Pancreatic Islet Transplantation: Benefits, Risks, and Obstacles

The goal of islet transplantation is to infuse enough islets to control the blood glucose level without insulin injections. For an average-size person (70 kg), a typical transplant requires about 1 million islets, extracted from two donor pancreases. Because good control of blood glucose can slow or prevent the progression of complications associated with diabetes, such as nerve or eye damage, a successful transplant may reduce the risk of these complications. But a transplant recipient will need to take immunosuppressive drugs that stop the immune system from rejecting the transplanted islets.

Researchers are trying to find new approaches that will allow successful transplantation without the use of immunosuppressive drugs, thus eliminating the side effects that may accompany their long-term use.

Rejection is the biggest problem with any transplant. The immune system is programmed to destroy bacteria, viruses, and tissue it recognizes as "foreign," including transplanted islets. Immunosuppressive drugs are needed to keep the transplanted islets functioning.

source: http://diabetes.niddk.nih.gov/dm/pubs/pancreaticislet/index.htm