Living Donors Help Diabetics
If at first you don't succeed, try, try again. Such is the lesson learned from a recent experimental surgery in Japan in which doctors implanted pancreatic cells from a living donor into a woman with severe diabetes. Results so far are encouraging -- the woman with diabetes is no longer insulin-dependent. According to David Sutherland, MD, PhD, head, transplant division, and director, Diabetes Institute for Immunology and Transplantation at the University of Minnesota Medical Center, a similar surgery was tried in the 1970s at the University of Minnesota Medical Center, though with unsuccessful results. The recent attempt by Japanese doctors is very encouraging for the possibility of using living donor pancreas tissue donations to aid cases of severe diabetes. To date, most pancreas replacement surgery has involved taking the pancreas from a cadaver, but results have been poor. With live tissue donation, there is a greater chance of not being rejected and of the tissue proliferating.
ABOUT PANCREAS TRANSPLANTS
The pancreas uses groups of pancreatic cells called islets of Langerhans in combination with digestive enzymes to produce insulin. Dr. Sutherland describes the islets as being like BBs scattered throughout the pancreas. However, because the pancreas is made up of two separate parts, each with its own blood supply, it is possible to transplant tissue from a living donor, much as doctors now do routinely with kidneys. Pancreas transplants from living donors sounds like the future, and perhaps it will be, says Dr. Sutherland. People can survive with half a pancreas (or for that matter, no pancreas at all -- though they become instantly diabetic and must take digestive enzymes as well as insulin for life). However, even with the less-invasive islet surgery, the donor requires careful and extensive immunosuppressive medications.
ABOUT THE JAPANESE SUCCESS
The Japanese team removed half the pancreas of a woman, harvested the islet cells and transplanted them to the woman's 27-year-old daughter, who was suffering severe attacks of hypoglycemia. (Most diabetics are able to anticipate and prevent such extreme blood sugar drops, but some are not and they often pass out as a consequence.) The newsworthy aspect is that now, almost a year later, the donor is doing well and her diabetic daughter remains insulin-independent. Part of this latest success may be the fact that the closer the donor and recipient are genetically, the greater the chances of success. Dr. Sutherland says he salutes this effort for its success. Even so, most transplant patients who received their pancreas from a cadaver eventually reject it five or more years later. Transplant surgery is not useful for pancreatic cancer because the cancer is virtually never detected until it has already metastasized. However, for people with diabetes or whose pancreas has been removed because of severe pancreatitis, Dr. Sutherland says doctors hope that someday beta cell islet transplantation from living donors will be routine. In this country, the procedure is still considered investigational and needs approval from the Institutional Review Board and the FDA before doctors can move forward with it. We'll keep watching.