June 6, 2000 (Atlanta) -- Thanks to Canadian researchers, the medical community is one step closer to "curing" type 1 diabetes, a serious medical condition that is usually first diagnosed in children and young adults and requires multiple insulin shots every day for life.
The team, led by A.M. James Shapiro, MD, of the University of Alberta in Edmonton, reports that all seven of their severely afflicted diabetic patients who received islet cell transplants, the cells in the pancreas that produce insulin, have been free of insulin injections since the procedure which, in some cases, is more than a year. The study, which is scheduled to appear in The New England Journal of Medicine in late July, was released early because of the potential impact it could have on the treatment of type 1 diabetes.
"This is a significant finding," Richard Furlanetto, MD, PhD, tells WebMD. "It is truly a great advance as a first step." Furlanetto, a pediatric endocrinologist at the University of Rochester (N.Y.) and the scientific director of the Juvenile Diabetes Foundation, was not involved in the study.
Type 1 diabetes, which affects about a million Americans, occurs when, for some reason, the immune system attacks and destroys the islet cells in the pancreas that normally produce insulin, which regulates the body's blood sugar level. Transplanting a pancreas is one option to restore the production of islet cells -- but the procedure is very complicated, risky and is usually done in conjunction with a kidney transplant, since people with longstanding diabetes often have kidney damage. Instead, researchers had pinned their hopes on islet cell transplants, which can be done without invasive surgery -- but the potential of that procedure has gone unrealized until now. In fact, up until now only about 8% of patients who had undergone islet cell transplants were free from insulin injections after a year.
"It represents proof of something that had been previously suspected, which is to transplant islets instead of pancreases to cure type 1 diabetes," says Furlanetto. "People had long held this out as a goal, but no one had ever been consistently able to do it. The fact that Dr. Shapiro and his team have been able to do it really represents a major advance -- it proves that it can be done."
Shapiro and his team transplanted islet cells into seven diabetic patients who suffered severe ups and downs in their blood sugar to the point of putting some of them in a coma. The risk of the transplant was thus felt to be less than the risk of continued swings in the patients' blood sugars. Each patient received two separate transplants of islet cells that were taken from the pancreas of brain-dead donors. One of the seven needed islet cells from four donors. The patients were also put on a new combination of immunosuppressant therapy. The whole process is called the Edmonton Protocol.
After receiving a transplant, the patient's body views the new cells or organ as a foreign invader and begins attacking them. This is why it's necessary to take medications to suppress the immune system. Most regimens have included steroids, which are strong immune system blockers when taken long term.
Why did the Edmonton team succeed when others have failed? "They've done several things differently," Gordon Weir, MD, tells WebMD. One is that the process used no steroids. "Islets do not seem to like steroids," says Weir. "Two, they are using a larger number of islets than has been typically used in the past. And three, they used fresh islets rather than those [that are grown in the lab]." Weir is the head of the section of islet transplantation and cell biology at the Joslin Diabetes Center in Boston.
"It is a nice advance, but not a major breakthrough and definitely not a cure," warns Weir.
"It is not going to help many patients because first of all you need more than one [dead] donor -- usually two and sometimes three," he says, noting the shortage of donor organs. These drugs come with risks, and "they are going to need to take it as long as the [islet cells are] working. A lot of people are doing so well with their diabetes it would be inappropriate to subject them to the risk of that immunosuppression." Researchers around the world are currently working to overcome the immunosuppressant hurdle.
Because of the long-term need for immunosuppression, both Weir and Furlanetto say the Edmonton Protocol is currently not appropriate for children or for type 2 diabetics, who usually don't require daily insulin shots.
In the meantime, the study findings will have to be reproduced. Furlanetto says, "the first thing that will happen is we will try to duplicate it in other centers around the world. Edmonton's results have been so dramatic that one would expect that other groups will also be able to do this."
For more information on type 1 diabetes, visit the WebMD Illustrated guide.