RHEUMATOID ARTHRITIS CAUSES

The cause of RA is unknown. While a person’s genetic make-up can predispose them to developing RA (research suggests RA is four times more likely to develop in first degree relatives than in the general public), the most common theory is that RA develops in a susceptible person in response to trigger factors, such as an infectious agent.

It is possible that part of the infectious agent remains in the synovial membrane, generating a chronic inflammatory reaction. Another theory is that the infectious agent’s structure is similar in make-up to the tissue or cell in joint tissue, or that it alters the structure of the tissue so the immune system recognises it as foreign material and attacks the synovial membrane. This is known as an autoimmune reaction.

There are a number of other theories as to the cause of RA including loss of normal self-tolerance leading to inappropriate stimulation of the immune system against parts of the body or breakdown in the mechanisms that control inflammation.