Two-year follow-up of anti-transglutaminase autoantibodies among celiac children on gluten-free diet: Comparison of IgG and IgA

Abstract

Objectives: 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.

• Tissue transgluteminase
• celiac disease
• follow-up
• gluten-free diet
• autoantibodies

Acknowledgements

This work was partially funded by grants from the Spanish Ministry of Health PI03/1053 and RCMN 03/008. AMP is supported by a predoctoral fellowship from the University of the Basque Country. LO was a visiting medical fellow supported by a Nestle Nutrition Scholarship (Vevey, Switzerland). JRB is co-funded by the Spanish Ministry of Health-Human Resources Stabilization Programme. GPN is FIS researcher supported by the Spanish Ministry of Health Fellowships no 03/0064, respectively. The authors are grateful to Arantxa Sainz-Espiga and Sagrario Martinez for technical assistance.