β-Cell replacement therapy (pancreas and islet transplantation) for treatment of diabetes mellitus: An integrated approach

Type 1 diabetes (T1D) continues to represent a therapeutic challenge. Complications from secondary diabetes, observed in 30% to 50% of patients affected by T1D, result in poor quality of life, premature death, and considerable health care costs [1]. The principal determinant of the risk of devastating diabetes complications is the total lifetime exposure to elevated blood glucose levels [2]. Therefore, establishing safe and effective methods of achieving and maintaining normoglycemia will have substantial implications for the health and the quality of life of individuals who have diabetes. The Diabetes Control and Complications Trial demonstrated that, given a qualified diabetes care team and intensive insulin treatment control, near-normalization of glycemia could be achieved and sustained for several years. Such a near-perfect level of treatment, however, would increase a patient's burden of day-to-day diabetes management, be difficult to implement for many patients, require more attention and medical services than are routinely available in clinical practice [3], and be accompanied by an increased frequency of severe hypoglycemia [2]. Currently, the only way to restore sustained normoglycemia without the associated risk of hypoglycemia is to replace the patient's glucose-sensing and insulin-secreting pancreatic islet β-cell islets, either by the transplantation of a vascularized pancreas or by the infusion of isolated pancreatic islets [4].