In what may pave the way for an effective treatment for rheumatoid arthritis, scientists have identified what they claim is a “master switch” which triggers the condition.

A team at Imperial College London has, in fact, found a protein, called IRF5, that acts as a switch, telling immune system cells, called macrophages, to promote or stop inflammation, the ‘Daily Express’ reported.

“This is really exciting,” lead researcher Dr Irina Udalova was quoted as saying.

Rheumatoid arthritis is an incurable immune system disease where joints are swollen by inflammation. The body uses inflammation as a defence against infection and tissue damage, but too much is harmful.

Blocking the production of IRF5 could help in a range of diseases including RA, lupus and even MS, say the British scientists.