Devastating disease
Diabetes actually comprises several disorders. Their common thread is an inability to properly control the amount of glucose circulating in the blood.
Since performing the world's first transplant of insulin-producing islet cells in 1974, David E. R. Sutherland, M.D., Ph.D., has led the way in many other major achievements in diabetes research. Today he is director of the Diabetes Institute for Immunology and Transplantation and holder of the Golf Classic "fore" Diabetes Research Chair.
Normally, when the digestive tract releases energy in the form of glucose into the body, beta cells — found in the pancreas in cell clusters called islets — release insulin. Just as a subway token admits riders through a turnstile, insulin ushers glucose into body cells, where it is used or stored for future energy needs.
In type 1 diabetes, the kind that most commonly appears in childhood, a person's immune system mysteriously destroys his or her beta cells. Traditional treatment involves painstaking daily insulin shots, or infusion. Even with the best of care, many with type 1 diabetes suffer devastating and sometimes deadly side effects, including kidney disease, circulatory problems, and blindness.
Why not replace the destroyed islets with ones that work? In 1966 University of Minnesota surgeons Richard C. Lillehei, M.D., and William D. Kelly, M.D., did just that when they performed the world's first pancreas transplant. Sutherland took the concept one step further in 1974 when he transplanted islets from a deceased donor into a patient with diabetes.
But there are hefty obstacles to overcome before islet transplantation can be considered a viable cure. A major one is improving the effectiveness and reducing the adverse effects of the immunosuppressive drugs used to prevent the recipient's body from rejecting the foreign cells. Another is figuring out how to provide enough islets to meet the demand. Each year about 30,000 Americans are diagnosed with type 1 diabetes, while only about 6,000 donor pancreases become available.
When Sutherland and colleagues established the Diabetes Institute for Immunology and Transplantation in 1994, it was to initiate a full-court press against these obstacles. Two years later they were joined by Hering, a worldwide leader in islet transplant therapy.
We need to have this mindset that diabetes is a curable disease, and we should not accept anything else that will not get us there; anything else will be a compromise.– Bernhard Hering, M.D., associate director of the Diabetes Institute for Immunology and Transplantation
"We need to have this mindset that diabetes is a curable disease, and we should not accept anything else that will not get us there; anything else will be a compromise," says Hering, who holds the Eunice L. Dwan Diabetes Research Chair. "I know it is possible."
In the years since then, the institute has made substantial progress. By developing, testing, and refining various approaches to harvesting and handling islets and preventing rejection, institute staff have been able in clinical trials to reverse diabetes in some islet recipients for years.
Institute staff has stretched the islet supply as well. Last year Hering reported success using islets from a single donor, rather than the two or more normally required. But the availability of islets still remains a serious limiting factor.
"The real advantage of islets is to come in the future, when we can get islets from another source," Sutherland says.