title: A novel immunoassay using recombinant allergens simplifies peanut allergy diagnosis.
abstract: BACKGROUND
  Double-blind placebo-controlled food challenge (DBPCFC) is currently considered the gold standard for peanut allergy diagnosis. However, this procedure that requires the hospitalization of patients, mostly children, in specialized centers for oral exposure to allergens may cause severe reactions requiring emergency measures. Thus, a simpler and safer diagnosis procedure is needed. The aim of this study was to evaluate the diagnostic performance of a new set of in vitro blood tests for peanut allergy.
  
  
  METHODS
  The levels of IgE directed towards peanut extract and recombinant peanut allergens Ara h 1, Ara h 2, Ara h 3, Ara h 6, Ara h 7, and Ara h 8 were measured in 3 groups of patients enrolled at 2 independent centers: patients with proven peanut allergy (n=166); pollen-sensitized subjects without peanut allergy (n=61), and control subjects without allergic disease (n=10).
  
  
  RESULTS
  Seventy-nine percent of the pollen-sensitized patients showed IgE binding to peanut, despite their tolerance to peanut. In contrast, combining the results of specific IgE to peanut extract and to recombinant Ara h 2 and Ara h 6 yielded a peanut allergy diagnosis with a 98% sensitivity and an 85% specificity at a positivity threshold of 0.10 kU/l. Use of a threshold of 0.23 kU/l for recombinant Ara h 2 increased specificity (96%) at the cost of sensitivity (93%).
  
  
  CONCLUSIONS
  A simple blood test can be used to diagnose peanut allergy with a high level of precision. However, DBPCFC will remain useful for the few cases where immunological and clinical observations yield conflicting results.
authors.affiliation: EA3999 Maladies allergiques: diagnostic et thérapeutique, Department of Internal Medicine, Clinical Immunology and Allergology, University Hospital, Nancy, France.
authors.forename: F
authors.initials: F
authors.lastname: Codreanu
authors.forename: O
authors.initials: O
authors.lastname: Collignon
authors.forename: O
authors.initials: O
authors.lastname: Roitel
authors.forename: B
authors.initials: B
authors.lastname: Thouvenot
authors.forename: C
authors.initials: C
authors.lastname: Sauvage
authors.forename: A-C
authors.initials: AC
authors.lastname: Vilain
authors.forename: M-O
authors.initials: MO
authors.lastname: Cousin
authors.forename: A
authors.initials: A
authors.lastname: Decoster
authors.forename: J-M
authors.initials: JM
authors.lastname: Renaudin
authors.forename: C
authors.initials: C
authors.lastname: Astier
authors.forename: J-M
authors.initials: JM
authors.lastname: Monnez
authors.forename: P
authors.initials: P
authors.lastname: Vallois
authors.forename: M
authors.initials: M
authors.lastname: Morisset
authors.forename: D-A
authors.initials: DA
authors.lastname: Moneret-Vautrin
authors.forename: M
authors.initials: M
authors.lastname: Brulliard
authors.forename: V
authors.initials: V
authors.lastname: Ogier
authors.forename: M-C
authors.initials: MC
authors.lastname: Castelain
authors.forename: G
authors.initials: G
authors.lastname: Kanny
authors.forename: B E
authors.initials: BE
authors.lastname: Bihain
authors.forename: S
authors.initials: S
authors.lastname: Jacquenet
mesh_terms: D055516:2S Albumins, Plant / Q000235:genetics / Q000276:immunology*; D000293:Adolescent; D052179:Antigens, Plant / Q000235:genetics / Q000276:immunology*; D010367:Arachis / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D004311:Double-Blind Method; D005260:Female; D006023:Glycoproteins / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007073:Immunoglobulin E / Q000097:blood; D007223:Infant; D008297:Male; D021183:Peanut Hypersensitivity / Q000175:diagnosis* / Q000276:immunology; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D012680:Sensitivity and Specificity
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; D011994:Recombinant Proteins; D007073:Immunoglobulin E