Overview of rheumatoid arthritis
Rheumatoid arthritis (RA) is a chronic autoimmune disease characterised by persistent synovitis and polyarthritis, systemic inflammation and the presence of autoantibodies. It may be associated with multiple extra-articular features, most commonly rheumatoid nodules, and secondary Sjögren syndrome1.
The pathophysiology of RA involves various cytokines, effector cells and signalling pathways; tumour necrosis factor, interleukin-6 and interleukin-1 appear to be the key cytokine mediators of the disease process.
The prevalence of RA is about 1%, with females more commonly affected than malesMyasoedova, 2010. The risk of developing RA is influenced by both genetic and environmental factors. Inheritance is not strong, with multiple genes involved, but there is approximately 15% concordance in identical twinsMacGregor, 2000Silman, 1993. The most established genetic link is the human leucocyte antigen DR4 (HLA-DR4).
Avoiding tobacco smoking and maintaining ideal body weight by exercising and eating a healthy diet, decreases the likelihood of developing RAOliver, 2006.
Although RA can cause significant morbidity and mortality, the prognosis is very good for most people when they are referred to a specialist and treated early with disease-modifying antirheumatic drugs (DMARDs). The prognosis for people with RA has substantially improved in the last 20 years because of the early use of DMARDs and focus on optimal management of disease activityBakker, 2007Jacobs, 2012.