Islet cell transplants for Type 1 diabetes

About one third of people with type 1 diabetes each year will experience a ‘severe’ hypo – meaning that they need someone else to help them. Severe hypos can occur in anyone taking insulin, but they are more likely to occur in people who have had diabetes for more than 15 years and those who are unable to recognise when their blood glucose is low (a problem known as hypoglycaemic unawareness). For these people, an islet transplant can be a life-changing, and sometimes a life-saving, therapy.

• People with type 1 diabetes who have experienced two or more severe hypos within the last two years, and have impaired awareness of hypoglycaemia.
• People with type 1 diabetes and a functioning kidney transplant who experience severe hypos and impaired hypoglycaemia awareness or poor blood glucose control despite the best medical therapy.

• People who need a lot of insulin (e.g. more than 50 units per day for a 70kg person).
• People who weigh over 85kg.
• People with poor kidney function.

Islet transplants have been shown to reduce the risk of severe hypos. Results from UK islet transplant patients showed that the frequency of hypos was reduced from 23 per person per year before transplantation to less than one hypo per person per year afterwards.

Islet transplants usually also lead to improved awareness of hypoglycaemia, less variability in blood glucose levels, improved average blood glucose, improved quality of life and reduced fear of hypos. Long-term results are good and are improving all the time. For example, the majority of transplant patients can now expect to have a functioning transplant after six years and some people have had more than 10 years of clinical benefit.

Islet transplants involve a small but increased risk of certain cancers, severe infections and other side effects related to the medication needed to prevent the islets from being rejected by the body (which is the same medication used by people who receive other kinds of transplants).

Islet transplants are unsuitable for people who are desperate to stop their insulin injections. If freedom from insulin injections is achieved, this is usually short-lived, and most people who receive an islet transplant continue to take low-dose insulin therapy. Therefore, islet transplants should not be seen as a cure for diabetes.