Immunological aspects of pancreatic islet cell transplantation

Type 1 diabetes mellitus (T1DM) is one of the most common diseases of childhood. Insulin discovery changed the clinical course of T1DM from an acutely fatal disease to a chronic disease, but this discovery was later found to be inefficient to control its long-term complications. Whole-pancreas and islet cell transplantation seem to provide a potential solution by restoring the normal physiology of glucose-insulin homeostasis. Although islet transplantation is less invasive than whole-pancreas transplantation, the insulin-free state after islet transplantation remained low (10%) at 5 years after surgery. Here, we will present the specific immunologic challenges that are specific to islet cell transplantation, including instant blood-mediated inflammatory reaction and the recurrence of autoimmunity. We will also briefly discuss the immunosuppressive regimens used and the recent radiologic techniques in the detection of engraftment and early rejection of islet cells.