title: Deamidated gliadin peptide antibodies as a routine test for celiac disease: a prospective analysis.
abstract: OBJECTIVE
  This study was designed to establish whether deamidated gliadin peptide antibodies (DGP-AGA) could improve the serologic workup for celiac disease (CD).
  
  
  BACKGROUND
  The best serologic approach for CD screening is currently based on the combined detection of tissue transglutaminase (tTGA), endomysial (EmA), and gliadin antibodies (AGA).
  
  
  METHODS
  One hundred forty-four consecutive patients with gastrointestinal and extraintestinal signs suggestive for CD were investigated using serologic tests, that is, IgG and IgA DGP-AGA, IgA tTGA, IgA EmA, and duodenal biopsy.
  
  
  RESULTS
  Forty-eight out of 144 patients (33%) had CD with different severity of villous atrophy. IgA tTGA showed 93.7% sensitivity compared with 91.6% for IgA EmA, 84.3% for IgA DGP-AGA, and 82.3% for IgG DGP-AGA. Of the 3 cases negative for IgA tTGA, IgA EmA, and IgA DGP-AGA, 2 had total IgA deficiency, although both were positive for IgG DGP-AGA. IgG DGP-AGA showed a very high specificity for CD (98.9%), not only superior to IgA DGP-AGA (79.8%), but also to IgA tTGA (96.6%) and very close to IgA EmA (100%).
  
  
  CONCLUSIONS
  Our prospective study shows that the combined search for IgA tTGA and IgG DGP-AGA provides the best diagnostic accuracy for CD, allowing the identification of all CD cases---except one---with a very high specificity. The serologic workup for CD screening could be significantly improved by the routine introduction of IgG DGP-AGA together with IgA tTGA, thus reducing the number of tests and with an obvious advantage in terms of cost-efficacy.
authors.affiliation: Department of Clinical Medicine, University of Bologna, Bologna, Italy. umberto.volta@aosp.bo.it
authors.forename: Umberto
authors.initials: U
authors.lastname: Volta
authors.forename: Alessandro
authors.initials: A
authors.lastname: Granito
authors.forename: Claudia
authors.initials: C
authors.lastname: Parisi
authors.forename: Angela
authors.initials: A
authors.lastname: Fabbri
authors.forename: Erica
authors.initials: E
authors.lastname: Fiorini
authors.forename: Maria
authors.initials: M
authors.lastname: Piscaglia
authors.forename: Francesco
authors.initials: F
authors.lastname: Tovoli
authors.forename: Valentina
authors.initials: V
authors.lastname: Grasso
authors.forename: Paolo
authors.initials: P
authors.lastname: Muratori
authors.forename: Georgios
authors.initials: G
authors.lastname: Pappas
authors.forename: Roberto
authors.initials: R
authors.lastname: De Giorgio
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000906:Antibodies / Q000276:immunology; D002446:Celiac Disease / Q000175:diagnosis* / Q000276:immunology; D005260:Female; D005903:Gliadin / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D011503:Transglutaminases / Q000276:immunology; D055815:Young Adult
chemical_list: D000906:Antibodies; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D005903:Gliadin; D011503:Transglutaminases