Inflammatory Joint Disease

Question 1

Rheumatoid arthritis is an autoimmune disorder primarily involving joints. Most patients have at least one other site of involvement. What are the three most common?

Answer 1

Skin
Lung
Heart

Question 2

Which gene is linked to rheumatoid arthritis?
Does it mean the patient has RA?

Answer 2

HLA-DR4
75% of RA patients are HLA-DR4 positive - not all.

Question 3

Describe rheumatoid factor as a diagnostic marker for RA?

Answer 3

RA patient have raised serum IG, and an antibody against called rheumatoid factor.

However it is not a definitive diagnostic marker

Not everyone who is RF positive has RA and vice versa.

Question 4

Four stages of rheumatoid arthritis pathogenesis?

Answer 4

1. Triggering stage
   * Anti-citrullinated peptide antibodies (ACPA) production
2. Maturation stages
   * Citrullinated of proteins activates T cells and B cells = more ACPA production
3. Targeting stage

• Involvement of joints
• Synovitis and joint swelling

4. Fulminant stage

• Synovival hyperplasia
• Bone and cartilage destruction
• Ankylosis (fibrous fusion)

Question 5

Clinical presentation of RA

Answer 5

• Localised joint symptoms
• Radial deviation of wrist, ulnar deviation of fingers - swan-neck and boutonniere deformities
• Fatigue, malaise, MSK pain

Question 6

Pathological findings in joints in RA?

Answer 6

Inflammatory infiltrate

Fibrous ankylosis

Angiogenesis

Oedematous, thickened synovium

Question 7

Compare serum antibodies in osteoarthritis vs rheumatoid arthritis

Answer 7

Osteoarthritis doesn’t involve serum antibodes.

RA has ACPA and rheumatoid factor.

Question 8

Compare the joints involved in osteoarthritis vs RA

Answer 8

Osteoarthritis affects the weight bearing joints such as hips and knees.

Rheumatoid arthritis typically begins with small joints of fingers (MCP and PIP joints)

Question 9

What is reactive arthritis?

Answer 9

Post-infection arthritis - after genitourinary (Chlamydia) or GI infection (shigella/salmonella)