Immune cells 'play a role in increasing heart disease risk for people with lupus'
Published on 07 December 2016
The elevated risk of heart disease experienced by people with lupus may be predicted by the way certain immune cells function, according to a new study.
Funded by Arthritis Research UK and led by University College London, the study has revealed how a specific type of immune cell tries to dampen down the development of atherosclerosis, offering a new insight that could aid the diagnosis and treatment of heart disease in lupus patients.
How iNKT cells can cause atherosclerosis for lupus patients
It is well-established that people with lupus generally have higher rates of atherosclerosis, a condition characterised by the buildup of fatty material lining the artery wall. This blocks the arteries and can lead to events such as heart attacks.
The new research, which involved 100 patients with lupus, aimed to examine the role played by invariant natural killer T (iNKT) cells in this process. This type of immune cell is associated with the development of atherosclerosis, while also behaving defectively in people with autoimmune diseases such as lupus.
Results published in the medical journal Science Immunology revealed that 36 per cent of people with lupus had plaques, showing they were experiencing the beginning stages of atherosclerosis. Those with plaques had a greater number of iNKT cells, which were unusually active and showed significant anti-inflammatory activity compared to those in people without plaques.
People with plaques were also shown to have different levels of fats in their blood that correlated to how active the iNKT cells were, suggesting the fats may be activating the immune cells. The team believes that these immune cells are activated early in the atherosclerosis process to keep the plaque in check, but, over time, the cells become inactive. This allows heart disease to progress, leading to serious cardiovascular events.
Improving treatment in future
The findings of this study will help scientists to better understand the link between blood composition, immune cell activation and heart disease in future. This could be an important step forward, as this knowledge could make it easier to predict when lupus patients are at risk of heart disease, allowing doctors to provide treatment as soon as possible.
The researchers concluded: "In summary, we show that iNKT cells could play a key role in linking the immune system, lipids and cardiovascular disease in patients with lupus. This supports the development of new diagnostic and therapeutic targets for patients at increased cardiovascular risk."
The experts' view
Dr Elizabeth Jury at the University College London, who participated in this study, said: "A close collaboration between scientists and clinician scientists has led to the identification of potential new markers to predict lupus patients at increased cardiovascular risk, advancing our knowledge about human atherogenesis mechanisms in autoimmunity.
"We are continuing this work in lupus patients and also trying to find out whether we can use similar measures in other at risk groups, including patients with rheumatoid arthritis."
Natalie Carter, head of research liaison and evaluation at Arthritis Research UK, added: "Lupus is a complex autoimmune condition that causes the immune system to attack the body's own tissues. We know that people with lupus are often at increased risk of developing other health conditions, including heart disease.
"This study shows that it may be possible to predict the progression and severity of atherosclerosis in lupus, which could play a vital role in the prevention and treatment of the condition. This new insight will help us in planning the right services for people with lupus who are at a greater risk of heart disease, so that they can be closely monitored and supported by their healthcare professionals, ensuring prompt and effective treatment."