title: Components in soy allergy diagnostics: Gly m 2S albumin has the best diagnostic value in adults.
abstract: BACKGROUND
  Thus far, four soy allergens have been characterized. Their diagnostic value was assessed only using a case-control design with controls not suspected of soy allergy or in a soy-allergic population without controls. Our objective was to analyze the diagnostic value of specific immunoglobulin E (sIgE) to Gly m 2S albumin, Gly m 4, 5, and 6, and their possible relation with severity or culprit soy product.
  
  
  METHODS
  Adult patients suspected of soy allergy were included (n = 46). Allergy was confirmed by challenge (n = 19) or history (n = 16) and excluded by challenge in 11 patients. Soy components were analyzed by ImmunoCAP. Diagnostic value was assessed in the challenged patient group by an area under receiver operating characteristic (ROC) curve (AUC).
  
  
  RESULTS
  Specific immunoglobulin E to Gly m 2S albumin had the highest AUC (0.79), comparable to skin prick test (SPT) and sIgE to soy extract (0.76 and 0.77, respectively). All patients were sensitized to either soy extract or Gly m 4 (sIgE ≥ 0.35 kU/l). sIgE to soy extract, Gly m 5, and Gly m 6 was significantly higher in patients with mild symptoms (P = 0.04, 0.02 and 0.02, respectively). Patients only reacting to soy milk had higher sIgE levels to Gly m 4 (median 9.8 vs 1.1 kU/l, P = 0.01).
  
  
  CONCLUSIONS
  Specific immunoglobulin E to Gly m 2S albumin had the best accuracy in diagnosing soy allergy. Gly m 5 and 6 were related to mild symptoms. Higher levels of Gly m 4 were related to allergy to soy milk.
authors.affiliation: Department of (Paediatric) 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: A
authors.initials: A
authors.lastname: Michelsen-Huisman
authors.forename: S G M A
authors.initials: SG
authors.lastname: Pasmans
authors.forename: W
authors.initials: W
authors.lastname: de Kruijf-Broekman
authors.forename: C A F M
authors.initials: CA
authors.lastname: Bruijnzeel-Koomen
authors.forename: E
authors.initials: E
authors.lastname: van Hoffen
authors.forename: A C
authors.initials: AC
authors.lastname: Knulst
mesh_terms: D000707:Anaphylaxis / Q000175:diagnosis / Q000276:immunology; D005260:Female; D005512:Food Hypersensitivity / Q000175:diagnosis* / Q000276:immunology* / Q000378:metabolism; D005998:Glycine / Q000737:chemistry; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D041942:Soy Milk / Q000737:chemistry; D030262:Soybean Proteins / Q000737:chemistry / Q000276:immunology*; D013025:Glycine max / Q000276:immunology*; D055815:Young Adult
chemical_list: C120514:GM2S-1 protein, soybean; D030262:Soybean Proteins; D007073:Immunoglobulin E; D005998:Glycine
keywords: Gly m 2S albumin; diagnostics; soy allergy; soy components; soy milk