Poster Presentation The 13th International Congress of the Immunology of Diabetes Society 2013

CD8 infiltration of the exocrine pancreas is a common pathological feature of human type 1 and type 2 diabetes (#114)

Teresa Rodriguez-Calvo 1 , Ghanashyam Sarikonda 1 , Natalie Amirian 1 , Sowbarnika Sachithanantham 1 , Matthias von Herrath 1 2
  1. La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
  2. Novo Nordisk Diabetes Research & Development Center, Seattle, Washington, USA

Type 1 diabetes (T1D) results from a complex interplay between varying degrees of genetic susceptibility and environmental factors which have been implicated in the pathogenesis of disease both as triggers and potentiators of beta cell destruction. Activated T cells, and more specifically CD8 T cells, are the main cell type implicated in the pathogenesis of the disease and when exposed chronically to low doses of antigen, are significantly skewed toward a proinflammatory phenotype. Here we report that CD8 T cells are abundant in the exocrine pancreas of diabetic subjects, and not only in the endocrine areas. Autoantibody positive, T1D and T2D subjects present significantly higher CD8 T cell density in the pancreas without the presence of prominent insulitis, indicating that there is spontaneous infiltration of the exocrine pancreas and not only of the islets. CD8 T cells are present in the exocrine pancreas in large numbers even in diabetic subjects without remaining insulin containing islets (ICIs), which indicates a possible major role of the exocrine pancreas in the initiation/development of disease. Our study provides the first information on the precise tissue distribution of CD8 T cells in healthy, pre-diabetic and diabetic subjects and could point towards a hence unknown cause for this disease that is not exclusively autoimmune in nature.