Serum transglutaminase 3 antibodies correlate with age at celiac disease diagnosis

Background: Transglutaminase (TG)2 is the autoantigen in celiac disease, but also TG3 antibodies have been detected in the serum of celiac disease patients. Aims: To investigate the correlations between serum TG3 antibodies and clinical and histological manifestations of celiac disease and to assess gluten-dependency of TG3 antibodies. Methods: Correlations between serum TG3 antibody levels measured from 119 adults and children with untreated coeliac disease and the demographic data, clinical symptoms, celiac antibodies, histological data and results of laboratory tests and bone mineral densities were tested. TG3 antibodies were reinvestigated in 97 celiac disease patients after 12 months on a gluten-free diet (GFD). Results: TG3 antibody titers were shown to correlate with the age at celiac disease diagnosis. Further, negative correlation with TG3 antibodies and intestinal gamma delta+ cells at diagnosis and on GFD was detected. Correlations were not detected with the clinical manifestation of celiac disease, TG2 or endomysial autoantibodies, laboratory values, severity of mucosal villous atrophy, associated diseases or complications. TG3 antibody titers decreased on GFD in 56% of the TG3 antibody positive patients. Conclusion: Serum TG3 antibody positivity in celiac disease increases as the diagnostic age rises. TG3 antibodies did not show similar gluten-dependency as TG2 antibodies. (C) 2016 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.