title: Accuracy of serologic tests and HLA-DQ typing for diagnosing celiac disease.
abstract: BACKGROUND
  Estimates of the diagnostic performance of serologic testing and HLA-DQ typing for detecting celiac disease have mainly come from case-control studies.
  
  
  OBJECTIVE
  To define the performance of serologic testing and HLA-DQ typing prospectively.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Patients referred for small-bowel biopsy for the diagnosis of celiac disease.
  
  
  METHODS
  Celiac serologic testing (antigliadin antibodies [AGA], antitransglutaminase antibodies [TGA], and antiendomysium antibodies [EMA]) and HLA-DQ typing.
  
  
  METHODS
  Diagnostic performance of serologic testing and HLA-DQ typing compared with a reference standard of abnormal histologic findings and clinical resolution after a gluten-free diet.
  
  
  RESULTS
  Sixteen of 463 participants had celiac disease (prevalence, 3.46% [95% CI, 1.99% to 5.55%]). A positive result on both TGA and EMA testing had a sensitivity of 81% (CI, 54% to 95.9%), specificity of 99.3% (CI, 98.0% to 99.9%), and negative predictive value of 99.3% (CI, 98.0% to 99.9%). Testing positive for either HLA-DQ type maximized sensitivity (100% [CI, 79% to 100%]) and negative predictive value (100% [CI, 98.6% to 100%]), whereas testing negative for both minimized the negative likelihood ratio (0.00 [CI, 0.00 to 0.40]) and posttest probability (0% [CI, 0% to 1.4%]). The addition of HLA-DQ typing to TGA and EMA testing, and the addition of serologic testing to HLA-DQ typing, did not change test performance compared with either testing strategy alone.
  
  
  CONCLUSIONS
  Few cases of celiac disease precluded meaningful comparisons of testing strategies.
  
  
  CONCLUSIONS
  In a patient population referred for symptoms and signs of celiac disease with a prevalence of celiac disease of 3.46%, TGA and EMA testing were the most sensitive serum antibody tests and a negative HLA-DQ type excluded the diagnosis. However, the addition of HLA-DQ typing to TGA and EMA testing, and the addition of serologic testing to HLA-DQ typing, provided the same measures of test performance as either testing strategy alone.
authors.affiliation: Department of Gastroenterology, Het Groene Hart Ziekenhuis, Gouda, The Netherlands. muhammed.hadithi@ghz.nl
authors.forename: Muhammed
authors.initials: M
authors.lastname: Hadithi
authors.forename: B Mary E
authors.initials: BM
authors.lastname: von Blomberg
authors.forename: J Bart A
authors.initials: JB
authors.lastname: Crusius
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Bloemena
authors.forename: Pieter J
authors.initials: PJ
authors.lastname: Kostense
authors.forename: Jos W R
authors.initials: JW
authors.lastname: Meijer
authors.forename: Chris J J
authors.initials: CJ
authors.lastname: Mulder
authors.forename: Coen D A
authors.initials: CD
authors.lastname: Stehouwer
authors.forename: Amado S
authors.initials: AS
authors.lastname: Peña
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood; D001706:Biopsy; D002446:Celiac Disease / Q000175:diagnosis* / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D005838:Genotype; D005903:Gliadin / Q000276:immunology; D006026:Glycoside Hydrolases / Q000276:immunology; D006683:HLA-DQ Antigens / Q000235:genetics*; D006801:Humans; D007159:Immunologic Tests; D007421:Intestine, Small / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011503:Transglutaminases / Q000276:immunology