title: Decrease by 50% of plasma IgA tissue transglutaminase antibody concentrations within 2 months after start of gluten-free diet in children with celiac disease used as a confirming diagnostic test.
abstract: BACKGROUND
  Histological examination of small bowel biopsies is normally the gold standard for the diagnosis of celiac disease (CD). The objective of this study was to investigate whether the rate of decreases in elevated plasma IgA tissue transglutaminase antibody (IgA-tTG) and/or IgG deamidated gliadin peptides antibody (IgG - DGP) concentrations could be used as a confirming test for CD in children on a gluten-free diet (GFD) when biopsy was omitted in the diagnostic process.
  
  
  METHODS
  In this retrospective study we compared children (≤18 years old) with a CD-confirming biopsy (n = 16) to children without a biopsy (n = 18). After initiation of GFD the antibody half-life (the time (T½) when the antibody concentration is 50% decreased) was determined in all children.
  
  
  RESULTS
  Children with a biopsy (IgA-tTG, T½ = 1.9 months; IgG - DGP, T½ = 2.2 months) and children without a biopsy (IgA-tTG, T½ = 1.6 months; IgG - DGP, T½ = 2.7 months) had comparable T½ (mean) results (p < 0.05) supporting that all children had the CD diagnosis.
  
  
  CONCLUSIONS
  When biopsy was omitted a rapid rate of decrease in CD antibody concentrations confirmed the CD diagnosis in children on GFD. The half-lives (T½) of IgA-tTG were less than 2 months in CD children.
authors.affiliation: a Department of Clinical Biochemistry , North Zealand Hospital, University of Copenhagen , Hillerød , Denmark ;
authors.forename: Flemming
authors.initials: F
authors.lastname: Lund
authors.affiliation: b Department of Paediatrics , North Zealand Hospital, University of Copenhagen , Hillerød , Denmark ;
authors.forename: Mette N
authors.initials: MN
authors.lastname: Hermansen
authors.affiliation: a Department of Clinical Biochemistry , North Zealand Hospital, University of Copenhagen , Hillerød , Denmark ;
authors.forename: Merete F
authors.initials: MF
authors.lastname: Pedersen
authors.affiliation: a Department of Clinical Biochemistry , North Zealand Hospital, University of Copenhagen , Hillerød , Denmark ;
authors.forename: Thore
authors.initials: T
authors.lastname: Hillig
authors.affiliation: c Department of Clinical Chemistry, Division of Laboratory Medicine , Skåne University Hospital , Malmö , Sweden.
authors.forename: Ewa
authors.initials: E
authors.lastname: Lavant
authors.affiliation: c Department of Clinical Chemistry, Division of Laboratory Medicine , Skåne University Hospital , Malmö , Sweden.
authors.forename: Camilla
authors.initials: C
authors.lastname: Valtonen-André
authors.affiliation: a Department of Clinical Biochemistry , North Zealand Hospital, University of Copenhagen , Hillerød , Denmark ;
authors.forename: György
authors.initials: G
authors.lastname: Sölétormos
mesh_terms: D000293:Adolescent; D001323:Autoantibodies / Q000097:blood*; D002446:Celiac Disease / Q000097:blood* / Q000175:diagnosis / Q000178:diet therapy; D002648:Child; D002675:Child, Preschool; D005260:Female; D005972:Glutaminase / Q000276:immunology*; D006207:Half-Life; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D007223:Infant; D008297:Male; D016896:Treatment Outcome
chemical_list: D001323:Autoantibodies; D007070:Immunoglobulin A; D005972:Glutaminase
keywords: HLA typing; Immunoglobulin A; diagnostic test; half-life of antibodies; immunoglobulin G