SLE

Question 1

Why type of hypersensitivity reaction is SLE an example of?

Answer 1

Type III - immune complex mediated

Question 2

What is SLE?

Answer 2

It is an autoimmune condition in which immune complexes cause damage to the blood vessels and connective tissue

• There are periods of remission from symptoms and ‘flare-ups’
• Cause of SLE is unknown
• Disease can affect ALL systems in the body

Question 3

How does SLE typically present?

Answer 3

1. Low grade fever
2. Non-specific fatigue
3. Arthralgia (small joints of hands. wrists, knees)
4. Weight changes
5. Dermatological issues (malar facial rash in butterfly pattern)
6. Photosensitivity
7. Discoid lesions
8. Alopecia
9. Mouth ulcers

Also affects:
- Pulmonary, GI, cardiac + haematologic and neuropsychiatric systems

Renal nephritic disease is one of the most dangerous complications

Question 4

What is the antigen in SLE?

Answer 4

Antigen appears to be DNA, as people with SLE express high levels of anti-nuclear antibodies (against deoxyribonucleic acid and ribonucleoproteins
There is also elevated expression of high mobility group box 1 (HMGB1) - nuclear protein participating in chromatin architecture and transcriptional regulation

Question 5

What is Jaccoud arthropathy?

Answer 5

Chronic non-erosive reversible joint disorder, commonly resulting in hand deformities

• ulnar deviation
• MCP subluxation

Question 6

What subtypes of antinuclear antibodies are linked to SLE?

Answer 6

Anti-smith and anti-double stranded DNA (dsDNA)
- anti-dsDNA antibodies are present in 70% of cases of SLE
Anti-histone antibodies (drug-induced SLE)
Anti-U1 RNP (also in systemic sclerosis and mixed connective tissue disease)
Anti-(SS-A)/-Ro and Anti-(SS-B)/-La (also in Sjögren’s syndrome

Question 7

What are the treatment options for SLE?

Answer 7

1. simple prevention of exposure to triggers
2. NSAIDs - mild to moderate
3. DMARDs - moderate to severe
   - cyclophosphamide (cross links DNA = cell death)
   - mycophenolate mofetil
   - MTX
   - Hydroxycholorquine
   - Tacrolimus
4. Corticosteroids for flares
5. IV immunoglobulins
6. Biologicals
   - Belimumab: inhibits B cell activating factor
   - Rituximab: CD20 blocker