Heart transplant research

Organ transplant surgery

Rejection of the donor heart is a common complication for heart transplant patients. Dr Wilson Wong hopes to find out more about why this happens. He talks to Doireann Maddock.

More than 750,000 people in the UK are living with heart failure and there is no cure. For some of these people, heart transplantation is their best option. There are between 120 and 165 heart transplants in the UK each year but rejection of the donor heart is a common, and potentially fatal, complication. Scientists such as Dr Wilson Wong hope to reveal new ways of protecting donor hearts from rejection so that in the future transplanted hearts can survive longer.

Why is this research necessary?

Rejection is the most common cause of the donor heart failing in heart transplant patients. If the transplanted heart fails, the patient dies. We know the lymphatic system plays a critical part in the body’s immune response. It is this immune response that causes rejection.

The better we understand the rejection process, the better we will be able to design new treatments to help prevent it

However, the lymphatic system after organ transplantation hasn’t been well studied. This is one of the reasons I’m interested in studying this area. The better we understand the rejection process, the better we will be able to design new treatments or therapies to help prevent it.

Can you explain what exactly the lymphatic system does?

The lymphatic system is a part of the immune system. It is a network of thin tubes that runs throughout the body acting as a second circulation.

The tubes branch throughout the body like the arteries and veins that carry blood, but the lymphatic system tubes carry colourless liquid called lymph. Lymph contains a high number of white blood cells and is one of the factors that help our bodies fight off infections.

During heart transplant surgery, the donor arteries and veins are attached to their corresponding parts in the person receiving the heart. However, the lymphatic vessels of the donor heart are not surgically reconnected (it would make the surgery even more complicated and lengthy). This is one reason I’m interested in this area.

Why does rejection happen?

The recipient’s body sees the donor heart as foreign, so it is rejected by their immune system in the same way that we fight off an infection. The lymphatic system plays an important role in the rejection process.

Heart transplant patients therefore need to take a number of different immunosuppressant (anti-rejection) medicines for the rest of their lives. Unfortunately, they can have serious side effects such as increasing the risk of infection, kidney failure and certain cancers.

What will your research involve?

Success would mean obtaining enough information to secure funding for further parts of this research

We’ll use a special body scanner, like a CT scan but with additional features, to study how the lymphatic system develops and works in mice that have had a heart transplant. This will help provide basic information about the post-transplant lymphatic system.

We will test various ways of stopping the lymphatic system growing, looking at how the lymphatic flow changes after transplant and to see whether the immune response affects it.

This part of our research is expected to take 12 months –we hope to use findings from this stage to secure further funding to develop ways to influence the lymphatic system that can be applied to recipients of donor hearts.

What would success look like?

Success would mean obtaining enough information to secure funding for further parts of this research. This may help to reveal new ways in which the lymphatic system can be modified in order to help combat rejection and reduce the need for current long-term immunosuppressant drugs.

BHF research fact file

Funds awarded by the BHF: £139,824

BHF grant awarded to: Dr Wilson Wong, King’s College London

Project summary: The lymphatic system in cardiac transplantation, looking for new ways to protect heart transplants from rejection

Dr Wilson WongDr Wilson Wong

Dr Wilson Wong is Reader in Transplant Immunology at King’s College London. He is also an Honorary Consultant Nephrologist at Guy’s and St Thomas’ hospitals. He has a long-standing interest in organ transplantation.

More useful information