Type 1 diabetes is caused by the destruction of insulin-producing cells in the islets of the pancreas. Islet cell transplantation involves extracting islet cells from the pancreas of a deceased donor and implanting them in the liver of someone with type 1.
This minor procedure is usually done twice for each transplant patient, and can be performed with minimal risk using a needle under local anaesthetic.
In 2008, the UK launched the first government-funded islet transplant programme in the world. As of March 2015, 152 islet transplants had been performed in the UK since the launch. Islet cell transplants are now available through the NHS for people who satisfy the criteria given below.
When are islet transplants needed?
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.
Who might not be suitable for an islet transplant?
- 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.
What are the potential benefits?
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.
What risks are involved?
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.
Find out more
If you think you might be eligible for an islet transplant, please read the detailed guide to islet transplants (PDF, 1MB) prepared by the UK Islet Transplant Consortium and discuss it with your diabetes healthcare team.
Who to contact
Referrals for islet transplant are being accepted by teams at seven centres across the UK. The doctors at each centre are very happy to discuss possible referrals and can be contacted directly.