Pancreatic islet transplantation

Type 1 diabetes mellitus is an autoimmune disease, which results in the permanent destruction of β-cells of the pancreatic islets of Langerhans. While exogenous insulin therapy has dramatically improved the quality of life, chronic diabetic complications develop in a substantial proportion of subjects and these complications generally progress and worsen over time. Although intensive insulin therapy has proven effective to delay and sometimes prevent the progression of complications such as nephropathy, neuropathy or retinopathy, it is difficult to achieve and maintain long term in most subjects. Reasons for this difficulty include compliance issues and the increased risk of severe hypoglycemic episodes, which are generally associated with intensification of exogenous insulin therapy. Clinical studies have shown that transplantation of pancreas or purified pancreatic islets can support glucose homeostasis in type 1 diabetic patients. Islet transplantation carries the special advantages of being less invasive and resulting in fewer complications compared with the traditional pancreas or pancreas-kidney transplantation. However, islet transplantation efforts have limitations including the short supply of donor pancreata, the paucity of experienced islet isolation teams, side effects of immunosuppressants and poor long-term results. The purpose of this article is to review recent progress in clinical islet transplantation for the treatment of diabetes.