Islet Cell Transplants
Many people with diabetes already know about the importance of islet cells, and how important these pancreatic cells are in determining whether a person is diagnosed with diabetes and what type of diabetes they have.
Islets are cell groups within the pancreas which are comprised of beta cells - the cells that make insulin, the hormone that regulates blood glucose levels.
Recent advances in medical science have allowed islet transplantation – replacement of destroyed beta cells using cells harvested from donors.
Islet cells and diabetes
Amongst people with type 1 diabetes, pancreatic beta cells are destroyed. This means that regular insulin delivery (via injections or an insulin pump) is the only way to stay healthy.
For some people with type 1 diabetes, it is very difficult to achieve and maintain stable blood sugar levels.
Islet cell transplants vs pancreas transplants
Islet transplants are a safer option than pancreas transplants.
Islet transplantation is safer because if the body rejects the transplant, it is better for the body to reject a part of the organ, the islet cells, than the entire organ, the pancreas, as the pancreas performs more functions than just insulin production.
A further reason for why islet cell transplantation is safer is that it is a less critical operation to insert islet cells than it is transplant a complete pancreas.
Islet cells that the pancreas has destroyed are replaced using cells from donor pancreases.
How do islet cell transplants work?
Usually, transplant patients are given islet cells from as many as three donor pancreases. Just like healthy pancreatic beta cells, the donor cells produce insulin in a normal way. This can help to achieve blood glucose stability and lower the amount of insulin required.
Furthermore, in some cases, beta cell transplants may be so effective that the patient receiving transplants can stop insulin administration entirely.
Are islet cell transplants a new thing in the UK?
Islet cell transplantation procedures remain rare in the UK since their origins in 2000 in Canada. Leading diabetes charity Diabetes UK set up the Islet Cell Consortium in the UK, bringing together nine different islet research centres. Diabetes UK also raised money to pay for the first ten islet transplantations in the UK, based on the work done in Canada.
So far, Diabetes UK has secured funding for another five transplants, all of which have been carried out at centres in London and Oxford. Nine of the fifteen operations conducted to date have been successful.
So will islet cell transplantation become more widespread?
Islet cell transplantation is experimental at this stage, and there are no guarantees of its efficiency in letting patients live without insulin. Unfortunately, the pancreas will reject foreign islet cells without drug treatment. The drugs required to guarantee cell acceptance may lead to serious side effects.
So who gets an islet cell transplant?
At this stage, the procedure is only considered suitable for individuals who cannot control their diabetes, experience dangerous levels of hypos and face a dramatically lower quality of life. In these situations, islet cell transplants may be considered.
Has it worked?
So far, one UK patient was able to come off insulin entirely for about a year.
All other patients in the trial lowered their insulin dose, removed the risk of hypoglycemia, improved blood glucose control and improved their quality of life.
All trial patients have been able to return to a normal lifestyle without the threat of major hypoglycemia.
So I could stop taking insulin entirely with an islet cell transplant?
Although people may be able to entirely stop taking insulin, transplanted islets are supported with a small insulin dose to maintain their health. As well as the anti-rejection drugs, patients take a small dose of insulin for this reason.