Autoimmune diabetes: gluten is not the trigger

A study conducted by theInstitute of Biochemistry and Cell Biology of the National Research Council in Naples (CNR-Ibbc), carried out in collaboration with pediatricians from the Department of Translational Medicine at the Federico II University, investigated the relationship between type 1 diabetes and celiac disease, two diseases that often occur in association, especially when developed at a young age.

As is well known, type 1 diabetes is an autoimmune disease that mostly arises in pediatric-adolescent age, but can also occur in adulthood, in genetically predisposed individuals: it is caused by poor - or completely absent - production of insulin, a hormone that plays a key role in glucose metabolism. An estimated 300,000 individuals in Italy are affected, corresponding to approximately 0.5 percent of the entire population, about half of whom are of pediatric age. Celiac disease is also a frequent condition and consists of intolerance to gluten proteins contained in cereals. Like type 1 diabetes, celiac disease also has a relevant autoimmune component, characterized by the production of antibodies against tissue transglutaminase, with important diagnostic value.

Because several studies suggest that early exposure to gluten in childhood may be considered a trigger for autoimmune diabetes, this study tried to elucidate, through a trial involving pediatric subjects, how possible gluten-supported inflammation in the intestine may play a role in the self-destructive process of insulin-producing cells (pancreatic betas).

The subjects who participated in the study had diabetes, celiac disease or both: the aim was to observe whether there were signs of inflammatory response to gluten in their intestines by analyzing both the presence of anti-transglutaminase antibodies in serum and the presence of gluten-reactive T lymphocytes in intestinal biopsies. "Our study clearly demonstrates that gluten triggers an inflammatory reaction at the intestinal level only in a subgroup of diabetic children: these are the same children who have anti-transglutaminase antibodies and therefore suffer from comorbid diabetes and celiac disease," explains Carmen Gianfrani (CNR-Ibbc), lead researcher of the study. "Gluten-specific T cells are absent in the gut of diabetics negative for celiac disease: that is, our results show that gluten has a pathogenic role only in a subgroup of diabetics who have developed celiac disease, but does not seem to have it in the majority of diabetics, in whom the causes of the disease must be sought mainly in genetic predisposition and other environmental factors. Which leads to suggest caution in "demonizing" gluten as one of the triggers for autoimmune diabetes."