title: Immunoglobulin E recognition patterns to purified Kiwifruit (Actinidinia deliciosa) allergens in patients sensitized to Kiwi with different clinical symptoms.
abstract: BACKGROUND
  Green kiwifruit allergy is on the rise. However, no surveys testing purified major kiwi allergens have been carried out in a large population, including both kiwi-sensitized [skin prick test (SPT)-positive] and truly kiwi-allergic patients.
  
  
  OBJECTIVE
  To isolate major kiwifruit allergens, and to explore their relevance by in vitro and in vivo methods in a large kiwi-sensitized and -allergic population.
  
  
  METHODS
  A large group (n=92) of kiwi-sensitized patients with different clinical symptoms were selected, and double-blind, placebo-controlled, food challenges to kiwi were performed in 52 of them. The three major IgE-binding proteins from kiwifruit extracts were isolated and characterized by N-terminal amino acid sequencing and molecular size and glycosylation analysis. The allergenic potency of the three kiwi allergens, and of avocado Pers a 1 as a model allergen associated with the latex-fruit syndrome, was tested by specific IgE quantitation, immunodetection assays and SPTs.
  
  
  RESULTS
  The isolated kiwifruit allergens were identified as actinidin Act d 1, glycosylated thaumatin-like Act d 2 and a novel 40 kDa glycoprotein designated as Act d 3.02. Specific IgE to each of the three allergens was found in over 60% of sera from kiwi-sensitized patients, and Act d 1 and Act d 2 induced positive SPT responses in over 50% of the tested patients. A significant link between IgE levels to Act d 1 and Act d 3 and anaphylaxis was uncovered. Avocado Pers a 1 showed an in vitro sensitization prevalence of around 45%, but a low in vivo reactivity.
  
  
  CONCLUSIONS
  Act d 1, Act d 2 and Act d 3 are major allergens in the population studied. Severe symptoms after kiwi ingestion are associated with high IgE levels to Act d 1 and Act d 3.
authors.affiliation: Departamento de Biotecnología, Unidad de Bioquimica, ETS Ingenieros Agronomos, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Palacin
authors.forename: J
authors.initials: J
authors.lastname: Rodriguez
authors.forename: C
authors.initials: C
authors.lastname: Blanco
authors.forename: G
authors.initials: G
authors.lastname: Lopez-Torrejon
authors.forename: R
authors.initials: R
authors.lastname: Sánchez-Monge
authors.forename: J
authors.initials: J
authors.lastname: Varela
authors.forename: M A
authors.initials: MA
authors.lastname: Jiménez
authors.forename: J
authors.initials: J
authors.lastname: Cumplido
authors.forename: T
authors.initials: T
authors.lastname: Carrillo
authors.forename: J F
authors.initials: JF
authors.lastname: Crespo
authors.forename: G
authors.initials: G
authors.lastname: Salcedo
mesh_terms: D029042:Actinidia / Q000276:immunology*; D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology* / Q000302:isolation & purification; D000707:Anaphylaxis / Q000276:immunology; D002648:Child; D002688:Chitinases / Q000276:immunology / Q000302:isolation & purification; D003546:Cysteine Endopeptidases / Q000276:immunology / Q000302:isolation & purification; D004311:Double-Blind Method; D005260:Female; D005512:Food Hypersensitivity / Q000175:diagnosis / Q000276:immunology*; D005638:Fruit / Q000276:immunology*; D006023:Glycoproteins / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010940:Plant Proteins / Q000276:immunology / Q000302:isolation & purification; D012882:Skin Tests
chemical_list: D000485:Allergens; D006023:Glycoproteins; D010940:Plant Proteins; D007073:Immunoglobulin E; D002688:Chitinases; D003546:Cysteine Endopeptidases; C018745:actinidain