Needle-Free Diabetes Therapy Has Setback
Some in groundbreaking program back on insulin
WEDNESDAY, June 13, 2001 (HealthDayNews) -- A year ago, Canadian researchers announced a landmark treatment for Type I diabetes that freed a small group of patients from daily insulin shots for as long as a year.
The treatment, a transplant of insulin-producing islet cells from the pancreas and a regimen of drugs for the immune system, was so successful that it was expanded from seven patients to 15. Three more are just getting started.
But a year later, the success is somewhat tempered. Though the doctors still believe the needle-free treatment is better than anything that came before it, five of those 15 patients are back on the daily shots typical of the disease.
"We of course would have liked 100 percent success. But this is better than any other prior" attempt at transplanting islet cells, says Dr. Edmond Ryan, medical director of the islet cell transplant program, now known as the Edmonton Protocol.
For nearly 40 years, Robert Teskey was a slave to needles. Diagnosed with diabetes as a child, Teskey needed daily shots of the hormone insulin to keep his blood sugar in balance.
Blood sugar levels kept in check
All that changed two years ago, when the Edmonton lawyer, now 54, enrolled in a University of Alberta study to give him insulin-producing islet cells harvested from dead people. Type I diabetics like Teskey destroy their own islet cells though a mutiny of their immune system, and gradually lose the ability to generate the hormone, which helps muscles convert glucose into energy.
Before the islet cell grafts, Teskey's blood sugar levels fluctuated wildly, dropping to 2 on the Canadian glucose scale and spiking to 30 in a single day. "The high and low swings really do dramatically sap your energy and can ruin a day. And you have those swings most days," Teskey says. Since the procedure, Teskey says his blood glucose hovers in a range between 5 and 7 -- healthy and normal.
And the blackouts and weakness? "That doesn't happen at all any more," he says.
Then there's Don Cammidge. Cammidge, of Edmonton, is one of the patients for whom the transplant procedure has been bittersweet. One of the first to get the grafts in December 1999, the 36-year-old furniture store owner is now on his third set of islet cells, having lost most of the first two to viral infections last winter and earlier this spring.
"I have to take a little bit of insulin still at night, but the situation's better than it used to be. It's a lot better."
The Alberta researchers have now completed the grafts in 15 patients and have three more in the early stages of the procedure. Of that group, 10 -- including Teskey -- no longer need daily insulin but five others have backslid, says Ryan.
The scientists are now investigating why the grafts have worked better in some patients than in others, analyzing blood samples and other characteristics for clues.
Islets normally reside in the pancreas, but the transplanted cells, some 800,000 in all, are injected into the liver. Some are almost certainly dying off, but how many and why isn't clear, says Ryan, who will present a roundup of the program's progress and the early findings this month at a meeting of diabetes researchers.
Islet grafts "can help a small number of patients, but as far as really helping the diabetes problem, it will really be unavailable," says Dr. Gordon Weir, of Harvard University's Joslin Diabetes Center in Boston.
Weir, who is recruiting patients for his own study of the Edmonton procedure, says he expected the transplants to meet with less-than-universal success. "I'm not surprised that some of them would have failed, and I assume more will fail. I never thought it would be a lifetime of normal blood sugars."
Several other research centers, including the University of Miami, the University of Minnesota and institutes in Europe, are performing islet cell transplants using procedures similar to the Edmonton Protocol. While these trials are important in the effort to cure diabetes, Deb Butterfield, executive director of the Insulin Free World Foundation in St. Louis, says the more significant breakthrough will come when scientists can graft islets without needing an entire pancreas to gather the cells.
Roughly 5,000 pancreases a year are available for transplant in the United States, and of those only about 1,500 of the operations are performed, Butterfield says. Current islet cell transplants require at least one if not two pancreases per patient, she says, where ideally the situation would be two or three patients per organ.
Still, with about 1.5 million Type I diabetics in the United States alone -- compared with 15 million with Type II (non-insulin-dependent) diabetes -- the number of donor pancreases will never meet the demand for them.
"We have to move toward cell therapies," such as stem cell manipulation or cloning, says Butterfield.
Another important breakthrough will be finding ways to obviate immune-suppressing drugs that keep the body from rejecting transplanted tissue, Butterfield says. Researchers in Miami are now following a patient who received a bone marrow transplant in addition to islet cells as a way to prime his immune system to accept the donor tissue.
But bone marrow transplants, which are themselves traumatic, may not be necessary, says Ryan, who cites recent animal studies showing that it may be possible to wean graft recipients off drugs yet maintain the donor cells. "There's hope," Ryan says. "But it's very early days yet."
Teskey, who keeps in touch with his fellow transplant recipients, admits that he's among the fortunate ones. "For me it has gone amazingly well," says Teskey. "I'm now two years out from the transplants and have been off insulin completely for that entire time."
Not only that, but he has been spared the worst of the immune-suppressing regimen, though he does have to watch for surges in his blood pressure and in the beginning he was plagued by painful mouth sores. "Those minor difficulties are really very insignificant in comparison with the positive change in my life," he adds.
A 'rough time,' but no regrets
Dale Camp, another transplant recipient, hasn't been so lucky. The grafts, placed in May and June of 1999, helped stabilize Camp's blood sugar. But the immune-quelling drugs have been murder. "The islets have done reasonably well, but the side effects have been quite poor," Camp says. "I've had a pretty rough time."
Diarrhea and trouble absorbing food have dropped his weight from 150 pounds to as low as 115 pounds, though lately it has come up a bit. Apparently unrelated to the drugs, his white blood cell count plunged to "next to nothing."
"They've given me quite a ride," Camp says of the medications, in his case tacrolimus and Rapamune. Still, Camp, who was diagnosed with diabetes in 1949 at the age of 2, doesn't feel he made a mistake enrolling in the trial. "I was in a push-and-shove-type situation. I was hypo-unaware and had severe insulin reactions many times a day or week. It was just a matter of time before I didn't wake up from one." Keeping his insulin in line "is not only good for me, it's good for my wife and everyone around me as well," Camp says.
Yet Camp, who lives in Falun, Alberta, is philosophical about the tradeoff, and says it was a risk he was willing to take. "If you wish to keep your transplant, you have to maintain some sort of a level of immune suppression, and you're going to be with it the rest of your life. We're a new technology here, and everybody's learning and everybody's very individual," he adds. "For some people it works and for some people it might not. That's sort of the luck of the draw."