgE tests with single allergens and combinations were evaluated by assessing their ability to discriminate between patients with baker's allergy and control subjects based on receiver operating characteristic analyses.
  
  
  RESULTS
  Eighty percent of bakers had specific IgE levels of 0.35 kUA/L or greater and 91% had specific IgE levels of 0.1 kUA/L or greater to at least one of the 21 allergens. The highest frequencies of IgE binding were found for thiol reductase (Tri a 27) and the wheat dimeric α-amylase inhibitor 0.19 (Tri a 28). Cross-reactivity to grass pollen was proved for 9 components, and cross-reactivity to rye flour was proved for 18 components. A combination of IgE tests to 5 components, Tri a 27, Tri a 28, tetrameric α-amylase inhibitor CM2 (Tri a 29.02), serine protease inhibitor-like allergen (Tri a 39), and 1-cys-peroxiredoxin (Tri a 32), produced the maximal area under the curve (AUC = 0.84) in receiver operating characteristic analyses, but this was still lower than the AUC for wheat- or rye flour-specific IgE (AUC = 0.89 or 0.88, respectively).
  
  
  CONCLUSIONS
  Component-resolved diagnostics help to distinguish between sensitization caused by occupational flour exposure and wheat seropositivity based on cross-reactivity to grass pollen. For routine diagnosis of baker's allergy, however, allergen-specific IgE tests with whole wheat and rye flour extracts remain mandatory because of superior diagnostic sensitivity.
authors.affiliation: Institute for Prevention and Occupational Medicine, German Social Accident Insurance, Ruhr University Bochum (IPA), Bochum, Germany. Electronic address: Sander@ipa-dguv.de.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Sander
authors.affiliation: Institute for Prevention and Occupational Medicine, German Social Accident Insurance, Ruhr University Bochum (IPA), Bochum, Germany.
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Rihs
authors.affiliation: Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands.
authors.forename: Gert
authors.initials: G
authors.lastname: Doekes
authors.affiliation: Department of Allergy, Hospital La Paz Institute for Health Research (IdiPAZ) and CIBER of Respiratory Diseases (CIBERES), Madrid, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Quirce
authors.affiliation: Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, The Netherlands.
authors.forename: Esmeralda
authors.initials: E
authors.lastname: Krop
authors.affiliation: Institute for Prevention and Occupational Medicine, German Social Accident Insurance, Ruhr University Bochum (IPA), Bochum, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Rozynek
authors.affiliation: Institute for Prevention and Occupational Medicine, German Social Accident Insurance, Ruhr University Bochum (IPA), Bochum, Germany.
authors.forename: Vera
authors.initials: V
authors.lastname: van Kampen
authors.affiliation: Institute for Prevention and Occupational Medicine, German Social Accident Insurance, Ruhr University Bochum (IPA), Bochum, Germany.
authors.forename: Rolf
authors.initials: R
authors.lastname: Merget
authors.affiliation: Institute for Prevention and Occupational Medicine, German Social Accident Insurance, Ruhr University Bochum (IPA), Bochum, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Meurer
authors.affiliation: Institute for Prevention and Occupational Medicine, German Social Accident Insurance, Ruhr University Bochum (IPA), Bochum, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Brüning
authors.affiliation: Institute for Prevention and Occupational Medicine, German Social Accident Insurance, Ruhr University Bochum (IPA), Bochum, Germany.
authors.forename: Monika
authors.initials: M
authors.lastname: Raulf
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D052179:Antigens, Plant / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification; D019540:Area Under Curve; D059366:Asthma, Occupational / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D003429:Cross Reactions; D005260:Female; D005433:Flour / Q000032:analysis*; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D054464:Peroxiredoxins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification; D010940:Plant Proteins / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D006109:Poaceae / Q000737:chemistry / Q000276:immunology; D011058:Pollen / Q000737:chemistry / Q000276:immunology; D012372:ROC Curve; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification; D006255:Rhinitis, Allergic, Seasonal / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D021182:Wheat Hypersensitivity / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D010940:Plant Proteins; D011994:Recombinant Proteins; C539494:Tri a Bd 27K allergen, Triticum aestivum; C071392:CM protein, Triticum aestivum; D007073:Immunoglobulin E; D054464:Peroxiredoxins
keywords: Baker's asthma; Triticum aestivum; alpha-amylase inhibitor; component-resolved diagnosis; cross-reactivity; grass pollen; recombinant allergens; rye flour; specific IgE; wheat allergy