title: Clinical value of component-resolved diagnostics in peanut-allergic patients.
abstract: BACKGROUND
  As replacement for the oral food challenge, decision-points for sensitization test have been established, but suboptimal sensitivity and/or specificity, as well as regional differences, have reduced the clinical usability. IgE toward specific peanut protein components has been reported to be of value, but data on correlation with clinical data are sparse. Our aim was to correlate IgE values with the outcome of peanut challenges.
  
  
  METHODS
  Data from 175 positive and 30 negative peanut challenges in patients aged 1-26 years were retrospectively correlated with the levels of specific IgE to peanut and peanut components (Ara h 1-3, h 8, and h 9).
  
  
  RESULTS
  The best correlation between IgE and clinical thresholds was found for Ara h 2 (ρ(s) = -0.30, P < 0.01). A cutoff of Ara h 2 > 1.63 kU/l yielded a specificity = 1.00, with a corresponding sensitivity of 0.70. Symptom severity elicited during challenge correlated significantly with the levels of Ara h 2 (ρ(s) = 0.60, P < 0.0001), but large individual variation was found.
  
  
  CONCLUSIONS
  The level of IgE toward Ara h 2 can improve diagnostic accuracy by introducing a more clear-cut decision-point with an optimal specificity maintaining a high sensitivity. In our study, this would have reduced the necessary number of challenges to be performed from 205 to 92. Extrapolation between centers is difficult and decision-points need to be addressed in relation to settings and population. Further component-resolved diagnostic cannot replace oral challenge neither in determining thresholds nor in the assessment of severity of symptoms elicited during challenge.
authors.affiliation: Department of Dermatology & Allergy Center, Odense University Hospital, Odense, Denmark. Esben.Eller@ouh.region
authors.forename: E
authors.initials: E
authors.lastname: Eller
authors.forename: C
authors.initials: C
authors.lastname: Bindslev-Jensen
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens; D052179:Antigens, Plant / Q000276:immunology; D010367:Arachis / Q000276:immunology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D007108:Immune Tolerance / Q000502:physiology*; D007114:Immunization; D007073:Immunoglobulin E / Q000276:immunology*; D007223:Infant; D008297:Male; D021183:Peanut Hypersensitivity / Q000175:diagnosis* / Q000276:immunology; D012016:Reference Values; D012189:Retrospective Studies; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D055815:Young Adult
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D007073:Immunoglobulin E