The Science of Rheumatoid Arthritis Flashcards
The two ends of bones coming together to make a joint are lined with what?
Articular cartilage
Functions of synovium?
Lubrication of cartilage
Control of synovial fluid volume
Nutrition of chondrocytes within joints
Maintenance of intact tissue surface
How does the synovium link to rheumatoid arthritis?
Synovitis is hallmark of rheumatoid arthritis
Cells in lining of synovium?
Macrophages
Fibroblasts- maintenance of lubrication
What happens to a joint affected by rheumatoid arthritis?
Thickening of synovium due to inflammation aka synovitis
What effect does synovitis have on bone and cartilage?
Causes erosion
Rheumatoid arthritis?
Chronic symmetric polyarticular inflammatory joint disease
(say that five times fast)
In rheumatoid arthritis, what is the synovitis characterised by?
Inflammatory cell infiltration, fibroblast proliferation and neoangiogenesis
Rheumatoid arthritis is an autoimmune disease.
What can be associated with rheumatoid arthritis?
Autoantibodies e.g. rheumatoid factor and anti-citrullinated protein antibodies
->these autoantibodies can contribute to inflammation
Which autoantibodies are usually checked for?
ACP antibodies- more specific
Rheumatoid factor
What does rheumatoid factor recognise of self?
IgG
->so recognises it as mot being part of ourselves I think so tries to destroy
Genetics play a part in the pathogenesis of rheumatoid arthritis, what are some of the environmental factors
?
Smoking
Infectious agents e.g. E.Coli
What process occurs in the ACP antibodies response in rheumatoid arthritis?
Citrullination
What happens in citrullination?
Conversion of arginine (amino acid) into citrulline (another amino acid)
What enzyme is responsible for the conversion of arginine into citrulline?
Peptidylarginine deiminases (PADs)
What is the pathological hallmark of RA>
Synovitis
What is synovitis characterised by?
Intima hyperplasia with infiltration of mononuclear cells e.g. CD4+ T cells, macrophages and B cells
Describe what happens in synovitis.
Villous hypertrophy
Infiltration of T cells, B cells and macrophages
Intimal cell proliferation
Production of cytokines and proteases
Increases vascularity
What do inflammatory cytokines activate?
Synovial fibroblasts
Chondrocytes
Osteoclasts
Neoangiogenesis?
Production of new blood vessels
->occurs in synovitis as provides nutrients to hyperplastic synovium
What does the destruction of cartilage and bone cause?
Joint space narrowing and erosions
Which cells mediate bone destruction?
Osteoclasts
What are the key cytokines in chronic inflammatory arthirits?
TNF-alpha
IL-1
IL-6
RANK-ligand
IL-17
Systemic consequences of rheumatoid arthritis?
CVD
Fatigue
Liver
Lungs
Muscles- sarcopenia
Bone- osteoporosis
Secondary Sjogren’s syndrome
