Systemic lupus erythematosus is a chronic autoimmune connective tissue disease affecting multiple systems.
Incidence of SLE is increased in females and especially those of Afro-Caribbean origin.
Diagnosis is by fulfilling 4 of the 11 criteria of the American College of Rheumatology:
- Malar rash
- Discoid rash
- Photosensitivity
- Oral ulcers
- Arthritis
- Serositis – either pleuritis or pericarditis
- Renal disorder –persistent proteinuria or cellular casts
- Neurological disorder – seizures or psychosis
- Haematological disorder – haemolytic anaemia or leukopeania or lymphopenia or thrombocytopenia
- Immunologic disorder –
- anti-dsDNA antibody or anti-Sm antibody or positive antiphospholipid antibodies
- with either abnormal serum anti-cardiolipin antibody levels or positive lupus anticoagulant or false positive serological testing for syphilis
- Abnormal ANA titre
Anti-dsDNA is positive in 70% of SLE patients (and 0.5% general population)
ANA is positive in 90% of SLE patients (and 30% general population)
Complications/associations of SLE
- more prone to infections
- increased risk of non-Hodgkins lymphoma
- associated with antiphospholipid syndrome, which confers increased risk of thrombosis and miscarriage
- lupus glomerulonephritis – occurs in 39%
Blood tests in flares of SLE may show:
- Raised Anti-dsDNA titres
- Decreased C3/C4 levels
- Raised ESR
Management:
- sunscreen
- NSAIDs
- Corticosteroids
- Hydroxychloroquine
- DMARDs (azathioprine, methotrexate)
Small print gem: Libman-Sacks endocarditis is an endocarditis found in SLE patients with non-infective vegetations, most commonly affecting the mitral valve.
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