title: Immunological Characterization of Dutch Sesame Seed-Allergic Patients.
abstract: BACKGROUND
  Sesame seed is an allergen of growing importance worldwide. However, knowledge of the clinically relevant sesame allergen and its cross-reactivity with homologous allergens is limited. The aim of this study was the immunological characterization of Dutch sesame seed-allergic patients and evaluation of cross-reactivity between sesame seed, tree nut and pollen allergens using different sources of allergen extracts.
  
  
  METHODS
  Six patients with a medical history of sesame seed allergy were included, i.e. 5 with an anaphylactic reaction and 1 with an oral allergy syndrome (OAS). The immunological background of the sesame seed and tree nut IgE sensitization was characterized with Western blotting and a basophil activation test (BAT). The major sesame allergen was identified by nanoLC-MS/MS. Cross-reactivity was measured using an immuno-inhibition assay with the Phadia ImmunoCAP system.
  
  
  RESULTS
  Oleosin was identified as the major allergen for the 5 patients with an anaphylactic reaction to sesame seed, but no cross-reactivity between sesame and tree nut proteins was observed. For the patient with OAS, IgE specific to oleosin was not detected but cross-reactivity between sesame seed and tree nut proteins was observed. The BAT and ImmunoCAP inhibition test added value to the clinical and immunological characterization of sesame seed-sensitized patients, distinguishing relevant and non-relevant sensitizations.
  
  
  CONCLUSIONS
  Our immunological approach enabled us to fully characterize the sensitization pattern of 6 sesame seed-allergic patients. The different protein composition of commercially available allergen extracts influences the outcomes of the immunological assays and thus also the diagnosis to a large extent.
authors.affiliation: Department of Cell Biology and Immunology, Wageningen University, Wageningen, The Netherlands.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Teodorowicz
authors.forename: Rozine J
authors.initials: RJ
authors.lastname: Terlouw
authors.forename: Ad
authors.initials: A
authors.lastname: Jansen
authors.forename: Huub F J
authors.initials: HF
authors.lastname: Savelkoul
authors.forename: Janneke
authors.initials: J
authors.lastname: Ruinemans-Koerts
mesh_terms: D000328:Adult; D001491:Basophils / Q000502:physiology; D003429:Cross Reactions; D005260:Female; D005512:Food Hypersensitivity / Q000209:etiology*; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010936:Plant Extracts / Q000276:immunology; D010940:Plant Proteins / Q000276:immunology; D012639:Seeds / Q000276:immunology; D031685:Sesamum / Q000276:immunology*
chemical_list: D010936:Plant Extracts; D010940:Plant Proteins; C110161:oleosin protein, Sesamum indicum; D007073:Immunoglobulin E