Strategic opportunities in clinical islet transplantation

More than 471 patients with type 1 diabetes have received islet transplants at 43 institutions worldwide in the past 5 years. High rates of insulin independence have been observed at 1 year in the leading islet transplant centers, and an international multicenter trial has demonstrated reproducible success of the approach. Loss of insulin independence by 5 years in the majority of recipients remains of concern, and immunosuppressant drug side effects necessitate stringent inclusion criteria for islet-alone candidates that have the most severe, unstable glycemic control despite optimal insulin therapy. The advent of new immunosuppressive drugs with superior side-effect profiles (e.g., LEA29Y and FTY720) may open up opportunities for more '' islet- friendly '' approaches. Future opportunities to expand the donor pool using living donor islet transplantation are within reach, and will be enhanced considerably with both donor and recipient adjunctive treatment using islet-specific growth-factors.