Islet transplantation involves taking the insulin-producing cells of an organ donor’s pancreas and infusing them into a recipient with type 1 diabetes. The insulin-producing cells are found in the normal pancreas in clusters termed islets. Because the donor and recipient tissues have small but important differences the transplanted islets will be destroyed (“rejected”) by the immune system as “foreign” if immunosuppressive drugs are not taken continuously by the recipient. This is true of any tissue transplanted from one individual to another unless they are identical twins.
Islet transplantation can return blood glucose to normal levels – which is not surprising because we are restoring what type 1 diabetes has destroyed. Donor islet tissue is in short supply and this, coupled with the risks of immunosuppressive drugs, means that islet transplantation is only used at present in a small sub-set of patients with type 1 diabetes. These are people with severe and problematic hypoglycemia. Islet transplantation is remarkably and rapidly successful in stopping problematic hypoglycemia. This is true whether or not (roughly 50:50) you need to keep taking insulin after your transplant.
If you have type 1 diabetes and are interested in the possibility of an islet transplant and would like to find out if your problem with hypoglycemia is severe enough for you to be eligible then we would welcome an inquiry from you. This normally works by your endocrinologist referring you to our Islet Transplant Clinic where you will be assessed by a multi-disciplinary team that includes diabetes specialist, transplant specialists and others.
The assessment period involves clinical assessment and some blood tests and other fairly simple tests. It also involves working out how often you are experiencing hypoglycemia and how severe it is. One of the important measures of severity is how “aware” you are that your blood glucose is low – hypoglycemia awareness can be reduced after years of diabetes and this increases the risks of hypoglycemia because you might not take steps to reverse it.
If you are assessed as suitable then you will join the waiting list for a transplant. Transplants are carried out in hospital in the Radiology Department by putting a plastic tube (a cannula) into the portal vein, a large vein in the liver. This is in general a safe procedure although complications can arise that we will tell you about when we meet. After the transplant you stay in hospital for a few days and then are followed up as an outpatient and must continue to take your anti-rejection pills indefinitely. Many people have more than one islet transplant procedure.
Of course there are many other details and we will talk to you about these face-to-face and more technical details are also available on the page for clinicians. We will also be very happy to answer any questions you have when we see you.