Scientists have discovered a new protein that regulates the severity of tissue damage in people with RA.

The study of DNA and biopsy samples from joints of over 1,000 rheumatoid arthritis patients found the protein C5orf30 was highly expressed in the synovium of RA patients compared with control synovial tissue.

It was predominately expressed by synovial fibroblast (RASF) and macrophages in the lining and sublining layer of the tissue.

“These cells play a central role in the initiation and perpetuation of RA and are implicated in cartilage destruction,” wrote the researchers from University College Dublin and the University of Sheffield in this week’s PNAS.

“Our findings provide a genetic marker that could be used to identify those RA patients who require more aggressive treatments or personalised medicine,” said lead author Professor Gerry Wilson from the UCD School of Medicine and Medical Science, University College Dublin.

“They also point to the possibility that increasing the levels of C5orf30 in the joints might be a novel method of reducing tissue damage caused by RA”.