Islet transplantation

Abstract

Since the first appreciation of the role of the pancreas in diabetes, investigators have tried to replace the function of the insulin-producing β cells. Because type I diabetes is caused by autoimmune destruction of these β cells, transplanting islets is attractive, although somewhat elusive. Rodent islet transplants were performed in the 1970s, but the application to humans required many advances that spanned a decade. Even after the methods for the automated large-scale isolation of the number and quality of cells required for human investigation were available, it was not until 1990 that the first successful human islet allografts were reported. Human islet autografts were increasingly successful during this period, giving hope for successes with allografts. Long-term results of euglycemia with islet autografts and allografts have now established the feasibility of islet transplantation in humans. Although there are many clear advantages to cellular transplants compared with whole-organ transplants, the success rate is currently unacceptably low because of rejection. Recent developments in the field of organ acceptance and tolerance and the successful use of barrier devices in large animals and recently in humans to protect islet grafts provide real hope that more widespread application of islet transplantation in healthy patients may be possible.