title: The diagnostic accuracy of specific IgE to Ara h 6 in adults is as good as Ara h 2.
abstract: Specific IgE (sIgE) to Ara h 2 is useful in diagnosing peanut allergy. Our aim was to assess the diagnostic value of sIgE to Ara h 6, another 2S albumin, in an adult population suspected of peanut allergy. Subjects with suspected peanut allergy between 2002 and 2013 were included if a diagnostic double-blind, placebo-controlled food challenge with peanut was performed. sIgE to Ara h 2 and Ara h 6 was measured by ImmunoCAP ISAC 112. Of 107 challenged subjects, 65 had a positive challenge (61%). The discriminative ability of sIgE to Ara h 2 and Ara h 6 was comparable: AUC 0.81 vs. 0.82. Positive predictive value for both tests was 95% using a cutoff value ≥1 ISU/l with poor corresponding sensitivity values (58% for Ara h 2, 62% for Ara h 6), but good specificity values (95% for both tests). In conclusion, the diagnostic value of sIgE to Ara h 6 on population level was as good as sIgE to Ara h 2. On individual level, however, 5% of the subjects showed contradicting results between both tests using a cutoff of 0.3 ISU/l, leading to a risk of misdiagnosis if only one of both tests is used.
authors.affiliation: Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: R J B
authors.initials: RJ
authors.lastname: Klemans
authors.forename: E F
authors.initials: EF
authors.lastname: Knol
authors.forename: C A F M
authors.initials: CA
authors.lastname: Bruijnzeel-Koomen
authors.forename: A C
authors.initials: AC
authors.lastname: Knulst
mesh_terms: D055516:2S Albumins, Plant / Q000276:immunology*; D000328:Adult; D052179:Antigens, Plant / Q000276:immunology*; D019540:Area Under Curve; D005260:Female; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D008297:Male; D021183:Peanut Hypersensitivity / Q000175:diagnosis* / Q000276:immunology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D055516:2S Albumins, Plant; D052179:Antigens, Plant; C500890:Ara h 2 allergen, Arachis hypogaea; C492737:Ara h 6 allergen, Arachis hypogaea; D006023:Glycoproteins; D007073:Immunoglobulin E
keywords: Ara h 2; Ara h 6; peanut allergy; peanut components; specific IgE