title: Comparison of commercially available serologic kits for the detection of celiac disease.
abstract: BACKGROUND
  The sensitivity and specificity of current antihuman tissue transglutaminase (tTG) IgA assays used to detect celiac disease reportedly approach 100%. In addition, the sensitivity of new generation deamidated gliadin peptide (alpha-DGP) antibody assays has also been reported to be similar to the tTG IgA assays. In routine clinical practice, however, the sensitivities and specificities of these tests for diagnosing celiac disease seem to be lower.
  
  
  OBJECTIVE
  We analyzed sensitivities and specificities of 4 IgA tTG and 3 deamidated gliadin peptide (alpha-DGP) kits.
  
  
  METHODS
  The performance of 4 tTG IgA assays, A: Inova (Hu red blood cell), B: Binding site (rHu Ag), C: Eurospital (rHu Ag), D: Immco (rHu Ag) and 3 Inova alpha-DGP assays, E: alpha-DGP-IgA, F: alpha-DGP-IgG, and G: alpha-DGP-IgA+G was evaluated using sera from different subsets of celiac disease patients and controls; group 1: active celiac disease n=28, group 2: gluten-free diet n=54, group 3: healthy controls n=40, group 4: disease controls n=57(Crohn's disease n=17, chronic hepatitis n=40).
  
  
  RESULTS
  Using the manufacturer's cut-off values, the sensitivities and specificities of different kits ranged from 71.4% to 96.4% and 87.5% to 100%, respectively. When group 1 was compared with disease controls, sensitivities remained the same but specificities decreased. Receiver operating characteristic plot derived cut-off values modified decision thresholds in all assays except kit (G). Kappa analysis demonstrated variable degrees of agreement. All assays demonstrated higher sensitivities for patients with higher grades of villous atrophy.
  
  
  CONCLUSIONS
  Overall sensitivity was at or below 90%, which is lower than that reported in the literature. Performance of the recombinant and red blood cell antigen-based tTG assays was similar, whereas the alpha-DGP assays demonstrated lower values. Receiver operating characteristic plot derived cut-off values altered test results. Many factors affect the results of these tests and clinicians should be aware of their limitations.
authors: Department of Medicine and Pathology, Columbia University, New York, NY 10032, USA.
authors: Afzal J
authors: AJ
authors: Naiyer
authors: Lincoln
authors: L
authors: Hernandez
authors: Edward J
authors: EJ
authors: Ciaccio
authors: Konstantinos
authors: K
authors: Papadakis
authors: John S
authors: JS
authors: Manavalan
authors: Govind
authors: G
authors: Bhagat
authors: Peter H R
authors: PH
authors: Green
mesh_terms: D000328:Adult; D002446:Celiac Disease / Q000175:diagnosis* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005903:Gliadin / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D012372:ROC Curve; D011933:Reagent Kits, Diagnostic; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012698:Serologic Tests; D011503:Transglutaminases / Q000276:immunology*
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D011933:Reagent Kits, Diagnostic; D005903:Gliadin; D011503:Transglutaminases