Scientists have taken a step closer to developing a new therapy for people affected by rheumatoid arthritis (RA).

RA is a chronic and often painful condition that affects the joints, causing them to become inflamed. The condition, which can have a major impact on quality of life, affects an estimated 350 million people worldwide, including around 40,000 in Ireland.

While many presume this to be a disease that affects older people, onset usually occurs between the ages of 35 and 45, and children can also be affected. There is currently no cure.

However, a team of scientists led by Dr Achilleas Floudas and Prof Ursula Fearon from Trinity College Dublin (TCD), have pinpointed two new potential therapeutic targets for RA.

These involve 'B cells', which are key cells of the immune system. They are responsible for the production of antibodies that fight infections. With RA, these B cells "fail to recognise friend from foe and thus attack the joints", the researchers noted.

The reasons for this are not fully understood. However the scientists have discovered a new cell population that appears to be particularly troublesome in people with RA. They have also learned how these troublesome cells accumulate in joints.

"We discovered a novel population of B cells in the joints of patients with RA, and these cells are more inflammatory and invasive than those we knew before.

"Their damaging effects rely on the production of specific coded messages, in the form of proteins called cytokines and energy pathways within the cells, which essentially maintain their activation. Basically, they ‘switch on', cause inflammation, and are maintained within the environment of the inflamed joint," Dr Floudas explained.

He said that the scientists had also discovered a new mechanism by which these B cells accumulate in the joint, "by pinpointing the protein that seems to be responsible for attracting them to the joints".

"As a result, we now have two new potential targets for people living with RA. We are some way away from a therapeutic solution, but if we can find a way of targeting these B cells and/or the protein that attracts them to the joints, we can one day hope to develop a therapy that could impact positively on millions of people living with RA," he noted.

This research was funded by the Health Research Board and Arthritis Ireland. Details are published in the journal, JCI Insight.

For more information on RA, click here.