Islet transplants

What are islets?

Islets, short for islets of Langerhans, are clusters of cells in the pancreas. Islets contain the insulin-producing beta cells, which are destroyed in type 1 diabetes. They also contain cells that release other hormones, like glucagon.

What is an islet transplant?

An islet transplant involves transplanting islets from organ donor pancreases into people with type 1 to give them a new supply of insulin-producing beta cells. People often stop needing to take insulin after an islet transplant, then gradually start needing insulin injections again as their body destroys the new beta cells.

Who can have an islet transplant?

People who are really struggling to manage their type 1 and have hypoglycaemia (hypo) unawareness may benefit from insulin transplants. Hypo unawareness is a condition where someone with type 1 gets no warning that their blood glucose levels are falling.

If other glucose management strategies don’t work, such as using a continuous glucose monitor or an insulin pump, an islet transplant may be the best option. In the UK, islet transplants are offered by the NHS to people who need them.

Why can’t everyone have an islet transplant?

Islet transplants may sound like a straight-forward way to treat type 1 diabetes, but they are not a routine treatment for type 1 because the benefits usually do not outweigh the risks.

Risks from immunosuppressants

People who have had islet transplants need to take powerful immunosuppressant drugs to help stop the immune system attacking the new cells. These drugs can mean the body can’t fight off simple infections, making you more vulnerable to serious illness.

Shortage of organ donors

Several organ donors are needed to get enough islets for a transplant for a single person with type 1. Immunosuppressant drugs can only protect these new islets for a few years before the immune system destroys them. So, people receiving islet transplants need new islets every few years. Because so many donors are needed to allow just one person to continue receiving islet transplants to treat their type 1, there are not enough donors for everyone.

Research to improve islet transplants

Together with the Medical Research Council, we are funding a healthcare professional called Daniel Doherty to complete a PhD. In his PhD project, Daniel will aim to make islet transplants a better treatment for people with type 1 by making them work more effectively for longer.

We are also funding research to improve islet transplants through the Type 1 Diabetes Grand Challenge our partnership with Diabetes UK and the Steve Morgan Foundation. We are funding Professor Shareen Forbes and Dr Lisa White’s project to develop drugs that can be transplanted alongside islets to keep them healthy and protect them from the immune system so that they can survive for longer.