Rheumatoid Arthiritis

Question 1

Define rheumatoid arthiritis and its key features

Answer 1

Chronic autoimmune disease characterised by pain, stiffness and symmetrical synovitis, mainly affecting younger middle aged people

Features:

1. Chronic arthiritis: poly, symmetrical, early morning stiffness, damage and destruction of joints
2. Extra-articular disease can occur - rheumatoid nodules, vasculitis, episcleritis (due to autoantibodies - immune complex)
3. Rheumatoid factor may be detected in blood - IgM autoantibody against IgG (antibody on antibody)

Question 2

Discuss the epidemiology

Answer 2

Affects more women than men, significant disability in adults, genetic component due to specific sequence of amino acids within beta chain of the DR molecule (shared epitope) and environmental component of smoking

Question 3

What are the most commonly affected joint n RA

Answer 3

MCP, PIP, wrist, knees, ankles, MTP

If untreated will result in mechanical change

Joint deformity: 1. swan-neck deformity: hyperextensiton at PIP and hyperflexion of DIP. 2. Boutonnière damage: hyperflexion at PIP (button like)

Question 4

What are the RA pathology

Answer 4

Synovial joint (dactylitis), tenosynovium surrounding tendons (sweeting ulled back if raised finger?), bursa (pocket f fluid)

Subcutaneous nodule: classically on elbow, central area f fibrinoid necrosis surrounded by histiocytes and peripheral layer of connective tissue. Associated with severe disease, extra articlar manifestation and rheumatoid factor

Synovial membrane thickens, chronically inflamed, joint swelling, recruitment of IL-1, il-6, TNF-alpha - pro inflammatory and pleiotropic effect

Question 5

Discuss the antibodies associated with rheumatoid arthritis

Answer 5

1. Rheumatoid factor: antibodies that recognise the Fc region of the IgG as their target antigen, typically IgM antibodies, recognise the Fc IgG.
2. Antibodies to citrullinated peptides antigen (ACPA): antibodies against citrullinated peptides (regulates by Pap) are highly specific for rheumatoid (anti-CCP antibodies)

Question 6

Describe the radiographic abnormalities

Answer 6

1. Extra-juxta osteopenia (thinning of the bone)

2. Later: joint erosions at margins of the joint - joint erosions on the edge

Question 7

Describe the treatment of RA

Answer 7

TNF alpha inhibitor, and sometimes IL-1 and IL-6 nhinitor

Manage Joint pain, MDT approach

Drugs: DMARD, glucocorticoid therapy