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[IP] Cell Transplants Offer Hope for Severe Cases of Diabetes

Title: Cell Transplants Offer Hope for Severe Cases of Diabetes

A Healthy Me.com
May 27, 2000

Cell Transplants Offer Hope for Severe Cases of Diabetes

In an important advance, researchers in Canada are reporting that transplants of insulin-producing cells have freed eight patients with a severe form of diabetes from insulin injections.

Two to 14 months after being transplanted in a simple procedure resembling a transfusion at the University of Alberta in Edmonton, the cells are still working in all eight patients, half of whom were treated almost a year ago.

The patients, who had Type 1 diabetes, in which the body produces little or no insulin, no longer have any symptoms of the disease. Although they no longer need insulin to control their blood sugar, they now must take other drugs to prevent rejection of the transplants. So far, the researchers report that the only side effect from the drugs has been mild mouth sores, which healed.

The transplanted cells, isolated from the pancreas, were harvested from deceased organ donors. The goal of the treatment is to provide an easier and safer alternative to transplanting the entire pancreas, a major operation that is not commonly done.

"This is something people have wanted for a long time," said Dr. Judith Fradkin, acting director of the division of diabetes, endocrinology and metabolic diseases at the National Institutes of Health in Bethesda, Md. Noting that the procedure worked in eight out of eight patients, Dr. Fradkin said, "If, when it's done in a larger number of patients, you get anything like that success rate, it's a quantum leap."

Dr. Bernard Hering, director of the islet transplant program at the University of Minnesota, said, "This shows that cell transplants can reverse diabetes. Here is something that can really work and can transform a patient's life."

The Juvenile Diabetes Foundation, a nonprofit group that supports research, called the work "a very significant step forward in curing Type 1 diabetes." Type 1 is sometimes referred to as juvenile diabetes.

The diabetes foundation and the health institutes will help pay for a study to test the new procedure within a few months at eight transplant centers in North America and Europe. Each center will treat four patients. The American sites have not yet been named.

Researchers have been trying cell transplants for diabetes for more than 20 years, but most failed, or worked only briefly. The success in eight consecutive patients in Edmonton has been attributed to several factors, like the use of a new combination of drugs to prevent rejection, and the transplantation of many more pancreas cells than in the past.

The pancreas cells are transplanted into the patient's liver, where they lodge in tiny blood vessels and begin doing their normal work of monitoring and regulating blood glucose levels by secreting insulin and another hormone, glucagon.

"They can now control glucose within a very tight range, as in a normal individual," said Dr. Ray Rajotte, director of the pancreatic cell research group at Edmonton.

To perform the transplant, doctors insert a catheter into the patient's abdomen and snake it into the portal vein, which carries blood into the liver. The patient needs only a local anesthetic to numb the skin. About a teaspoonful of cells are injected through the catheter, and they spray out and disperse through the liver. The entire procedure can take as little as 20 minutes. Patients undergo it twice, with a few weeks between transplants, to get enough of the insulin-secreting cells.

Dr. A. M. James Shapiro, part of the 44-member Canadian research team, presented the research last week at medical meetings in Chicago and Washington. It will be published in The New England Journal of Medicine, and an editor, Dr. Robert Utiger, said the study would be posted within about two weeks on the journal's Web site, before it appeared in print. The journal's editors reserve this "early release" policy for papers with especially important implications for patients.

The patients in the Canadian study were 29 to 53 years old. All had severe Type 1 diabetes that was poorly controlled by insulin shots. About a million Americans have the disease, which usually develops early in life. Most need several insulin shots a day.

An additional 15 million are thought to have Type 2 diabetes, in which the body may make insulin, but cannot use it properly. Type 2 tends to come on later in life, and patients may or may not need insulin shots.

Together, the two forms of diabetes cause nearly 200,000 deaths a year in America, and even with treatment they are a leading cause of blindness, kidney failure and amputations.

Dr. Fradkin said that if the Canadian findings were confirmed by other studies, cell transplants would be used first for Type 1 patients. But eventually, she said, they might also be given to some Type 2 patients. For now, Dr. Shapiro recommends the procedure only for severe Type 1 cases.

If the results are confirmed, it will create an unprecedented demand for donor organs, Dr. Fradkin said. The procedure devised in Edmonton required two donor pancreases for every patient treated in order to provide enough of the insulin-producing cells. It costs $100,000.

Other research groups, like those at the University of Minnesota and the University of Miami, are experimenting with techniques they hope will allow them to use one pancreas per patient. Still other scientists are trying to find ways to grow pancreatic cells in culture.

There is great interest in cell transplants because many doctors feel that transplanting the entire pancreas is too big an operation to be an acceptable treatment for diabetes, even though the disease has devastating complications and the surgical success rate matches that of other organ transplants.

"It's a tender issue," said Dr. Paul Robertson, scientific director of the Pacific Northwest Research Institute. "There generally has not been as much acceptance as there has been of heart, liver and kidney transplants. Physicians who don't do it say diabetes is not a life-threatening disease."

That attitude angers some doctors and many patients, but, nonetheless, pancreas transplants are not often performed. Dr. Robertson estimated that doctors did 1,200 transplants a year worldwide, with perhaps half of them in the U.S. The vast majority are done only in people who also need kidney transplants because of renal failure brought on by diabetes. In those cases, many doctors feel the pancreas operation can be justified because the kidney failure demonstrates that the diabetes is out of control, and because the patient will already be on immune-suppressing drugs to prevent rejection of the kidney.

"But patients say, 'Do I have to get kidney failure before I can get a pancreas?' " Dr. Robertson said.

The earliest work on cell transplants was published in 1972, by Dr. Paul Lacey, of Washington University in St. Louis, who showed in rats that the procedure could cure diabetes. Dr. Lacey transplanted the pancreatic tissue known as islets of Langerhans, which makes up only 3 percent of the pancreas but contains all the insulin-producing cells, called beta cells.

"Everybody thought, this is how we'll cure diabetes," Dr. Robertson said. But when researchers tried the procedure in people, it usually failed. Occasionally, the islets would function for a few weeks, sometimes longer. Doctors could not explain it.

But during the 1990's, they began to suspect that standard anti-rejection drugs like steroids and cyclosporine might be damaging the islets, because the islets sat in the liver, where those drugs become most highly concentrated.

"There were plenty of hints in the medical literature" that the drugs needed to be changed, Dr. Robertson said. "But Edmonton gets the credit. They went ahead and did it."

Instead of steroids and cyclosporine, the Edmonton team used a combination of three other antirejection drugs, tacrolimus, sirolimus and daclimuzab.

But Dr. Rajotte said the drugs alone could not account for the group's success. He said it helped that the patients did not have kidney failure and therefore were in an earlier stage of the disease than were those in other studies. In addition, he said, the new work was based on 30 years of research on how to isolate healthy insulin-making cells from the rest of the pancreas.

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