title: Two-year follow-up of anti-transglutaminase autoantibodies among celiac children on gluten-free diet: comparison of IgG and IgA.
abstract: OBJECTIVE
  To investigate the evolution of IgA and IgG autoantibodies against tissue transglutaminase (tTGase) in celiac patients on gluten-free diet (GFD).
  
  
  METHODS
  IgA and IgG anti-tTGAse autoantibodies was evaluated in 93 patients (58 girls and 35 boys; mean age 3.56 +/- 3.04 years; range 0.94-17.5 years) at diagnosis of celiac disease and after 1, 2, 4, 6, 12, 18, 24 months of follow-up on GFD. Autoantibodies were measured with a radioassay using in vitro transcribed-translated human recombinant tTGAse, and immune complexes were precipitated with protein A- or anti-IgA-agarose for IgG and IgA, respectively.
  
  
  RESULTS
  Autoantibody titers started to decline very soon after removal of gluten, and no significant differences in the decrease rate between IgG and IgA antibodies were observed. After 6 months on GFD, 63 and 49% of the patients were negative for IgG and IgA, respectively. Patients who remained autoantibody-positive after 6 months of treatment initially presented with significantly higher titers at the time of diagnosis compared to patients that had lost their antibodies by that time. Children diagnosed before the age of two years presented lower autoantibody titers, while patients positive for HLA-DR7 had higher anti-tTGase levels, especially IgA.
  
  
  CONCLUSIONS
  There are no differences in the performance of IgG and IgA class autoantibodies in the evolution of celiac patients. Between 3 and 6 months on GFD, almost half of the patients are negative for anti-tTGase antibodies. In our experience, they can be of help in evaluating compliance with diet, at least during the first two years of treatment.
authors.affiliation: Endocrinology and Diabetes Research Group, Hospital de Cruces, Plaza de Cruces s/n, Barakaldo 48903, Bizcaia, Spain.
authors.forename: Ainhoa
authors.initials: A
authors.lastname: Martín-Pagola
authors.forename: Lourdes
authors.initials: L
authors.lastname: Ortiz-Paranza
authors.forename: Jose Ramon
authors.initials: JR
authors.lastname: Bilbao
authors.forename: Guiomar Pérez
authors.initials: GP
authors.lastname: de Nanclares
authors.forename: Elena Perez
authors.initials: EP
authors.lastname: Estevez
authors.forename: Luis
authors.initials: L
authors.lastname: Castaño
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Vitoria
mesh_terms: D000293:Adolescent; D001323:Autoantibodies / Q000097:blood*; D002446:Celiac Disease / Q000178:diet therapy / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D018753:Diet, Protein-Restricted; D005260:Female; D005500:Follow-Up Studies; D005983:Glutens / Q000008:administration & dosage*; D015809:HLA-DR7 Antigen / Q000097:blood; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood* / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood* / Q000276:immunology; D007223:Infant; D008297:Male; D011503:Transglutaminases / Q000097:blood* / Q000276:immunology
chemical_list: D001323:Autoantibodies; D015809:HLA-DR7 Antigen; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D005983:Glutens; D011503:Transglutaminases