The Science of Rheumatoid Arthritis

Question 1

What are the functions of the synovium?

Answer 1

• maintainance of intact tissue surface
• lubrication of cartilage
• control of synovial fluid volume + composition
• nutrition of chondrocytes within joints

Question 2

What is rheumatoid arthritis?

Answer 2

• chronic symmetric polyarticular inflammatory joint disease- primarily affects small joints in hand and feet
• the rheumatoid synovitis (pannus) has; inflammatory cell infiltration, synoviocyte proliferation + neoangiogenesis
• synovial fluid in joint cavity has neutrophils- especially during acute flares
• synovial pannus causes bone + cartilage destruction (deformities)

Question 3

What autoantibodies are associated with rheumatoid arthritis?

Answer 3

• rheumatoid factor antibodies*
• anti-citrullinated protein antibodies (ACPA)*
• the autoantibodies recognise joint or systemic antibodies and can contribute to inflammation

*seropositive rheumatoid arthritis,
seropositive rheumatoid arthritis poorer prognosis that seronegative rheumatoid arthritis

Question 4

What environmental factors are associated with rheumatoid arthritis?

Answer 4

• smoking + bronchial stress (silicone exposure)
• infectious agents
• viruses, E. coli, mycoplasma, periodontal disease, microbiome
• repeated insults in a genetically susceptible individual

Question 5

What is synovitis?

Answer 5

• villous hyperplasia
• infiltration of; T cells, B cells, macrophages + plasma cells
• intimal cell proliferation (fibroblasts)
• production of cytokines + proteases
• inc. vascularity
• self-amplifying process

Question 6

What are the systemic consequences of rheumatoid arthritis?

Answer 6

• vasculitis, nodules, scleritis, amyloidosis (from uncontrolled chronic inflammation)
• CVS diseass
• fatigue + dec. congnitive function
• dysregulation of HPA axis
• liver disease
• elevated acute phase response
• anaemia of chronic disease
• interstitial lung disease, lung fibrosis
• sarcopoenia
• osteoporosis
• secondary Sjogrens syndrome