Possible Risks

The risks of islet transplantation can be divided into 1) those associated with the procedure itself, and 2) those associated with immunosuppression. These risks are outlined here.

Significant experience has been gained in the 15 years since the program launched and currently the procedure is safer than it has ever been. We have also become skilled at tailoring the immunosuppressant drugs to the needs of the individual to minimize side effects.

Islet transplant procedure

  1. Bleeding from the liver. This can result from the needle poke where the catheter is inserted into the liver. In some cases this has required a blood transfusion. In order to make your islet transplant safer, and to reduce the chance of bleeding we ask our patients to stop taking ASA (aspirin), either as long-term protection against heart disease or short-term as a cold remedy/pain killer. In addition we use a special collagen paste to seal up the whole in the liver at the end of the transplant.
  2. Blood clot in a portal vein. Small clots in a branch of the portal vein may result from the infusion of islets into the portal vein. To detect small clots we routinely perform ultrasound scans one day and one week after transplant. Small clots have been successfully treated with a 3-6 month course of blood thinning medication.  If the entire vein developed a clot, this could lead to liver failure and potentially to risk of death or need for liver transplantation.
  3. An allergic reaction to the dye used to locate the portal vein.
  4. Infection carried with the islets.
  5. Shoulder and abdominal pain. Usually resolves within 2-3 days.
  6. Fat deposition around the islets in the liver has been seen on follow-up scans in 20% of patients. The significance of this is not known.

Immunosuppressive drugs
You will be on these drugs for as long as the islet tissue is functioning. They prevent your body from rejecting the islet tissue.

  1. Increased risk of infection due to suppression of your immune system. Infections are usually viral in nature and resolve with time. Sometimes the infection may be very serious. Serious infections have been experienced by approximately 2% of recipients.
  2. The antirejection drugs all carry a small risk of increased incidence of certain kinds of cancer. These risks are not fully known at present for the antirejection drug combinations used in the Clinical Islet Transplant Program in Edmonton. The estimated risk of post transplant lymphoproliferative disorder (PTLD) is of the order of 1%. The incidence of certain skin cancers and the risk of cancer (overall about 10-15%), may be slightly higher than the general population. Over 10 years, in 110 patients, we have not seen any cases of PTLD, or deaths from cancer.
  3. Gastric upset, nausea, constipation or diarrhea.
  4. Elevated cholesterol.
  5. Decreased renal function.
  6. There is no information on daclizumab and sirolimus in pregnancy. It is therefore recommended that women complete their family before considering islet transplantation and they must not get pregnant while on these medications. Also, it is recommended that males do not impregnate someone while taking these medications.
  7. Fatigue.

Complications of diabetes 

The rapid stabilization of glucose levels during the first year following an islet transplant may be associated with progression of eye disease, particularly in people who have had laser treatment or surgery for diabetic retinopathy. Our preliminary data from those who have received islet transplants indicates an 8% risk. Because of this risk, the back of your eyes will be checked every three months during the first year and annually thereafter to identify these possible changes early on. You will be required to see an ophthalmologist (eye specialist) yearly for assessment of eye disease.

Immune problems from the islet graft (sensitization)
Transplantation of human islets from another person could lead to the development of antibodies against the proteins (antigens) on the islet tissue. These antibodies will create memory against these antigens and mark them for destruction. This memory could increase the difficulty of obtaining another transplant at a later date because the immune response will be much quicker the next time these antigens are seen by the immune system. This creates less likelihood for successful renal and/or other organ transplants.