An islet cell is an insulin producing cell that lives in the pancreas. Transplanting islet cells to individuals with Type 1 diabetes can provide the ability for their bodies to produce insulin. It is a step in the search for a functional cure for diabetes.
In the United States, islet cell transplantation is only available via research studies. One of the leading research projects in the country is centered at the University of Illinois at Chicago. The program there is known as the Chicago Project, headed by Dr. Jose Oberholzer.
Hypoglycemia Unawareness
The procedure is available to persons aged 18 to 65. The candidate for this research must have hypoglycemia unawareness. In hypoglycemia unawareness, the person’s blood sugar drops to a level where the person may know they need help, but is physically unable to help himself. Without intervention death could occur.
In research programs offering islet cell transplantation, candidates for the procedure are screened very carefully. Once the candidate has met all of the inclusion criteria, and none of the exclusion criteria, they may be listed for an islet cell transplant.
The Process of Islet Cell Transplantation
Once a pancreas of the appropriate blood and tissue type becomes available the transplant candidate is notified by the research center and needs to be at the hospital within a few hours to begin transplant preparation.
Meanwhile, an organ (pancreas) that has been donated from a recently deceased donor is brought into a special laboratory in that the lab is 100 times cleaner than the standard operating room. The pancreas undergoes a mechanism known as digestion. This process allows the release of the insulin producing islet cells. After the cells are isolated, they undergo quality testing for purity and viability. Once this is demonstrated, they are ready for transplantation into the body of the type I diabetic candidate.
The transplantation itself occurs in radiology. The diabetic is awake. A physician with special training in interventional radiology begins the procedure. The candidate’s right upper abdomen just beneath the rib cage is anesthetized. The radiologist then inserts a tiny flexible tube, known as a cannula into the portal vein of the liver.
Once the radiologist has ensured that the cannula is properly positioned the transplant surgeon is notified. The surgeon then brings the isolated islets to the radiology suite where he or she inserts them via the cannula into the person’s portal vein.
The blood flow in this area is very good and is thought to help the islets survive. The liver typically responds well. This procedure takes approximately 45 minutes. The patient is then brought back to a nursing unit where he is monitored carefully for a minimum of 24 hours.
Immediately after the transplant the recipient of the islet cells continues to receive insulin to allow the newly transplanted islets to rest. The person will gradually be weaned from insulin injections and ideally the transplanted islets will begin to function to control the person’s blood sugar. The goal is to have the person relieved from the need to take insulin.
Need for Immunosuppressant Drugs
Because the transplant came from another person, the diabetic’s body would reject the islet cells without immunosuppressant drugs. The requirement for these drugs is a major drawback in the mind of many diabetics. They weigh the value of trading daily insulin injections for daily consumption of immunosuppressant drugs. That is why this procedure is only available to people who fear death because of episodes of hypoglycemia unawareness.
For those diabetics who go to bed without knowing if they will awake because of an episode of hypoglycemia unawareness, the side effects of immunosuppressant drugs are worth the risks.
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