title: Characterization of the sensitization profile to lupin in peanut-allergic children and assessment of cross-reactivity risk.
abstract: BACKGROUND
  Case reports of allergy to lupin, due to primary sensitization or cross-reactions with other legumes, are increasing as a consequence of the augmented use of lupin flour in bakery, pasta formulations and other food items. The main allergens that have been associated with the sensitization to lupin are α- and β-conglutins and, to a lesser extent, γ- and δ-conglutin, but no conclusive data are available so far. The aim of this study was to characterize the sensitization pattern to lupin in a group of 12 Italian children allergic to peanut and identify the specific lupin proteins involved in the cross-reactivity with peanut.
  
  
  METHODS
  The immunochemical cross-reactivity among peanut and lupin was evaluated by both in vitro immunoblotting and in vivo fresh food skin prick test (FFSPT).
  
  
  RESULTS
  The results showed that β-conglutin was recognized by cutaneous IgEs from 7/12 peanut-allergic children in FFSPT and serum IgEs from 5/12 in immunoblotting, while 4/12 and 8/12 patients tested positive to γ-conglutin in FFSPT and immunoblotting, respectively. No significant immunoreactive responses were observed to α- and δ-conglutins under non-reducing conditions, but they were bound in FFSPT by the sera of 5/12 and 3/12 patients, respectively.
  
  
  CONCLUSIONS
  In this group of allergic children, β-conglutin has been identified as the major lupin allergen involved both in vitro and in vivo cross-reactivity with peanut proteins. The role of γ-conglutin in the cross-reactivity between lupin and peanut proteins was also relevant and clear, despite the observed unspecificity of the immunoblotting responses.
authors.affiliation: Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Ballabio
authors.forename: Elena
authors.initials: E
authors.lastname: Peñas
authors.forename: Francesca
authors.initials: F
authors.lastname: Uberti
authors.forename: Alessandro
authors.initials: A
authors.lastname: Fiocchi
authors.forename: Marcello
authors.initials: M
authors.lastname: Duranti
authors.forename: Chiara
authors.initials: C
authors.lastname: Magni
authors.forename: Patrizia
authors.initials: P
authors.lastname: Restani
mesh_terms: D000485:Allergens / Q000276:immunology*; D010367:Arachis / Q000009:adverse effects*; D002648:Child; D003429:Cross Reactions; D005260:Female; D006801:Humans; D007114:Immunization; D007073:Immunoglobulin E / Q000276:immunology; D007558:Italy; D031297:Lupinus / Q000009:adverse effects*; D008297:Male; D021184:Nut Hypersensitivity / Q000175:diagnosis / Q000276:immunology*; D011485:Protein Binding; D055314:Seed Storage Proteins / Q000276:immunology / Q000378:metabolism*; D012882:Skin Tests
chemical_list: D000485:Allergens; D055314:Seed Storage Proteins; C042457:conglutin protein, Lupinus angustifolius; D007073:Immunoglobulin E