Pancreatic islet transplantation: A review

457 ABSTRACT: Advances in pancreatic islet transplantation for the treatment of type 1 diabetes have occurred in the past decade. Successful transplantation using the Edmonton protocol has achieved glycemic stability and insulin independence in many recipients. However, the effect of islet transplantation on secondary complications of diabetes is still not clearly understood. The UBC Islet Transplant Program is involved in a study to address this issue by comparing outcomes in transplant recipients with outcomes in patients receiving current best medical management of type 1 diabetes. Future research needs to involve improving islet yield, islet engraftment, immunosuppression regimens, and donor supply. T he success of pancreatic islet transplantation using the Edmonton protocol is a significant landmark in patient care and research in the search for a cure for type 1 diabetes (T1D). It is estimated that there are approximately 20 to 26 new cases of T1D per 100 000 children aged 0 to 14 years in Canada each year. The state of complete insulin deficiency seen in T1D is associated with hyperglycemia and long-term secondary complications involving the kidneys, eyes, nerves, and blood vessels. It has been clearly established that tight blood sugar control reduces the likelihood of developing secondary complications from diabetes. Unfortunately, tight blood sugar control with insulin therapy may not prevent all serious complications of diabetes and is associated with increased frequency of hypoglycemia. The Diabetes Control and Complications Trial (DCCT) findings published in 1993 unequivocally showed that aggressive insulin therapy resulting in near normoglycemia leads to a decreased risk of eye, kidney, and nerve disease when compared with standard insulin treatment. This tighter glucose control was, however, associated with an increased rate of hypoglycemia. Currently, best medical therapy includes more than intensive insulin treatment alone. It includes blood pressure control, blood cholesterol control, and use of protective medications such as angiotensin converting enzyme (ACE) inhibitors. However, even with current best medical therapy, diabetes complications still occur and diabetes has become the leading cause of blindness and kidney disease in adults. The disease often disables people in their middle years and people with diabetes are known to die younger than those not affected. Pancreatic islet transplantation is a new treatment now being tested as an alternative to conventional medical therapy for T1D. Pancreatic islet cells, which can sense blood sugar levels and release the appropriate amount of insulin, can be transplanted to achieve precise glycemic control. Recent successes reported in some programs have enabled islet transplant recipiPancreatic islet transplantation: A review