title: Cor a 14 is the superior serological marker for hazelnut allergy in children, independent of concomitant peanut allergy.
abstract: BACKGROUND
  Hazelnut is the most frequent cause of tree nut allergy, but up to half of all children with hazelnut allergy additionally suffer from peanut allergy. Our aim was to identify diagnostic values of the most promising serological markers (Cor a 9 and Cor a 14) and to address the influence of concomitant peanut allergy and PR10 sensitization.
  
  
  METHODS
  We included 155 children suspected of hazelnut allergy and challenged according to the guidelines. Concomitant allergy to peanuts was verified or ruled out by challenge. Skin prick test, s-IgE and CRD to hazelnut, peanut, PR10 and LPT protein families were measured using ImmunoCAP.
  
  
  RESULTS
  Sixty-five children had a positive hazelnut challenge, and 60% of these also had a concomitant peanut allergy. Children allergic to hazelnut were sensitized to Cor a 9 and Cor a 14; peanut-allergic children were sensitized to Ara h 2. Sensitization to PR10 protein components was seen in 45% of all included children, irrelevant to allergy to peanut or hazelnut. A cut-off >0.72 kU/L of IgE towards Cor a 14 diagnosed 87% correctly, making Cor a 14 the superior serology marker. However, nine hazelnut-allergic children were primarily sensitized to Cor a 9.
  
  
  CONCLUSIONS
  Concomitant peanut allergy is common in hazelnut-allergic children, but decision points as well as diagnostic values for Cor a 14 are not affected. We found three independent and well-characterized serotypes; hazelnut-allergic children were sensitized to Cor a 14, peanut-allergic children were sensitized to Ara h 2, and independently of this were children sensitized to birch pollen (Bet v 1).
authors.affiliation: Odense Research Center for Anaphylaxis (ORCA), Odense University Hospital, Odense, Denmark.|Department of Dermatology and Allergy Centre, Odense University Hospital, Odense, Denmark.
authors.forename: E
authors.initials: E
authors.lastname: Eller
authors.affiliation: Odense Research Center for Anaphylaxis (ORCA), Odense University Hospital, Odense, Denmark.|Department of Dermatology and Allergy Centre, Odense University Hospital, Odense, Denmark.
authors.forename: C G
authors.initials: CG
authors.lastname: Mortz
authors.affiliation: Odense Research Center for Anaphylaxis (ORCA), Odense University Hospital, Odense, Denmark.|Department of Dermatology and Allergy Centre, Odense University Hospital, Odense, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Bindslev-Jensen
mesh_terms: D000485:Allergens / Q000276:immunology*; D052179:Antigens, Plant / Q000276:immunology*; D015415:Biomarkers; D002648:Child; D002675:Child, Preschool; D031211:Corylus / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007114:Immunization; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D007223:Infant; D008297:Male; D021184:Nut Hypersensitivity / Q000097:blood* / Q000175:diagnosis / Q000276:immunology*; D021183:Peanut Hypersensitivity / Q000097:blood* / Q000276:immunology*; D012372:ROC Curve; D012189:Retrospective Studies; D012882:Skin Tests
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D015415:Biomarkers; C000594310:Cor a 14 allergen, hazelnut; D007073:Immunoglobulin E
keywords: Cor a 14; IgE; anaphylaxis; hazelnut allergy; paediatrics