Joint Pathology Flashcards
What type of collagen does articular cartilage contain?
II
At what time during the day is the pain of OA at its worse?
At hte end of the day, after prolonged use
What other body systems can be affected by RA?
Skin
Blood vessels
Heart
Lungs
What might you observe in OA joints?
Reduced ROM
Crepitus (grinding)
Osteophytes
What is fibrillation of cartilage?
Where the surface of cartilage has a shredded appearance due to damage
Describe the pathogenesis of OA?
There is some injury to the joint stimulating chondrocyte proliferation, enzyme/cytokine activity and matrix depletion >
The cartilage matrix begins to unravel with release of enzymes and collagenases and loss of mechanical function >
Thickening of bone and microfractures >
Shredding of cartilage > Fibrillations and erosion >
Bone on bone > erosion, cysts, osteophytes
When in the day are joint symptoms of RA the worse?
Morning > they ease off with activity
What are the immune mediators of RA?
Th-1 and Th-17
- IL-1, IL-6, IL-17, TNFalpha
B cells (plasma cells)
Macrophages
Does too much uric acid always present as gout?
No, it’s asymptomatic at first; for up to 20-30 years
Why isn’t serum urate a good diagnostic for gout?
It is lower during attacks due to urate precipitating
Urate-lowering therapy can precipitating gout
Must people with high urate don’t have gout
What are some systemic signs of RA?
Fever
Anaemia
Weight loss
What do you see histologically in RA?
Mononuclear cell infiltration
Villous hyperplasia
Germinal centres
What is tophaceous gout?
The chronic form of gout with involvement of
- Multiple joints
- Recurrent joint inflammation causing damage
- Urate deposition as tophi
- Gouty nephropathy and kidney stones
What is podagra?
Gout in the big toe
What is the gold standard for gout diagnosis?
Joint aspirate of crystals with neutrophils
Describe the appearance/texture of RA joints?
Doughy
How do you diagnose RA?
CRP, ESR, FBE for inflammation
Rheumatoid factor
Anti-cyclic citrullinated peptide (anti-CCP)
What is the pathological process that leads to RA?
Inflammatory response against arthritogenic antigen >
Mononuclear cells infiltration with germinal centres >
Hyperplasia of synovial membrane > villous formation >
Pannus formation (granulation tissue) >
Neutrophil and fibrin may enter >
Pannus invades and erodes bone and cartilage >
Weakening of ligaments >
Union of bone
How do RA joints appear on x-rays at the end stage of the disease?
Subchondral erosion
Uniform joint space loss
What are the symptoms of gout?
Spontaneous onset of excruciating pain, heat, redness and swelling
What must occur at the joint for perfusion of articular cartilage to occur?
Compression and decompression of the cartilage
Which joint pathology has punched out overhanging edges?
Gout
What do subchondral cysts contain?
Synovial fluid
How do tophi appear histologically?
Granulomatous inflammation (foreign body type)
- Epithelioid macrophages
- Multi-nucleated giant cells
- Central urate crystal deposites
What are the types of cells that make up the synovial membrane?
Type A - Macrophage like
Type B - Fibroblast like
What are the three histological features of OA?
Subchondral thickening
Osteophytes
Non-uniform loss of cartilage
Why do you get neutrophil lysis with gout?
Urate cystals pierce the neutrophil membrane
What is added to synovial fluid to increase its lubricating ability?
Hyaluronic acid
How much do genetics contribute to risk of developing RA?
50%
How do rheumatoid nodules appear histologically?
Granulomatous inflammation
- Central necrosis
- Epithelioid macrophages
- Lymphocytes and fibroblasts surrounding
