Improving response to vaccines and infection in immunosuppressed patients
Infections in patients with a kidney transplant remain a serious challenge
People with kidney transplants are all too familiar with the downsides to the immunosuppressants they need to stop their immune system from rejecting their new kidney. Transplant recipients are particularly vulnerable to infections caused by viruses and because immunosuppressed people often also respond poorly to vaccinations, they are more likely to have severe symptoms if they contract viruses such as Covid-19.
Professor Ian Humphreys is lead co-director of the Systems Immunity Research Institute. He comments: “It is crucially important that patients take anti-rejection drugs as prescribed by their doctor, but this type of medication can make them more vulnerable to serious infections. The Covid-19 pandemic has shown us how important it is to ensure we can offer protection against infectious disease for everyone, even when their immune response is weakened.”
Meet Professor Ian Humphreys
Professor Humphreys works at the University of Cardiff. The studentship grant of £75,000 co-funded by Kidney Research UK and Kidney Wales will enable his team to support a student through their PhD studies, while contributing valuable information to support kidney patients.
He received a grant in our November 2022 round to investigate nutritional amino acid regulation of antiviral immunity in kidney transplant patients.
Understanding the immune response in transplant patients
T cells and natural killer (NK) cells are parts of the immune system that help to protect the body from infection by viruses. These cells have nutritional needs including amino acids, which are the building blocks of proteins. One amino acid, called L-arginine, is particularly important for T cell health. Previous work has shown that kidney transplant patients’ reduced ability to control viral infections may be due in part to a lack of L-arginine for their T cells, and possibly NK cells too.
Professor Humphreys explains: “This is potentially an easy-to-fix problem, as L-arginine dietary supplements are readily available. With the support of this grant, we will undertake the science to find out if this is an effective approach.”
What is L-arginine and why is it important?
Found in most protein-rich foods and available as a nutritional supplement, L-arginine promotes the ability of T-cells to expand in numbers in response to infection and supports the development of long-lasting immune protection through a type of T cell called a ‘memory cell’.
Kirsty Clarke, transplant recipient
“As a kidney transplant recipient, I feel incredibly fortunate to have been given my life back. However, my immunosuppression means I am always fearful of doing the things I love due to the risk of infection. It's like undertaking a full risk assessment before I go out and, in some cases, deciding that the risk is too great.
This research is critical to see if there are other ways to help our immune systems protect us. If successful, this will not only improve our quality of life but in some cases will be life-saving.”
Looking for future treatment options
Professor Humphreys will study how L-arginine affects the immune responses in kidney transplant patients, either during viral infection or following vaccinations for Covid-19. He will also look at whether immune cells from transplant patients can be encouraged to respond to viruses by increasing their access to L-arginine. This study could lead to a cheap and simple approach to help protect kidney transplant patients from viruses.
*This is an experimental study. Please consult your doctor before taking any non-prescribed treatments or supplements.
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