Where do we get islets for transplantation ?
Islets are obtained from the pancreas of someone who has died. Donors or their relatives have given permission to use their organs for transplantation and research. Great care is used to select a healthy pancreas for an islet transplant. Special solutions and procedures are used to free the islet cells, which can only be seen under a microscope, from the donor pancreas. The processing of the islets takes about 6 to 8 hours.
In some studies, it took about 10,000 islet equivalents (IE) per kilogram of body weight for each patient to be free from insulin injections for a limited time. That would be approximately 700,000 islets for a person weighing 154 pounds. It takes 2-4 pancreases to get that many islets.
Can a living family member or friend donate islets ?
Frequently, a family member will offer to donate islets to someone with diabetes. Although attempts have been made in the past to transplant islets from a living donor, the islets are obtained by taking part of the donor’s pancreas, and the number of islets from a partial pancreas is not enough to get a patient free of insulin shots. Secondly, with removal of part of the pancreas, the donor may have a greater risk for developing diabetes later in life.
Are transplanted islet cells an option?
Researchers in the area of islet transplantation believe the answer is yes. As early as 1989, studies proved that transplanted islets could make insulin and result in normal blood sugars. However, not much progress was made during the next 10 years. With recent success, the number of islet transplant research studies is growing once again.
What is happening in islet research now ?
Researchers report success in getting several people off insulin shots for a limited time through islet transplantation. The “Edmonton Protocol” is a research study that uses antirejection drugs without steroids and gives separate islet transplants over a one- to two-month period. Of the first 7 patients receiving this experimental treatment, all were able to be free of insulin shots for a prolonged period. As a result, multicenter clinical research trials have begun in the area of islet transplantation for the first time in history. These studies are sponsored by the Immune Tolerance Network (ITN) and are funded through the National Institutes of Health (NIH). Other centers are doing islet transplant research as well. The results of these studies will help determine whether islet transplantation can become a future treatment of choice for type 1 diabetes. Other researchers are working on encapsulating (coating) islets to eliminate the need for anti-rejection drugs.
How are islets transplanted ?
An islet transplant is done under local anesthesia. A small area of skin on the abdomen is injected with a medicine to numb the area during the procedure. A radiologist injects the islets through a small tube into the liver, where they are nourished by the liver’s blood supply. The islets start making insulin immediately when transplanted. If conditions are right, the islets will attach in the liver and continue making insulin in response to blood sugar levels in the body. Most patients are in the hospital only 1 to 3 days.