Systemic lupus erythematosus (MSK) Flashcards
What is systemic lupus erythematosus (SLE)?
Multisystem autoimmune disease that predominantly affects women of childbearing age
What type of hypersensitivity reaction is SLE?
Type 3
Describe the epidemiology of SLE. (3)
- F>M
- onset usually at 20-40 years old
- more common in Afro-Caribbeans
What causes SLE?
Genetic predisposition - HLA-DR2/3
Which genes predispose to SLE? (2)
- HLA-DR2
- HLA-DR3
What systems does SLE frequently involve?
- most frequently involves skin and joints
- serositis, nephritis, haematological cytopenias and neurological manifestations may occur during the course of the disease
- pericarditis, myocarditis, pleuritis, pleural effusion
What is SLE characterised by?
Presence of antinuclear antibodies (ANA)
What syndrome is SLE associated with?
Anti-phospholipid syndrome - increased risk of thrombus formation (recurrent PEs and DVTs) and recurrent miscarriages
What are the clinical features of antiphospholipid syndrome (SLE)? (4)
CLOT
- Clots (thrombosis)
- Livedo reticularis
- Obstetric complications (miscarriages)
- Thrombocytopenia
What do investigations show in antiphospholipid syndrome (SLE)? (2)
- prolonged APTT (paradoxical)
- low platelets (thrombocytopenia)
What antibody is antiphospholipid syndrome (SLE) associated with?
Anti-cardiolipin antibodies
How is antiphospholipid syndrome (SLE) managed?
- low dose aspirin (no previous thromboembolic event)
- lifelong warfarin target INR 2-3 (after initial thromboembolic event) - avoid in pregnant women –> give aspirin and LMWH
What would adult-onset Still’s disease (SLE) present like (variant of juvenile rheumatoid arthritis)? (3)
Triad of:
- joint pain
- spiking fevers
- pink bumpy rash
What are the clinical features of SLE?
- malar (butterfly) rash - erythema over cheeks and bridge of nose, sparing nasolabial folds
- photosensitive rash (after sun exposure - painful and pruritus for few days)
- discoid rash - erythematous raised patches
- fatigue, fever, weight loss
- arthritis and arthralgia (distal symmetrical polyarthritis)
- oral ulcers
- pericarditis or myocarditis
- Raynaud’s phenomenon
What is Raynaud’s phenomenon (SLE)?
Colour changes of the digits induced by cold: white –> blue –> red
How do we treat Raynaud’s phenomenon (SLE)?
Nifedipine
What rashes are seen in SLE? (3)
- malar (butterfly) rash
- photosensitive rash
- discoid rash
What are some extra-articular manifestations of SLE? (8)
- pericarditis
- myocarditis
- pleuritis
- pleural effusion
- serositis
- nephritis
- haematological cytopenia
- neurological manifestations
What are some risk factors for SLE? (5)
- female sex
- age >30
- African descent in Europe and US
- drugs (e.g. procainamide, hydralazine)
- family history of SLE
What are the 1st-line investigations for SLE? (9)
- ANA, anti-dsDNA, anti-Smith
- ESR and CRP
- FBC and differential
- APTT
- U&Es
- urinalysis
- CXR
- ECG
- C3/4 complement
What is often used as a rule-out test for SLE?
Antinuclear antibody (ANA) - very sensitive (positive in most patients), but low specificity (may be positive in other conditions)
i.e. a positive ANA is not diagnostic
When can ANA be negative in SLE?
Rarely, especially in anti-Ro-antibody-positive lupus
What are some highly specific tests for SLE? (2)
- anti-dsDNA
- anti-Smith antibodies
- (ANA sensitive but not specific)
What is elevated in SLE according to disease activity?
ESR
