For years, researchers have been looking for ways to literally cure diabetes -- allowing people to do away with daily insulin injections, glucose testing, and meal planning. A major research focus is trying to find ways to transplant healthy "beta islet cells" into diabetic patients. While it will likely be years before the procedures become widely used, the progress remains encouraging.

In one 2001 study of 12 patients, four had normal glucose levels, five had impaired glucose tolerance, and three had post-transplant diabetes. Those who still had diabetes, however, required much less intensive treatment. Larger trials followed. In one study, only 10% of 65 patients were able to be off insulin after 5 years.

The procedure involves the following steps:

• A machine isolates islet cells taken from two separate donors. (The donors are people who have died and donated their organs to medical research.)
• The patient is given intravenous antibiotics and oral vitamins E, B6, and A.
• The islet cells are injected directly in a major vein into the patient's liver.
• The islet cells lodge in the vein, stay there, and produce insulin.

Researchers have found it very tricky to refine the procedure. Many of the fragile donor cells die during the process. In addition, the patient's body tries to reject the donor cells -- thus, the patient needs drugs to suppress the immune system.

These drugs, while they help prevent the body from rejecting the donor cells, nevertheless keep the cells from working properly (which essentially defeats the purpose of the transplant). The drugs can cause serious side effects and are needed for the rest of the patient's life.

The procedure has to be performed two or more times over a period of 2 - 3 months, requiring multiple pancreas donors in order to achieve complete independence from insulin injections.

Clearly, there are some hurdles to be overcome before cell transplantation is a practical cure for diabetes. Various improvements and ideas are being tested, including the use of cloning techniques and pig islet cells. Fortunately, the results continue to be encouraging, so stay tuned.

Organ Transplantation

Whole-pancreas transplants and double transplants of pancreases and kidneys have a good long-term success rate for some Type 1 patients. There is some evidence that heart disease and diabetic neuropathy improves after pancreas transplantation (although not retinopathy).

Life-long use of immunosuppressive drugs are also needed with whole organ transplants, and these drugs have side effects. Transplants are recommended only in certain cases, such as kidney failure or when diabetes poses more of a health threat than does the transplant itself.

Click the icon to see an illustrated series explaining a kidney transplant procedure.

Click the icon to see an illustrated series explaining a pancreas transplant procedure.

References

Ryan EA, Lakey JR, Rajotte RV, et al. Clinical outcomes and insulin secretion after islet transplantation with the Edmonton protocol. Diabetes. 2001;50:710-719.

Ryan EA, Paty BW, Senior PA, et al. Five year follow-up alter clinical islet transplantation. Diabetes. 2005;54:2060-2069.

American Diabetes Association. Pancreas and islet transplantation in type 1 diabetes. Diabetes Care. 2006;29:935.

Pavlakis M, Khwaja K. Transplantation for type 1 diabetes: whole organ pancreas and islet cells. Curr Diab Rep. 2006;6:473-478.