The woman's 56-year-old mother underwent surgery at Japan's Kyoto University Hospital in mid-January to remove roughly half of her pancreas. Insulin-producing cells, known as islet cells, were taken from the removed part of the organ and transfused into her daughter. Once transfused, the islet cells began to produce insulin.
About 500 islet cell transplants have been performed over the past five years using pancreases taken from cadavers. But procedure pioneer James Shapiro, MD, says organs taken from live donors offer several potential advantages.
Toxins produced as a result of brain death and drugs a person might receive before death often damage the pancreas's ability to produce insulin, as does cold storage after the organ is removed from the body.
"In theory, the pancreas from a living donor should function far better than the cadaveric organs," Shapiro tells WebMD. "But it is too early to tell if this is the case."
Approximately 1 million Americans have type 1 diabetes, but most can adequately manage their disease with daily insulin injections.
But despite insulin injections, some patients continue to have dangerous and potentially fatal blood sugar swings.
Shapiro estimates that 10% of people with type 1 diabetes may be candidates for islet cell transplants. Islet cell recipients have to stay on a special combination of immune-suppressing drugs for the rest of their lives to avoid rejection of the donor cells. Theses drugs have significant side effects including increased risks of infections, mouth sores, and stomach problems. They have also been linked to a higher risk of cancer.
Because of the need for these potent drugs, the procedure has mostly been done in patients who are already on such drugs because they have had a kidney transplant.
The woman who received part of her mother's pancreas had been on a cadaver transplant list for several months.Diabetic and On Insulin? Take a Quality of Life Quiz.
Before the surgery, she had frequent, severe low blood sugar episodes that often led to comas. In the weeks following the islet infusion, her blood sugar control stabilized, and Shapiro says she is being weaned off injected insulin.
American Diabetes Association spokesman Eugene Barrett, MD, PhD, says islet cell transplants offer promise for a select group of people with type 1 diabetes, but he adds they remain an experimental procedure.
"We don't really know what the long-term outcome will be for these patients," he says.
Shapiro and colleagues at the University of Alberta in Edmonton, Canada, have performed just over 70 islet cell transplants using cadaver donors. They report that 80% of their patients remained insulin independent, meaning they didn't need injections, after a year. Half of their patients remained insulin independent after three years, but just 10% to 20% were producing enough of their own insulin to avoid injections five years later.
It won't be known for some time if live-donor islet cell transplants produce better long-term outcomes. And Shapiro acknowledges that questions remain about the safety of the procedure for the donor. One fear has been that if too much of the pancreas is removed the donor could also become diabetic.
Barrett says the experience from a French research team is reassuring. For several years the researchers have been doing a similar procedure, only instead of transplanting islet cells from the pancreas they have been transplanting a portion of the pancreas itself from live donors to diabetes patients.
"The donors are not entirely normal in terms of pancreatic function, but they seem to do pretty well," he says. "The fear that they would develop diabetes isn't being borne out."
Shapiro says there are plans to do more live-donor islet cell transplants in both Japan and at his institution in Edmonton.
"We are moving forward cautiously, but I am optimistic that this could supplement or even replace cadaveric transplants," he says. "There are clearly not enough organ donors to go around, and the living donor procedure could fulfill a clear niche. But, obviously, curing diabetes in one person at the expense of creating it in another would be an unacceptable and catastrophic outcome."