3-Articular Pathology

Question 1

Matrix metalloproteinase substrates include?

Answer 1

Collagen and gelatin, elastin, proteoglycans, matrix glycoproteins

Question 2

What is Cathepsin K?

Answer 2

Cysteine protease highly expressed in osteoclasts, most active at acidic pH (the lacunae are acidic). Active against type 1 collagen.

Question 3

Describe rheumatoid arthritis

Answer 3

Chronic autoimmune disease characterised by pain, stiffness and symmetrical synovitis of synovial joints

Question 4

Name the key features of rheumatoid arthritis

Answer 4

Chronic arthritis - polyarthritis, symmetrical, early morning stiffness (rest makes joint worse), joint erosions
Extra articular disease - nodules
Rheumatoid factor may be detected in blood - IgM antibody against IgG

Question 5

Describe the swan-neck deformity

Answer 5

Hyper-extended PIP, hyper-flexed DIP

Question 6

Describe the Boutonniere deformity

Answer 6

Hyper-flexed PIP

Question 7

What is ACPA or anti-CCP?

Answer 7

Antibodies to citrullinated protein antigens - highly specific for rheumatoid arthritis

Question 8

Which cytokine has the biggest role in rheumatoid arthritis?

Answer 8

TNF-alpha

Question 9

Describe the role of TNF-alpha in rheumatoid arthritis

Answer 9

Main pro-inflammatory cytokine. Causes the release of further pro-inflammatory cytokines in the synovium, (prostaglandin-causes fever and vasodilatation), osteoclast activation, chondrocyte activation and MMP release, leukocyte migration and activation

Question 10

Describe treatments for rheumatoid arthritis

Answer 10

TNF-alpha inhibition - fusion proteins or antibodies
IL-1 and IL-6
Anti CD20 antibodies to deplete B cells
OPG (osteoprotegerin) - decoy receptor for RANKL
DMARDS - reduce inflammation and joint damage