Tissue transglutaminase and coeliac disease

Coeliac disease (CD) is a permanent intolerance to dietary gluten peptides occurring in genetically predisposed individuals. Ingestion of gluten results in inflammation and effacement of mucosal villi, with consequent mal-absorption of nutrients. Tissue transglutaminase (TG2) has been identified as a major auto-antigen in CD. Earlier reports have presented evidence of elevated activity of TG2 in coeliac biopsy samples and that, by deamidating gliadin, TG2 may enhance intestinal T-cell recognition. Antibodies to gliadin, endomysium and TG2 are markers for CD. Using a large pool of coeliac and control samples we have not found any significant difference in the cross-linking activity of TG2 in coeliacs and non-symptomatic controls. However, we have observed subtle differences in the kinetic properties of TG2 in coeliac samples. We have also performed western blots and observed a greater prevalence of a 60kDa form of TG2 in controls. CD and control TG2 have differential overall charge consistent with a lower isoelectric point in control samples.

Results: Our results suggest some differences in CD and control TG2 that have yet to be unravelled.