MONDAY, April 18, 2005 (HealthDayNews) -- The first successful operation to transplant insulin-making cells, called islets, from a living donor has allowed a woman to stop using daily insulin to treat her diabetes, according to a study led by Japanese researchers.
"The success of our first case is remarkable," said study co-author Dr. James Shapiro, director of the clinical islet transplant program at the University of Alberta, Canada. "It could open up the door for many more patients to be treated with islet transplants."
Islet-transplant surgery was first performed in 2000 using islets from deceased donors. However, the demand for islet transplantation has increased so fast there is a danger that donors will soon be in short supply. Using living donors is a way to increase the available donor pool, the scientists said.
There had been two previous attempts in the United States to transplant islets from living donors, both of which failed.
Some scientists say the new study's findings are preliminary and more research is needed.
In islet transplantation, islets are taken from a donor's pancreas and transferred into another person. Once implanted, the cells in these islets start to make and release insulin. The hope is that islet transplantation will let people with type 1 diabetes live without daily injections of insulin.
In type 1 diabetes, the body does not produce insulin, a hormone. Insulin is needed for the body to use sugar, the basic fuel for all cells.
In this study, a 56-year-old Japanese woman donated her islets to her 27-year-old daughter, who had developed diabetes when she was 15 as a result of pancreatitis, an inflammation of the organ. Shapiro believes living donor transplantation will also work well with those born with type 1 diabetes.
The mother was acceptable as a donor because she had a compatible blood type and healthy sugar and insulin levels, according to the report in the April 19 online edition of The Lancet.
The transplants functioned immediately and the recipient became insulin-independent 22 days after the operation. During 40 days of follow-up, the transplant continued to function normally. Since then, "the transplant is doing perfectly," Shapiro said. The woman has now remained free of the need for insulin injections for two months.
Shapiro stressed that there are risks in the procedure: The donor can develop diabetes, because of the loss of half the pancreas. In addition, there is risk of transplant rejection by the recipient.
As for the operation itself, "It's not a particularly dangerous operation," Shapiro said. "It's not as risky as removing half a liver for living donor liver transplant, or half a lung."
Shapiro believes this procedure may one day become standard therapy. "There aren't enough islets to go around and treat all the patients with type 1 diabetes that could benefit," Shapiro said. "The success of this first effort demonstrates that transplantation from a living donor can work."
In an accompanying commentary in the journal, U.K. experts Stephanie Amiel, a professor of medicine at King's College, and Dr. Mohamed Rela, of King's College Hospital, both in London, note that, "Until now, islet transplant programs have used cadaveric donors. In Japan, cultural considerations severely restrict the use of cadaveric donors. For a patient with crippling hypoglycemia in such societies, the only realistic donor source would be a living donor."
However, they cautioned that "islet transplantation is not yet a perfect technique. Insulin independence is by no means certain, and is only likely in the very insulin sensitive."
Another expert, Dr. Jennifer Larsen, director of the clinical research center at the University of Nebraska Medical Center, questioned the value of the procedure when the lifespan of the transplanted islets is unknown, and might only be two years. She said the long-term risk for the donor of developing their own case of diabetes is also unknown.
"While the results of this study are provocative, long-term studies of both the donor and recipient are certainly needed before this technique should be recommended," she said. "The long-term risk of diabetes for the donor must be taken into consideration even if there is time-limited benefit to the recipient."
Larsen's comments were echoed by Dr. Craig Smith, the co-director of the Southern California Islet Resource Center and an associate professor of diabetes at the City of Hope National Medical Center, in Duarte, Calif.
"The findings are interesting, but I'm not surprised," Smith said. "Using a live donor for this sort of thing raises a lot of issues."
Smith also questioned whether the risk to the donor is worth the unknown benefit to the recipient. For the donor, the operation is riskier than a live donor kidney operation, Smith said. "It's closer to a liver transplantation, where there have been deaths. With that in mind, you have to look at what is the recipient benefit relative to the donor risk."
Smith doesn't believe that most type 1 diabetics need islet transplantation if their condition is being controlled by insulin. He also thinks that islet transplants from dead donors work as well.
"In addition, if this is only going to provide a short-term benefit, it may not be worth it," he said. Smith noted that patients who have received dead donor islet transplants are back on insulin after a couple of years, and he suspects that their condition will regress to a pre-transplant level over time.
"Islet transplant itself should not be recommended for every type 1 diabetic," Smith said. "Using islets from cadaveric donors are as good as this. At this point, there is no clear benefit to using a live donor."
More information
The National Diabetes Information Clearinghouse can tell you more about pancreatic islet transplantation.
