Data support islet cell therapy for diabetes

An international multicenter trial has validated the Edmonton Protocol for islet cell infusion as a fitting treatment alternative for certain patients suffering from type 1 diabetes. Results appeared in the Sept. 28 issue of The New England Journal of Medicine.

Islet cell transplantation has been around for three decades. The standardized procedure known as the Edmonton Protocol was developed almost a decade ago by Dr. James Shapiro and colleagues at the University of Alberta. It consists roughly of the infusion of pancreatic islet cells from deceased human donors into the portal vein of diabetic patients undergoing an immunosuppressant regimen.

Despite ups and downs, the Edmonton Protocol has produced encouraging results at individual institutions for a number of years. The latest trial is the first, however, to bear results from a coordinated group of research centers in Canada, the U.S., and Europe. Data show the procedure could benefit a specific group of patients with severe complications from type 1 diabetes mellitus.

"This really shows that islet transplantation can be tremendously successful in protecting against hypoglycemic unawareness," Shapiro said.

The clinical trial enrolled 36 adult volunteers, with a mean age of 41, who received between one and three infusions of islet cells. They had lived with diabetes for an average of 27 years. Forty-four percent of these patients no longer needed insulin injections at one-year follow-up, while 28% achieved partial islet function in the same period.

Insulin independence did not last indefinitely in most cases. Fewer than a third of the patients treated remained free from insulin injections after two years, but patients with functioning islets did achieve improved control of their diabetes.

Most patients had at least partial islet function one year after their final islet infusion, and almost all who did had resolution of hypoglycemic unawareness even if they still needed daily insulin injections. Further research could improve and prolong the beneficial effects of the procedure, according to the researchers.

Several clinical sites participated in the trial:

• University of Alberta, Edmonton, Canada

• University of Miami

• University of Minnesota

• Harvard Medical School

• Pacific Northwest Research Institute

• Washington University, St. Louis

• Justis-Liebig University, Giessen, Germany

• University of Milan, Italy

• University Hospital of Geneva, Switzerland

The Immune Tolerance Network, headquartered at the University of California, San Francisco, coordinated the trial. The ITN is an international consortium of clinical investigators supported by the National Institute of Allergy and Infectious Diseases, the National Institute of Diabetes and Digestive and Kidney Diseases, and the Juvenile Diabetes Research Foundation.

For more information from the Diagnostic Imaging archives:

Islet cell therapy quells severe hypoglycemia

Labeling studies follow human stem cell therapies

Islet cell infusions make further gains in diabetes

Islet cell infusions ease diabetes in severe cases