The Edmonton protocol involves isolating islets from a cadaveric donorpancreas using a mixture of enzymes called Liberase. Each recipient receives islets from one to as many as three donors. The islets are infused into the patient's portal vein, and are then kept from being destroyed by the recipient's immune system through the use of two immunosuppressants, sirolimus and tacrolimus as well as a monoclonal antibody drug used in transplant patients called daclizumab.
History
Islet isolation and transplantation was pioneered by Paul Lacy throughout the 1960s. He and Walter Ballinger together were able to restore normoglycaemia in diabetic rats following the transplantation of isolated islets into the rodent's livers. Scientists have not yet successfully translated Lacy's success in rodents to humans. The Edmonton protocol was primarily developed by James Shapiro, Jonathan Lakey Ph.D., Dr Edmond Ryan, Gregory Korbutt Ph.D., Dr. Ellen Toth, Dr. Garth Warnock, Dr. Norman Kneteman, and Ray Rajotte Ph.D., at the University of Alberta Hospital and the Surgical-Medical Research Institute. The first patient was treated using the Edmonton protocol in March 1999. The protocol was first published in the New EnglandJournal of Medicine in July 2000. The NEJM report was exciting for the diabetes field because the seven patients undergoing the Edmonton protocol remained insulin-independent after an average of 12 months.
Current review
It has been reported that of thirty-six patients transplanted, only sixteen were insulin-independent after one year; ten had partial graft function after one year; and ten had complete graft loss after one year. Insulin independence is not usually sustainable in the long term, but the transplanted islets still function enough to provide protection from severe hypoglycemic episodes and unawareness. A webpage maintained by the National Institute of Diabetes and Digestive and Kidney Diseases of the U.S. National Institutes of Health indicates that the 's The major problem limiting islettransplantation therapy for type 1 diabetic individuals is the lack of organ donors. Citing the Organ Procurement and Transplantation Network, a NIDDK webpage says that "in 2011 there were about 8,000 deceased organ donors available in the United States. However, only 1,562 pancreases were recovered from donors in 2011. Also, many donated pancreases are not suitable for extracting islets for transplants because they do not meet the selection criteria, and islets are often damaged or destroyed during processing. Therefore, only a small number of islet transplants can be performed each year. "Since 2000, Several hundred people have received islet transplants, by a year after transplant, 50 - 68% of patients do not need to receive additional insulin, but by five years after the procedure, fewer than 10% of total patients are free of daily insulin supplementation."
