Islet cell transplants have been discussed for years as a possible cure for type 1 diabetes. Though there have been some encouraging studies, researchers have not yet been able to figure out the many puzzle pieces in order to make this procedure safe and effective. Here are some of the most frequently asked questions and what we currently know.
What are pancreatic islet cells?
The pancreas has clusters of cells called islets of Langerhans that contain beta cells. These beta cells are responsible for making insulin. When these cells stop producing insulin or produce so little that the body cannot process the food that is eaten, diabetes is the result.
How is a pancreatic islet cell transplant performed?
Islet cell transplantation involves transferring the islet cells from the pancreas of a deceased donor to the person with diabetes. Before they are placed in the recipient they are purified and processed to increase the likelihood that they will not be rejected by the recipient. Once the islet cells are implanted, the beta cells in these islets begin to make insulin. The hope is that enough insulin is made to regulate the blood sugar in a normal manner.
What are the potential benefits of an islet cell transplant?
If the islet cell transplant is successful, the pancreas will begin to monitor the sugar in the blood and release the appropriate amounts of insulin to keep glucose levels in a normal range. This eliminates the needs for insulin injections and multiple blood sugar checks each day. This also significantly reduces the future risk of diabetes-related complications.
What are the risks of an islet cell transplant?
Currently, islet cell transplants are considered an experimental procedure and there are risks. Perhaps the greatest risk is that your body might reject the islet cells that are transplanted. Because these cells come from another person, your body’s immune system “reads” these cells as an invader and tries to destroy them. To protect against this immune system attack, all transplant recipients must take strong drugs for the rest of their lives that prevent rejection of the new islet cells. These drugs can have serious side-effects and the long-term consequences of taking these drugs are not yet known.
The other risk is that the islet cells may eventually stop working. In studies where islet cells transplants have been performed, most recipients have been insulin-free for limited periods of time, ranging from a few months to about five years. But the islets stop producing insulin, in most cases, after about a year.
What current research is being done on islet cell transplantation?
Researchers continue to work on new drugs that they hope will extend the life of the transplanted islets and reduce the potential side-effects of the immune suppression drugs. One study is testing the transplantation of islets that are encapsulated with a special coating designed to prevent rejection.
Another significant obstacle to transplantation is the shortage of islet cells. Of the 7,000 deceased donors who allow their islet cells to be used, only about half are suitable for transplantation. Researchers are exploring ways to create islet cells from stem cells that could be grown in the laboratory, thereby making an unlimited supply available. But this is probably years from becoming a reality.
Pancreatic Islet Cell Transplantation. National Diabetes Information Clearinghouse. Accessed October 25, 2009. http://diabetes.niddk.nih.gov/dm/pubs/pancreaticislet/