title: Ara h 2 is the best predictor for peanut allergy in adults.
abstract: BACKGROUND
  Specific IgE (sIgE) to Ara h 2 as a clinical predictor for peanut allergy in children has a diagnostic value comparable with a prediction model that contains sex, skin prick test (SPT), sIgE to peanut extract, and total IgE minus sIgE. In adults, the diagnostic value of peanut components has not yet been studied.
  
  
  OBJECTIVE
  To validate a pediatric prediction model in an adult population; to define the diagnostic value of sIgE to peanut components.
  
  
  METHODS
  Validation was performed by discrimination with an area under the receiver operating characteristic curve (AUC) and calibration with the Hosmer-Lemeshow test. The diagnostic value of the peanut components was assessed with the AUC.
  
  
  RESULTS
  Validation of the pediatric model in 94 adults showed poor discrimination (AUC, 0.64) but good calibration (P = .48); sIgE to Ara h 2 was the best diagnostic predictor (AUC, 0.76). By using a cutoff value with a 100% positive predictive value (≥1.75 kU/L), 28% of patients could be diagnosed with 100% accuracy. The highest negative predictive value was 63%. A higher negative predictive value could not be calculated for any other test. Although sIgE to Ara h 2 was significantly correlated with severity, it did not discriminate between mild and severe allergy in individual patients (AUC < 0.65).
  
  
  CONCLUSIONS
  sIgE to Ara h 2 has the best discriminative ability of all diagnostic tests. It can accurately diagnose peanut allergy in 28% of patients but cannot be used to exclude a peanut allergy in an adult population.
authors.affiliation: Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht, The Netherlands. Electronic address: r.j.b.klemans-3@umcutrecht.nl.
authors.forename: Rob J B
authors.initials: RJ
authors.lastname: Klemans
authors.affiliation: Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Henrike C H P
authors.initials: HC
authors.lastname: Broekman
authors.affiliation: Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht, The Netherlands; Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Edward F
authors.initials: EF
authors.lastname: Knol
authors.affiliation: Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Carla A F M
authors.initials: CA
authors.lastname: Bruijnzeel-Koomen
authors.affiliation: Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Henny G
authors.initials: HG
authors.lastname: Otten
authors.affiliation: Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht, The Netherlands; Center for Paediatric Allergology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands; Department of Pediatric Dermatology, Children's Hospital Erasmus University Medical Center-Sophia, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Suzanne G M A
authors.initials: SG
authors.lastname: Pasmans
authors.affiliation: Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: André C
authors.initials: AC
authors.lastname: Knulst
mesh_terms: D055516:2S Albumins, Plant / Q000032:analysis*; D000328:Adult; D000704:Analysis of Variance; D052179:Antigens, Plant / Q000032:analysis*; D005260:Female; D006023:Glycoproteins / Q000032:analysis*; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis; D008297:Male; D021183:Peanut Hypersensitivity / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D012882:Skin Tests / Q000379:methods
chemical_list: D055516:2S Albumins, Plant; D052179:Antigens, Plant; C500890:Ara h 2 allergen, Arachis hypogaea; D006023:Glycoproteins; D007073:Immunoglobulin E
keywords: Adults; Ara h 2; Diagnostic prediction model; Food challenge; Peanut allergy; Peanut components; Severity; Skin prick test; Specific IgE; Validation