title: IgE sensitization to lupine in bakers - cross-reactivity or co-sensitization to wheat flour?
abstract: BACKGROUND
  Food allergy to lupine has frequently been reported in patients allergic to peanut or soy, and cross-reactivity between these legumes is known. Moreover, respiratory allergy to lupine has been described after inhalation, mostly at workplaces. Our aim was to study the frequency of lupine sensitization in European bakers with suspected bakers' allergy. Furthermore, associations between sensitizations to lupine and other plant allergens were investigated.
  
  
  METHODS
  One hundred and sixteen bakers with work-related allergic symptoms but without known food allergies were examined. Specific IgE (sIgE) antibodies to wheat flour, rye flour, lupine, peanut, soy and the recombinant single birch protein rBet v 1 were quantified. Selected sera were tested for cross-reactivity using ImmunoCAP inhibition and ISAC microarrays.
  
  
  RESULTS
  Whereas 67% of bakers were sensitized to wheat and/or rye flour, 35% showed sIgE to peanut and 33% to lupine. All lupine-positive bakers also had sIgE to either wheat flour (89%) and/or peanut (92%), and lupine sIgE correlated significantly with sIgE to peanut, soy, wheat and rye flour. Used as an inhibitor, wheat flour inhibited IgE binding to lupine in 4 out of 8 sera, indicating cross-reactivity. In microarrays, these sera showed IgE binding to lipid transfer proteins, profilins and/or cross-reactive carbohydrate determinants. Further inhibition experiments suggest that these single allergens are involved in cross-reactivity.
  
  
  CONCLUSIONS
  One third of 116 symptomatic bakers showed sIgE to lupine. At least some of these sensitizations were based on cross-reactivity between lupine and wheat flour. However, the considerable sensitization rate could also be a sign that the use of lupine flour in bakeries may be of occupational relevance.
authors.affiliation: Institute for Prevention and Occupational Medicine, German Social Accident Insurance, Ruhr University Bochum, Bochum, Germany.
authors.forename: Vera
authors.initials: V
authors.lastname: van Kampen
authors.forename: Ingrid
authors.initials: I
authors.lastname: Sander
authors.forename: Santiago
authors.initials: S
authors.lastname: Quirce
authors.forename: Thomas
authors.initials: T
authors.lastname: Brüning
authors.forename: Rolf
authors.initials: R
authors.lastname: Merget
authors.forename: Monika
authors.initials: M
authors.lastname: Raulf
mesh_terms: D000328:Adult; D052179:Antigens, Plant / Q000235:genetics / Q000276:immunology; D010367:Arachis / Q000737:chemistry / Q000276:immunology; D002352:Carrier Proteins / Q000235:genetics / Q000276:immunology; D005060:Europe; D005260:Female; D005433:Flour / Q000032:analysis*; D015870:Gene Expression / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood*; D031297:Lupinus / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000276:immunology*; D010940:Plant Proteins / Q000235:genetics / Q000276:immunology; D051304:Profilins / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D012130:Respiratory Hypersensitivity / Q000150:complications / Q000235:genetics / Q000276:immunology* / Q000503:physiopathology; D012189:Retrospective Studies; D013025:Glycine max / Q000737:chemistry / Q000276:immunology; D014908:Triticum / Q000737:chemistry / Q000276:immunology; D021182:Wheat Hypersensitivity / Q000150:complications / Q000235:genetics / Q000276:immunology* / Q000503:physiopathology
chemical_list: D052179:Antigens, Plant; D002352:Carrier Proteins; D010940:Plant Proteins; D051304:Profilins; D011994:Recombinant Proteins; C511920:lipid transfer proteins, plant; C539117:rBet v 1a Mut1-6 allergen, birch; D007073:Immunoglobulin E