Two-year follow-up of anti-transglutaminase autoantibodies among celiac children on gluten-free diet: comparison of IgG and IgA.
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.
Martín-Pagola
Ainhoa
A
Endocrinology and Diabetes Research Group, Hospital de Cruces, Plaza de Cruces s/n, Barakaldo 48903, Bizcaia, Spain.
Ortiz-Paranza
Lourdes
L
Bilbao
Jose Ramon
JR
de Nanclares
Guiomar Pérez
GP
Estevez
Elena Perez
EP
Castaño
Luis
L
Vitoria
Juan Carlos
JC
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
D001323:Autoantibodies; D015809:HLA-DR7 Antigen; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D005983:Glutens; D011503:Transglutaminases