Week 7 pathology

Question 1

Osteoarthritis

What is it? Who does it affect? What is the pathophysiology? What is the clinical presentation?

Answer 1

• Non-infammatory process that affects large weight bearing joints and phalangeal joints
• Unilateral disease
• Obesity and trauma are risk factors

pathophysiology:
- The erosion of the articular hyaline cartilage allows for the bones to rub together causing eburnation (bony sclerosis). In addition, bone grows outward and forms osteophytes (bone spurs). Finally, the exposed bone can fracture causing synovial fluid to leak into the bone forming subcondral cysts.
Bone spurs are more obvious in the finger joints and form Heberden (DIP) and Bouchard’s (PIP) nodes

Clinical presentation:

• Morning stiffness that goes away <1 hour
• Pain is worse at night
• usually no swelling

Question 2

Rheumatoid arthritis

What is it? Who does it affect? What is the pathophysiology? What is the clinical presentation?

Answer 2

• Chronic inflammatory autoimmune disease that affects multiple tissues, but mostly joints
• Bilateral presentation

pathophysiology:
-Unknown antigen is presented to T cells, which causes T cell activation. T cells activate B cells that secrete antibodies and activate more macrophages that release more cytokines. This causes inflammation and proliferation of the synovial membrane and accumulation of granulation tissue withing the synovial tissue forming papillary like projections called pannus. In addition, bone and carilage errosion occurs.

Clinical presentation:

• Morning stiffness that lasts >1 hour
• Swan neck and/or boutonniere deformity
• Rheumatoid nodules (typically seen near the olecranon

Question 3

Systemic lupus erythematous (SLE)

What is it? Who does it affect? What is the pathophysiology? What is the clinical presentation? What is/are the cause(s) of death from lupus? What is/are the cause(s) of death with lupus?

Answer 3

• Immune-complex mediated (type III hypersensitivity)
• primarily affects African women
• Low C3 and C4

pathophysiology:
- Immune complexes lodge into normal tissues. Granular tissue recognize the complexes and degranulate causing damage to the surrounding tissue.

Clinical presentation:

• Nephritis
  
  • immune complexes in glomeruli
• Malar and discoid rash
  
  • epidermis/dermis separation
• Endocarditis (Libman-Sacks)
  
  • immune complexes lodge into cardiac tissue (can dislodge)
• Pleuritis and pericarditis
• Arthiritis
• Neuro disorders

Main cause of death from lupus:

• Renal
• CNS

Main cause of death WITH lupus:

• infections (steroid use)
• Premature cardiac disease

Question 4

Giant cell arteritis

What is it? Who does it affect? What does it affect? What is the clinical presentation? What should you treat the patient with and why do you want to do it asap?

Answer 4

• Large artery vasculitis
• Affects elderly
• Immune complexes lodge into temporal artery. Leads to constriction of the artery and can cause blindness

Clinical presentation:

• Temporal pain (headache)
• visual impairment

Treat the patient with steroids to prevent blindness!!

Question 5

Takayasu’s arteritis

What is it? Who does it affect? What does it affect? What is the clinical presentation?

Answer 5

• aka pulseless disease
• Large artery vasculitis
• Affects young asian women
• Immune complexes lodge into aortic arch. Leads to constriction of the artery. It obliterates the pulse

Clinical presentation:

• fever
• Night sweats

Question 6

Kawasaki disease

What is it? Who does it affect? What does it affect? What can it affect? What is the clinical presentation? How do you treat it?

Answer 6

• Medium artery vasculitis
• Affects infants and kids
• Can cause coronary artery vasculitis and coronary aneurysms

clinical presentation:

• febrile
• strawberry tongue
• Cervical lymphadenopathy

Treatment:

• Intravenous immunoglobulin
• aspirin (the risk of kawasaki outweighs the risk of developing Reye’s syndrome)

Question 7

Polyarteritis nodosa

What is it? Who does it affect? What does it affect?

Answer 7

• Medium artery vasculitis
• Typically affects individuals with Hep B
• Affects kidneys, coronary arteries, joints, and GI

Question 8

Wegener’s granulomatosis

What is it? What does it affect? In what organs?

Answer 8

• Small artery vasculitis
• Associated with C-ANCA
• necrotizing granulomas destroy blood vessels and surrounding tissue in the lungs and/or kidneys

Question 9

What is Churg-Strauss Syndrome?

What is it? What does it affect? In what organ?

Answer 9

• Small artery vasculitis
• Associated with P-ANCA
• Allergy mediated (eosinophils) vasculitis of pulmonary vasculature

Question 10

Microscopic polyangiitis

Answer 10

• Small artery vasculitis

- Associated with P-ANCA

Question 11

Henoch-Schonlein purpura

Answer 11

Immune-complex mediated (IgA and C3)
Likely triggered by infection
Affects kidneys —> hematuria
Clinical triad: purpura, arthritis, abdominal pain

Question 12

Pseudogout

Answer 12

• Calcium pyrophosphate crystals

- Positively birefringent rhomboid (coffin shaped) crystals

Question 13

Gout

Answer 13

• Non autoimmune disease
• Higher than normal levels of uric acid (make too much or excrete too little)
• Deposit in joint tissue (tophus)
• Can affect kidney (stones)
• deposition causes inflammatory response
• Negatively birefringent needle shaped crystals
• can erode bone (bites)

Question 14

How do you test for RA? Does this confirm the diagnosis?

Answer 14

Rheumatoid factor

No. Diagnosis requires evidence of tissue damage

Question 15

How do you test for SLE? Does this confirm the diagnosis?

Answer 15

Anti-nuclear antibodies (ANA)

No. Diagnosis requires evidence of tissue damage

Question 16

dermatomyositis

Answer 16

Rash 
- face (includes eyelids)
- extensor surfaces: hands, knees, elbows
Nailfold capillary changes
Muscle weakness