Systemic Lupus Erythematosus (SLE)

Question 1

SLE (lupus) definition

Answer 1

systemic autoimmune disease that can affect virtually any organ system
-characterized by multiple relapses and remissions over decades

Question 2

SLE Epidemiology (6 factors)

Answer 2

• affects around 500,000 people in the US
• 85-90% of sufferers are women (10:0)
• Occurs in 1:250 african-american women, 1:1000 caucasian women
• Most common, complex and serious of the autoimmune disorders
• Typical onset between 15 and 44 years
• No 2 cases of SLE are alike

Question 3

SLE Etiology (3 factors)

Answer 3

1. Genetics: Runs in families and twins, with at least 20 loci identified
2. Hormones: low androgen, high estrogen
   - Onset between menarche and menopause
3. Triggers: UV light, Prescription meds, abnormal immune responses, recurrent EBV (Epstein Barr Virus) infection

Question 4

SLE Pathophysiology (3 factors)

Answer 4

Phenomenon called “loss of immune self-tolerance”:

1. Impaired clearance of apoptotic cells
2. Excessive CD4 T cell or reduced regulatory (suppressor) T cell response
3. B cells are stimulated to produce antibodies against native tissues (autoantibodies)

Question 5

SLE Antibodies (to blood cell surface antigens)

Answer 5

• Type 2 hypersensitivity

- Reduced blood cell counts from anemia, leukopenia, and thrombocytopenia

Question 6

SLE Antibodies (to DNA, other nuclear and cytoplasmic proteins)

Answer 6

• Type 3 hypersensitivity
  1. Formation of immune complexes that become trapped in tissues (vascular system, kidneys)
  2. Intense inflammatory response (-itis)
  3. Autoamplification (inflammation of the area leads to more inflammatory response and a positive feedback loop)

Question 7

SLE Clinical Presentation (6 factors)

Answer 7

1. Slow and symptoms are on-off (exacerbations and remissions)
2. Polyarthralgia (90%)
   - Pain in multiple joints and symmetric
3. Vasculitis/rash (70-80%)
4. Renal Disease (40-50%)
5. Hematologic abnormalities (50%)
6. Cardiovascular disease (30-50%)

Question 8

11 clinical findings of SLE

Answer 8

1. Antinuclear antibodies
2. Arthritis of 2+ peripheral joints
3. Butterfly (malar) rash
4. Discoid rash
5. Hematologic disorders
6. Immunologic disorders
7. Neurologic disorders (storke)
8. Oral/nasopharyngeal ulcers
9. Photosensitivity rash
10. Renal Disorder
11. Serositis (membrane inflammation)

Question 9

SLE Pathology vs symptom (type II’s)

Answer 9

1. Platelet surface > platelet cells > thrombocytopenia
2. RBC surface > red blood cells > anemia
3. WBC surface > white blood cells > leukopenia

Question 10

SLE Pathology vs symptom (type III’s)

Answer 10

1. DNA, other nuclear or cytoplasmic antigens>kidney glomerular apparatus>glomerulonephritis
   2 “ “ >joints>arthritis
2. ” “>skin>dermatitis
3. ” “>lungs, the membrane surrounding the lungs>pleuritis
4. ” “>the membrane surrounding the heart>pericarditis
5. ” “>brain, CNS>Seizures
6. ” “>capillaries, blood vessels, vasculitis

Question 11

SLE Patient Assessment (5 factors)

Answer 11

1. Joint X-ray
2. Antinuclear antibody (ANA) test
   - serological way of testing antibodies floating in blood
3. Anti-native DNA antibody test (50-60%)
4. Anti-smith antibody test (20%)
   - absolutely specific to SLE, if patient is positive for this Ab, they have SLE
5. Elevated ESR
   - Erythrocyte sedimentation rate (M=10, F=15), if above these values, its a cue to SLE

Question 12

SLE Prognosis

Answer 12

1. Complications:
   - Early: Infection (may be taking immunosuppressants that inhibit immune defenses); renal failure; cerebral hemorrhage
   - Late: heart attack; stroke; cancer; bone disease
2. Patient monitoring
   - Response to symptomatic therapy
   - 10 year survival exceeds 90%