title: Diagnostic value of the serum-specific IgE ratio of ω-5 gliadin to wheat in adult patients with wheat-induced anaphylaxis.
abstract: BACKGROUND
  Wheat is an important food allergen associated with severe allergic reactions, including wheat-dependent exercise-induced anaphylaxis (WDEIA) and wheat-induced anaphylaxis (WIA). To diagnose WDEIA, an exercise challenge test following wheat ingestion is performed, which is time-consuming and unsafe. The compound ω-5 gliadin has been identified as a major allergen for WDEIA and WIA. We evaluated the diagnostic value of serum immunoglobulin E (IgE) ratios of ω-5 gliadin to wheat in adult patients with WDEIA or WIA.
  
  
  METHODS
  In total, 27 patients were enrolled and classified into 2 groups according to the severity of their allergic reactions to wheat. Serum IgE, specific to wheat and ω-5 gliadin, was measured using the ImmunoCAP system. To evaluate the diagnostic value, receiver operator characteristic curves were produced.
  
  
  RESULTS
  Group 1 included 17 patients with a history of anaphylaxis and group 2 included 10 patients having urticaria or atopic dermatitis. Serum IgE specific to wheat was increased in 47% of group 1 and 100% of group 2. However, all patients in group 1 had high serum IgE specific to ω-5 gliadin, whereas only 20% of group 2 showed increased levels. To identify a better diagnostic value, the log-transformed IgE ratio of ω-5 gliadin to wheat was calculated, with the cutoff value at 0.3. Based on these criteria, we found 100% sensitivity and specificity.
  
  
  CONCLUSIONS
  This study confirms that the serum IgE ratio of ω-5 gliadin to wheat may be a useful marker for the diagnosis of WDEIA and WIA.
authors: Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea.
authors: Han-Jung
authors: HJ
authors: Park
authors: Joo-Hee
authors: JH
authors: Kim
authors: Jeong-Eun
authors: JE
authors: Kim
authors: Hyun-Jung
authors: HJ
authors: Jin
authors: Gil-Soon
authors: GS
authors: Choi
authors: Young-Min
authors: YM
authors: Ye
authors: Hae-Sim
authors: HS
authors: Park
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology*; D000707:Anaphylaxis / Q000175:diagnosis* / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology*; D052179:Antigens, Plant; D005260:Female; D005903:Gliadin / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D014908:Triticum / Q000276:immunology*; D021182:Wheat Hypersensitivity / Q000175:diagnosis* / Q000276:immunology; D055815:Young Adult
chemical_list: D000485:Allergens; D052179:Antigens, Plant; C475180:omega-5 gliadin, wheat; D007073:Immunoglobulin E; D005903:Gliadin