Rheumatoid arthritis (RA) is a chronic, inflammatory condition characterized by joint swelling and tenderness and synovial joint degeneration, which leads to chronic pain, extensive joint damage and severe disability.1 RA is considered an autoimmune disease, and the development and optimal use of disease-modifying antirheumatic drugs (DMARDs) have greatly improved patient management and clinical outcomes. Moreover, early diagnosis and intervention has been shown to reduce the progression of joint damage and disability.
Pathophysiology
Pathophysiology of RA involves complex cellular and molecular interactions between the innate and adaptive immune systems, and the synovium is the primary site of the inflammatory and degenerative processes. Early changes result from non-specific inflammation. In the amplification phase, T cells and B cells are activated, which in turn, activate cytokines and proteases. In the chronic phase of RA, destruction of cartilage and bone is primarily due to interleukin 1 (IL-1), tumor necrosis factor alpha (TNF-α) and IL-6.
Incidence and Related Conditions
RA prevalence estimates range from 0.5–1.0% in Europe and North America; estimates are lower in Asia (0.2–0.3%).
There are genetic (eg, human leukocyte antigen [HLA], protein tyrosine phosphatase [PTP] N22 variant) and non-genetic risk factors (eg, female gender, tobacco, bacterial and viral infection) for RA.
Cardiovascular disease is the leading cause of death among patients with RA, and osteoporosis is a major comorbidity that can result from the disease as well as the use of corticosteroids.
Differential Diagnosis
- Psoriatic arthritis
- Viral-induced arthritis
- Systemic lupus erythematosus
- Mixed connective tissue disease
- Sjögren’s syndrome
- Spondyloarthropathy
- Scleroderma
- Dermatomyositis
Radiographic Findings
In rheumatoid arthritis, typical X-ray findings can include soft tissue swelling, joint space narrowing, periarticular osteoporosis, bone erosions and eventually joint subluxation, dislocation or even auto-arthrodesis in the wrist.
