Immunosuppressive Drugs After Pancreatic Islet Transplantation

The Edmonton protocol uses a combination of immunosuppressive drugs, also called antirejection drugs, including dacliximab (Zenapax), sirolimus (Rapamune), and tacrolimus (Prograf). Dacliximab is given intravenously right after the transplant and then discontinued. Sirolimus and tacrolimus, the two main drugs that keep the immune system from destroying the transplanted islets, must be taken for life.

These drugs have significant side effects and their long-term effects are still not known. Immediate side effects of immunosuppressive drugs may include mouth sores and gastrointestinal problems, such as stomach upset or diarrhea. Patients may also have increased blood cholesterol levels, decreased white blood cell counts, decreased kidney function, and increased susceptibility to bacterial and viral infections. Taking immunosuppressive drugs increases the risk of tumors and cancer as well.

Researchers do not fully know what long-term effects this procedure may have. Also, although the early results of the Edmonton protocol are very encouraging, more research is needed to answer questions about how long the islets will survive and how often the transplantation procedure will be successful.

A major obstacle to widespread use of islet transplantation will be the shortage of islet cells. The supply available from deceased donors will be enough for only a small percentage of those with type 1 diabetes. However, researchers are pursuing avenues for alternative sources, such as creating islet cells from other types of cells. New technologies could then be employed to grow islet cells in the laboratory.

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