WEDNESDAY, Aug. 28, 2002 (HealthDayNews) -- More and more people with diabetes are able to live without insulin after receiving pancreatic islet-cell transplants, say studies being presented this week at the International Congress of the Transplantation Society in Miami.
"Four to five years ago, there was a 10 percent success rate at one year, and now it's over 80 percent," says Dr. Camillo Ricordi, scientific director of the Diabetes Research Institute at the University of Miami School of Medicine.
"There's tremendous progress being made right now with islet-cell transplants that has resulted in several centers in the U.S. beginning programs to duplicate that work," adds Dr. George Loss, director of the Pancreas Transplant Program at the Ochsner Clinic Foundation in New Orleans. "There's a tremendous amount of excitement in the community about the ability to at least control diabetes in many patients."
Some 120 million to 140 million people around the world suffer from diabetes, a condition in which the body's ability to produce the hormone insulin is compromised. Insulin controls blood sugar levels.
If blood sugar levels aren't kept in check, complications can include blindness, heart and blood vessel disease, stroke, kidney failure, amputations, and nerve damage.
Currently, diabetics can only manage their disease. There is no cure. Type I diabetics produce no insulin at all, and must give themselves daily insulin shots. Type II diabetics can often manage their disease, at least in the beginning, with exercise and healthy eating. Restoring the body's ability to make insulin has long been a goal of researchers.
Transplantation of an entire pancreas has had some success, but there are several problems, not the least of which is the severe shortage of donors.
Because islet cells, consisting of less than 10 percent of the pancreas, are involved in insulin production, they have become a major focus of research with innovations now taking place on several fronts.
Ricordi's team in Miami, for instance, is using perflurocarbon (PFC), the standard organ preservative, to enable the shipment of islet cells to distant health centers. Nine patients who received islet-cell transplantations at remote sites were able to come off insulin for varying periods of time.
"It's exciting because it shows that we can have regional centers to process and distribute the islets," Ricordi explains. "This proves the concept that you could process islets in centralized facilities, and distribute them regionally and even across the ocean."
Various other routes to expand the available yield of islet cells are also under study.
Stem cells, "generic" cells which can grow into specialized cells, are a huge focus of research. Scientists hope they will one day be able to coax stem cells into becoming insulin-producing cells, and they have already had some success in animal studies. "It's getting closer, but it's still experimental," Loss says.
Researchers from the Children's Hospital of Mexico and the University of Western Ontario reported at the transplantation meeting that one child who received a mixture of pig islet and testicular cells has been insulin-free for one year without any anti-rejection drugs. Other experts are cautious about hailing the results until they've been duplicated.
There have also been advances in countering rejection of transplanted cells. "A major innovation has been the development of much more effective immune-suppressive drugs," Ricordi says.
Recipients generally have to take immunosuppression drugs for the rest of their lives, to prevent their bodies from rejecting the transplants.
"You cannot really talk about a cure until you perform cellular therapies eliminating the need for anti-rejection drugs for life," Ricordi says. Studies at Ricordi's Diabetes Research Institute found that injections of the cancer drug Samarium-Lexidronam helped the body tolerate the transplanted islet cells.
Research is thus proceeding on all fronts.
"We don't know at this point where the cure will come from," Ricordi says. "It may be adult cells, embryonic stem cells or animal cells. As soon as we find which one is the most effective, we can move forward in that direction and maybe then we will have a preferred source."
What To Do
To learn more about islet cell transplantation, visit the National Library of Medicine. For more information on diabetes, visit the American Diabetes Association.
