What are connective tissue diseases?
Diseases characterized by the presence of spontaneous over activity of the immune system.
Not diseases of connective tissue
Which part of the body does SLE affect?
Any part of the body
Systemic lupus erythematous is an example of which type of hypersensitivity reaction?
(Immune complex mediated)
Which types of people are more susceptible to SLE?
- Hispanic americans
What hormone is thought to be associated with increased chances of developing SLE?
Which environmental factors may trigger SLE?
- Silica dust or cement
- UV light
Which virus is known to induce SLE?
What is the pathophysiology behind SLE?
- There is an increase in self cell death
- Defective apoptosis occurs
- Necrotic release of nuclear material occurs
- There is delayed clearance of nuclear material and autoantibodies are made against this material
- Immune complex formation occurs
Why is renal disease a major worry in SLE?
It is symptomless
Eventuallu will lead to necrosis and scarring
Why does SLE lead to necrosis and scarring in the kidneys?
- Immune complexes are deposited in the mesangium
- Complement is activated, leukocytes and other inflammatory cells are attracted
- Necrosis and scarring results
Where may ulcers be found in a patient with SLE?
Mouth (or nasal) ulcers
How is SLE diagnosed?
(>= 4 criteria with at least 1 clinical and 1 labratory investigation required for diagnosis OR biopsy proven lupus nephritis and the presence of ANA or Anti dsDNA)
SLE can be associated with thrombocytopenia, what is this?
A low platelet count
How does discoid lupus erythematous differ in terms of facial rash, with SLE?
There is a scaly surface to the rash, which is also generally more well demarkated
How can the hair be affected in SLE?
Alopecia can occur
Describe the facial rash of SLE and the area(s) it avoids
- Butterfly malar rash
- Space naso-labial folds
- Can be associated with UV light exposure
Jaccoud's arthritis is associated with SLE, what is it?
Inflammation of the joint capsule
- MCP joint subluxation (of 2nd to 5th digits) and hyperextension at the related PIP joints
- This is deforming, yet reversible
In SLE it is not uncommon for patients to present with percarditis or pleural effusion. Why is this?
SLE can cause serositis
If SLE impacts the kidneys, causing lupus nephritis, what characteristic features will be shown on urinalysis?
- Proteinuria of >500mg in 24 hours
- Red cell casts (blood in urine)
If either of these features is present then renal biopsy is required
What are some common neurological features of SLE?
- Headache/migraines (most common)
- Foot drop
- Mononeuritis multiplex
- Cranial or peripheral neuropathy
What are some haematological symptoms in SLE?
- Haemolytic anaemia
What does anti-phospholipid syndrome involve?
Thrombosis of arteries and/or veins
What is the term given to the mottled, net like skin appearance seen in patients with anti-phospholipid syndrome?
Which antibody is present in almost all SLE patients, but has a relatively low level of specificity?
When would a raised ANA (>= 1 : 160) be suggestive of SLE?
Symptoms are present
Other anti-nuclear antibodies are high
Which antibody occurs in around 60% of patients with SLE, but is highly specific?
(anti-double stranded DNA antibody)
It can be associated with Lupus Nephritis
Which antibody associated with SLE is also associated with the skin manifestations of the disease?
Pregant women can pass on this antibody to their unborn child which can result in symptoms such as heart block or neonatal LE
Anti-Ro is associated with which other antibody?
Which antibody is very specific for SLE and has probable association with neurological involvement?
What are the three anti-phospholipid antibodies?
- Anti-cardiolipin antibody
- Lupus anticoagulant
- Anti-beta 2 glycoprotein
What is the criteria involving anti-phospholipid syndrome antibodies in order for a diagnosis to be made?
They must be positive on 2 occasions 12 weeks apart
How is CRP affected in SLE?
It remains unchanged
(ESR/PV will increase with active disease however)
How are C4 levels impacted in SLE?
They are reduced - C4 is used up to form immune complexes
Everyone with SLE is given which anti-malarial drug?
Which treatments (pharmacological) can be given for SLE?
- Steroid (not used long term)
Which immunosupressives can be given for SLE, which is normally used and when may the other three not be used?
- Cyclophosphamide (usually used)
- Mycophenolate mofetil
Careful use of immunosuppressives is essential since they can be teratogenic in pregnancy
What impact do immunosuppressive drugs have on the bone?
They cause bone marrow suppression
Which biological agents may be used in SLE?