18th January 2024

Background

Epidemiology

Rheumatoid Arthritis (RA) is the commonest inflammatory arthritis in the United Kingdom (UK), affecting approximately 1% of the population. The incidence of RA is greater in smokers, and it is also between 2-4 times more common in females. RA can occur at any age but peaks between the ages of 30-50 years.

Pathophysiology

RA is a chronic, systemic autoimmune disease primarily affecting the lining of synovial joints. The deformities typically associated with RA occur due to the stretching of tendons and ligaments and destruction of joints through the erosion of cartilage and bone.

A combination of genetic and environmental factors can be responsible for triggering RA. Inherited genes in the human leukocyte antigen (HLA) major histocompatibility complex (MHC) are of particular importance. The presence of HLA DR4/DR1 in RA patients is associated with increased disease severity. Smoking is the best-defined environmental stimulus, likely due to repeated activation of innate immunity, especially at mucosal surfaces.

References

• Guo Q, Wang Y, Xu D, Nossent J, Pavlos N, Xu J. Rheumatoid arthritis: pathological mechanisms and modern pharmacologic therapies. Bone Research. 2018;6(1).
• Rheumatoid arthritis | Health topics A to Z | CKS | NICE [Internet]. Cks.nice.org.uk. 2021 [cited 10 November 2021]. Available from: https://cks.nice.org.uk/topics/rheumatoid-arthritis/
• UpToDate [Internet]. Uptodate.com. 2021 [cited 10 November 2021]. Available from: https://www.uptodate.com/contents/pathogenesis-of-rheumatoid-arthritis?search=rheumatoid%20arthritis&source=search_result&selectedTitle=8~150&usage_type=default&display_rank=8#H3