Week 2 - Lec 6 : Immune Disorders

Question 1

Rheumatoid Arthritis:

• What is it?
• Patho
• Symptoms
• Clinical Presentation
• Stages of RA

Answer 1

RA is a systemic autoimmune disease that is manifested with pain & swelling in multiple joints.

Patho:
Inflammation of joint synovial membrane-(Synovial Hyperplasia).
• Activation of B and T lymphocytes; B cells release Rheumatoid Factor (Auto-AB)
• Continued release of inflammatory cells and mediators cytokines are essential in initiation and continuation of rheumatoid inflammation
• TNF-alpha plays a central role in RA: increase tissue adhesion molecules & stimulation of pro-inflammatory cytokines
•results in acute and chronic inflammation.

Symptoms:
• Joint inflammation, malaise, fever, rash, Raynaud Phenomenon( lack of circulation in fingers and toes); lymph node & spleen enlargement, Joint pain, swelling & stiffness >6 weeks duration, fatigue, weakness, loss of appetite, low grade fever; rheumatoid nodules

Clinical presentation:
- Continuous inflammation eventually afflicts the articular cartilage, joint capsule, ligaments and tendons resulting in continuous pain, joint deformity and loss of function

-Symmetric manifestations in smaller joints: wrists, knees, proximal interphalangeal joints, elbows, metacarpophalangeal joints
-Joint deformity seen
late in disease

Steps:

1. Pannus
2. Fibrous ankylosis: bone breakdown w/ fibrous tissue
3. Bony Ankylosis: bone collapses & joint bone fuses

Question 2

Systemic Lupus Erythematosus (SLE)

• What is it?
• Clinical presentation

Answer 2

What is it?

• Deposition of auto-antigens- auto-antibody complexes in organs of patient resulting in multi-system disease with concurrent immunologic reaction.
• Loss of Immunologic Self- Tolerance
• Hyperactivity of B Lymphocytes

Clinical Presentation:

• General: Fever, depression, fatigue, weight loss
• Skin: photosensitivity, butterfly rash, vasculitis, purpura, urticaria
• Chest: Effusion, restrictive lung defect (rare)
• Joints: Arthritis in small joints
• Nervous sytem: Psychosis & etc
• Glomerulonephritis
• Blood: Anemia, lymphopenia, thrombopenia

-Discoid lupus erythematous: Severe inflammation, scarring and rashes on face, scalp and ears

Question 3

Osteoarthritis:

• Clinical presentation
• Patho

Answer 3

Clinical presentation:
- Asymmetric joint involvement; single or many joints
-SYMPTOMS: deep aching pain; stiffness in afflicted joints with <30 mins duration
• Resolves with motion; recurs with rest
• limited joint mobility; instability in weight bearing joints

Patho:
- Primary(Idiopathic) OA: No identifiable cause
- Secondary OA: identified cause (i.e. trauma,
endocrine, metabolic, rheumatologic disorder)
- OA begins with damage to cartilage; chondrocytes attempt to balance injury with repair & healing
( • In on going injury cycle, chondrocytes cannot repair& apoptosis results with further cartilage damage
• Subchondral bone will then release some inflammatory mediators and matrix metalloproteinases [MMP]with further damage the AC.
• Joint space narrows with loss of AC, pain&deformity follow
• Resulting cartilage present becomes soft and less elastic.
• With continued AC breakdown, the subchondral bone becomes
exposed & brittle; micro-fractures develop (i.e.bone rubs on bone)
• Osteophytes develop (new bone forming in joint margin).