title: Serological tests for celiac disease as indicators of long-term compliance with the gluten-free diet.
abstract: OBJECTIVE
  The efficacy of celiac disease (CD)-related antibodies in monitoring clinical outcome of patients remains unclear. Our aims were to determine dynamics of antibodies after diagnosis and to assess their performances in monitoring patients' long-term compliance with the gluten-free diet (GFD).
  
  
  METHODS
  We prospectively estimated the performance of seven celiac disease-related antibody tests at diagnosis and at 1 year and more than 4 years after treatment initiation in 53 adults. The ability of antibodies to identify patients partially compliant to treatment was explored by the receiver operating characteristic curve analysis. The derived cut-off values ('compliance' cutoffs) were compared with cut-off values used for diagnosis ('diagnostic' cutoffs). The degree of compliance with the GFD was assessed using a standardized, multidisciplinary approach.
  
  
  RESULTS
  Concentrations of all antibodies decreased significantly at 1 year after diagnosis. The decline continued for more than 4 years in strictly compliant patients (P<0.05-0.001). The gap between 'compliance' and 'diagnostic' cut-offs values was wider at 1 year than at more than 4 years. The predictability of partial compliance determined by the area under receiver operating characteristic curves was relevant for most tests examined at 1 year (areas ranging: 0.64-0.72) and more than 4 years (0.58-0.78). Immunoglobulin A antibodies to deamidated gliadin peptides and tissue transglutaminase had the best performance for monitoring long-term compliance.
  
  
  CONCLUSIONS
  Decreased concentrations of antibodies were significantly associated with the degree of compliance with the GFD. Immunoglobulin A antibodies to deamidated gliadin peptides and tissue transglutaminase had the best and more consistent performances. The serial measurement of antibody levels seems to be more reliable in monitoring compliance than the positive/negative expression of results.
authors.affiliation: Department of Medicine, Small Bowel Section, Dr C. Bonorino Udaondo Gastroenterology Hospital, Buenos Aires, Argentina.
authors.forename: Fabio
authors.initials: F
authors.lastname: Nachman
authors.forename: Emilia
authors.initials: E
authors.lastname: Sugai
authors.forename: Horacio
authors.initials: H
authors.lastname: Vázquez
authors.forename: Andrea
authors.initials: A
authors.lastname: González
authors.forename: Paola
authors.initials: P
authors.lastname: Andrenacci
authors.forename: Sonia
authors.initials: S
authors.lastname: Niveloni
authors.forename: Roberto
authors.initials: R
authors.lastname: Mazure
authors.forename: Edgardo
authors.initials: E
authors.lastname: Smecuol
authors.forename: María L
authors.initials: ML
authors.lastname: Moreno
authors.forename: Hui Jer
authors.initials: HJ
authors.lastname: Hwang
authors.forename: María Inés Pinto
authors.initials: MI
authors.lastname: Sánchez
authors.forename: Eduardo
authors.initials: E
authors.lastname: Mauriño
authors.forename: Julio C
authors.initials: JC
authors.lastname: Bai
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000906:Antibodies / Q000097:blood*; D001118:Argentina; D015415:Biomarkers / Q000097:blood; D002446:Celiac Disease / Q000097:blood / Q000175:diagnosis / Q000178:diet therapy* / Q000276:immunology; D055050:Diet, Gluten-Free; D015536:Down-Regulation; D005260:Female; D019204:GTP-Binding Proteins; D005903:Gliadin / Q000276:immunology; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D010446:Peptide Fragments / Q000276:immunology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D012372:ROC Curve; D015203:Reproducibility of Results; D012698:Serologic Tests; D013997:Time Factors; D011503:Transglutaminases / Q000276:immunology; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000906:Antibodies; D015415:Biomarkers; D007070:Immunoglobulin A; D010446:Peptide Fragments; D005903:Gliadin; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins