title: sIgE Ana o 1, 2 and 3 accurately distinguish tolerant from allergic children sensitized to cashew nuts.
abstract: The double-blind, placebo-controlled food challenge test (DBPCFC) is the gold standard in cashew nut allergy. This test is costly, time consuming and not without side effects. Analysis of IgE reactivity to cashew nut components may reduce the need for food challenge tests.
  
  
  
  In a prospective and multicentre study, children with suspected cashew nut allergy underwent a DBPCFC with cashew nut. Specific IgE to cashew nut and to the components Ana o 1, 2 and 3 were determined. A skin prick test (SPT) with cashew nut extract was performed. The association between the outcome of the food challenge test and specific IgE to Ana o 1, 2 and 3 was assessed with logistic regression analyses, unadjusted and adjusted for other diagnostic variables. Discriminative ability was quantified with a concordance index (c).
  
  
  
  A total of 173 children (103 boys, 60%) with a median age of 9 years were included. About 79% had a positive challenge test outcome. A steep rise in the risk of a positive challenge was observed for specific IgE to each individual component Ana o 1, 2 and 3 with estimated risks up to approximately 100%. Median values of Ana o 1, 2, 3 were 1.29 kU/l (range 0-100 kU/l), 4.77 kU/l (range 0-100 kU/l) and 8.33 kU/l (range 0-100 kU/l) respectively and varied significantly (p < 0.001). Specific IgE to Ana o 1, 2 and 3 was better distinguished between cashew-allergic and tolerant children (c = 0.87, 0.85 and 0.89, respectively) than specific IgE to cashew nut or SPT (c = 0.76 and 0.83, respectively).
  
  
  
  The major cashew nut allergens Ana o 1, 2 and 3 are each individually predictive for the outcome of food challenge tests in cashew-allergic children.
authors: Department of Internal Medicine, Allergology, Erasmus MC, Rotterdam, The Netherlands.
authors: J P M
authors: JP
authors: van der Valk
authors: Department of Internal Medicine, Allergology, Erasmus MC, Rotterdam, The Netherlands.
authors: R
authors: R
authors: Gerth van Wijk
authors: Center for Medical Decision Making, Department of Public Health, Erasmus MC, Rotterdam, The Netherlands.
authors: Y
authors: Y
authors: Vergouwe
authors: Center for Medical Decision Making, Department of Public Health, Erasmus MC, Rotterdam, The Netherlands.
authors: E W
authors: EW
authors: Steyerberg
authors: Wageningen UR Food & Biobased Research, Wageningen, The Netherlands.
authors: M
authors: M
authors: Reitsma
authors: Wageningen UR Food & Biobased Research, Wageningen, The Netherlands.
authors: H J
authors: HJ
authors: Wichers
authors: Laboratory of Cell Biology and Immunology, Wageningen University, Wageningen, The Netherlands.
authors: H F J
authors: HF
authors: Savelkoul
authors: Department of Paediatrics, Onze Lieve Vrouwe Gasthuis (OLVG), Amsterdam, The Netherlands.
authors: B
authors: B
authors: Vlieg-Boerstra
authors: Department of Pediatric Allergology, Diaconessenhuis Voorburg, RdGG, Delft, The Netherlands.
authors: H
authors: H
authors: de Groot
authors: Department of Pediatric Pulmonology and Pediatric Allergology, University Medical Centre Groningen, GRIAC Research Institute, University of Groningen, Groningen, The Netherlands.
authors: A E J
authors: AE
authors: Dubois
authors: Department of Internal Medicine, Allergology, Erasmus MC, Rotterdam, The Netherlands.
authors: N W
authors: NW
authors: de Jong
mesh_terms: D000485:Allergens / Q000276:immunology*; D031021:Anacardium / Q000009:adverse effects*; D052179:Antigens, Plant / Q000276:immunology; D015415:Biomarkers; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology*; D008297:Male; D021184:Nut Hypersensitivity / Q000175:diagnosis* / Q000276:immunology*; D009754:Nuts / Q000009:adverse effects*; D010940:Plant Proteins / Q000276:immunology; D011446:Prospective Studies; D012882:Skin Tests
chemical_list: D000485:Allergens; C464614:Ana o 1 protein, Anacardium occidental; C478880:Ana o 2 allergen, cashew; C502483:Ana o 3 protein, Anacardium occidentale; D052179:Antigens, Plant; D015415:Biomarkers; D010940:Plant Proteins; D007073:Immunoglobulin E
keywords: Ana o 2 and Ana o 3; cashew nut allergy; children; component-resolved diagnosis; components Ana o 1; food challenge test