title: A report on the International Transglutaminase Autoantibody Workshop for Celiac Disease.
abstract: OBJECTIVE
  Measurement of transglutaminase autoantibodies (TGAA) is considered to be the most efficient single serologic test for celiac disease (CD) by the American Gastroenterological Association Institute. We hypothesized that a large international collaborative effort toward improving and standardizing TGAA measurement is both feasible and necessary. The primary aim of this workshop is to compare TGAA assays among various research and clinical laboratories to examine assay concordance and improve (and eventually standardize) the TGAA assay.
  
  
  METHODS
  A total of 20 laboratories (5 commercial laboratories, 15 research and clinical laboratories) participated that included enzyme-linked immunosorbent assay (ELISA) and radiobinding assays. A total of 150 serum samples were distributed to each laboratory, with each laboratory receiving an equal aliquot that was coded and blinded, composed of 100 healthy control sera and 50 CD sera.
  
  
  RESULTS
  Laboratory sensitivity ranged from 69% to 93% and specificity ranged from 96% to 100%. By receiver operator characteristic analysis, the area under the curve (C index) ranged from 0.9488 to 0.9904. When analyzing for linear correlation, r-squared was as high as 0.8882 but as low as 0.4244 for the celiac samples between different laboratories performing ELISA.
  
  
  CONCLUSIONS
  This transglutaminase autoantibody workshop allows for larger-scale international participation for the purposes of improving and eventually standardizing the TGAA assay with subsequent workshops.
authors.affiliation: University of Colorado Denver, Anshultz Medical Campus, Aurora, CO 80010, USA.
authors.forename: Marcella
authors.initials: M
authors.lastname: Li
authors.forename: Liping
authors.initials: L
authors.lastname: Yu
authors.forename: Claudio
authors.initials: C
authors.lastname: Tiberti
authors.forename: Margherita
authors.initials: M
authors.lastname: Bonamico
authors.forename: Iman
authors.initials: I
authors.lastname: Taki
authors.forename: Dongmei
authors.initials: D
authors.lastname: Miao
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Murray
authors.forename: Marian J
authors.initials: MJ
authors.lastname: Rewers
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Hoffenberg
authors.forename: Daniel
authors.initials: D
authors.lastname: Agardh
authors.forename: Patricia
authors.initials: P
authors.lastname: Mueller
authors.forename: Martin
authors.initials: M
authors.lastname: Stern
authors.forename: Ezio
authors.initials: E
authors.lastname: Bonifacio
authors.forename: Edwin
authors.initials: E
authors.lastname: Liu
mesh_terms: D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002446:Celiac Disease / Q000175:diagnosis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards; D006801:Humans; D007391:International Cooperation; D007753:Laboratories / Q000592:standards*; D012372:ROC Curve; D011869:Radioligand Assay / Q000592:standards; D012680:Sensitivity and Specificity; D011503:Transglutaminases / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D011503:Transglutaminases