Systemic lupus erythematosus (MSK) Flashcards
(40 cards)
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 (/pleuritis/pleural effusion)
- 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
