title: Diagnostic Value of Specific IgE to Peanut and Ara h 2 in Korean Children with Peanut Allergy.
abstract: OBJECTIVE
  The purpose of this study was to establish the diagnostic decision point (DDP) of peanut specific IgE (sIgE) for predicting the outcome of oral food challenge (OFC). We also evaluated the usefulness of sIgE to peanut components (Ara h 1, 2, 3, 8, and 9) in diagnosing peanut allergy.
  
  
  METHODS
  Korean children aged over 12 months with a suspected peanut allergy were enrolled. Diagnosis of peanut allergy was confirmed by an open OFC or through the convincing history of anaphylaxis. Cutoff levels of sIgE to peanut and peanut components were determined by analyzing receiver operating characteristic curves.
  
  
  RESULTS
  Forty-eight children (22 boys and 26 girls) with a suspected peanut allergy were enrolled. The previously established DDP for peanut-sIgE antibodies (14 kU/L) showed a sensitivity of 22.7%, specificity of 100%, positive predictive value (PPV) of 100%, and negative predictive value of 60.4% in our study population. The median levels of peanut-sIgE (5.4 kU/L vs 1.1 kU/L, P<0.001) and Ara h 2-sIgE (0.8 kU/L vs 0 kU/L, P<0.001) were significantly higher in the peanut allergy group than in the peanut tolerance group. The peanut-sIgE concentration indicating a PPV of 100% was 10.3 kU/L. The Ara h 2-sIgE level of 4.0 kU/L had a PPV of 100%.
  
  
  CONCLUSIONS
  Our results showed that the cutoff levels for peanut (10.3 kU/L) and Ara h 2 (4.0 kU/L) established in this study is useful for the diagnosis of peanut allergy in Korean children.
authors.affiliation: Department of Pediatrics, Medical Research Institute of Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Hye Young
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.|Environmental Health Center for Atopic Diseases, Samsung Medical Center, Seoul, Korea.
authors.forename: Youngshin
authors.initials: Y
authors.lastname: Han
authors.affiliation: Department of Pediatrics, Medical Research Institute of Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea.
authors.forename: Kwanghoon
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.|Environmental Health Center for Atopic Diseases, Samsung Medical Center, Seoul, Korea.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Biostatistics, Samsung Biomedical Research Institute, Seoul, Korea.
authors.forename: Min Ji
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.|Environmental Health Center for Atopic Diseases, Samsung Medical Center, Seoul, Korea.
authors.forename: Kangmo
authors.identifier: http://orcid.org/0000-0001-7751-9829
authors.initials: K
authors.lastname: Ahn
authors.affiliation: Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.|Environmental Health Center for Atopic Diseases, Samsung Medical Center, Seoul, Korea. jhlovechild@gmail.com.
authors.forename: Jihyun
authors.initials: J
authors.lastname: Kim
keywords: Food allergy; peanut allergy; specific IgE