New study tests islet transplants for severe diabetes

Not all patients with type 1 diabetes are able to achieve good control of their blood sugar with multiple daily insulin injections. Some patients still suffer episodes of dangerously low levels of blood sugar and others — who can’t sense the drop in their blood sugar — may suddenly lose consciousness without warning.

Researchers at Northwestern University’s Feinberg School of Medicine and Northwestern Memorial Hospital have been performing experimental transplants of islet cells — insulin producing cells from the pancreas — for the past ten years to enable these patients to become insulin free or greatly reduce their need for it. Northwestern was the first center in Illinois to perform these transplants.

Now the Feinberg School and the hospital are launching a National Institutes of Health clinical trial for islet transplantation for adults with difficult to control type 1 diabetes and diabetic patients who have had a kidney transplant. Diabetes is the leading cause of kidney failure. Type 1 diabetes cuts lives short by about 15 years, due mainly to heart attacks and strokes.

"This novel approach is appealing because it provides a very specific therapy for the disease and eliminates many of the surgical and post-operative risks associated with pancreas transplantation," said Dixon B. Kaufman, M.D., principal investigator for the Northwestern study (part of an international multi-site study) and professor of organ transplantation as well as vice chair of surgery at the Feinberg School.

"These studies may open the door to more widespread use of islet transplantation for patients with severe type 1 diabetes," said Kaufman, who directs the pancreas and islet cell transplant program at Northwestern Memorial.

The Kaufman laboratory has helped refine the new technology being used in the study for isolating and purifying the islet cells to enhance their viability following transplantation.   

The islet transplants will take place at the hospital, which has built a new state-of-the-art facility for the procedure and trial. In the transplant, islet cells are infused into the bloodstream, which carries them into the liver where they begin to produce insulin to normalise the blood sugar.

Although this research is ongoing and no conclusions are drawn, Kaufman said a majority of the subjects receiving the islet transplants to date have either achieved insulin independence for as long as three years or have required smaller amounts of insulin and had improved blood sugar control and quality of life. Currently, islet cell transplants are effective for three to five years. Patients need to take immunosuppressive drugs to prevent rejection of the islet cells.

Previously, the only other option for patients with hard to control type 1 diabetes was a pancreas transplant. "This offers more options for individuals to become insulin free," Kaufman said.
 
As more expertise is gained with this procedure and anti-rejection medications, more and more people may become candidates for it.
 
"Some day this technology will expand and allow us to transplant insulin producing tissue from expanded lines, for example from stem cells," Kaufman said. "We hope one day it may be possible to isolate some cells from a donor pancreas and be able to multiply those cells a thousand fold, so instead of transplanting one individual, you could transplant 1,000."

He added that the launch of this study is an important milestone marking the beginning of a new era in healthcare in which cellular transplants and regenerative medicine will be accessible to many people with disease, such as diabetes, to return them to a higher and healthier quality of life.

(Source: Northwestern University: May 2008)