MSK and Rheum - SLE, Antiphospholipid Syndrome, Sjögrens Syndrome, Drug-Induced Lupus Flashcards
Systemic Lupus Erythematosus (SLE) - what is it?
Inflammatory multi-system autoimmune condition affecting connective tissue
Manifests differently in different patients
SLE - What does the erythematosus in Systemic lupus erythematosus refer to?
Refers to the typical red malar rash that occurs across the face
SLE - how does it present in terms of time period?
RELAPSING-REMITTING COURSE, with flares and periods where symptoms are improved
SLE - pathophysiology
- SLE is characterised by anti-nuclear antibodies
- These are antibodies to proteins within the persons own cell nucleus
- This causes the immune system to target theses proteins
- When the immune system is activated by these antibodies targeting proteins in the cell nucleus it generates an inflammatory response
TYPE 3 HYPERSENSITIVITY REACTION
SLE - what are flare ups/flares triggered by?
Oestrogen-containing contraception
Overexposure to sunlight
Infections
Stress
SLE - what is the classical presentation?
Some combination of:
1. Systemic upset (fever / myalgia / fatigue / weight loss)
- Joint and/or skin involvement
SLE - what are the dermatological presentations?
Photosensitivity - most common dermatological feature of SLE, occurs in form of a malar rash
Mouth / nose / genital ulcers
Cutaneous vasculitis - which manifests as splinter haemorrhages / purpura
Discoid rash
SLE - what are the CV presentations?
Pericarditis, which is the MOST COMMON cardiac feature of SLE
Myocarditis, which can present as arrhythmias and heart failure
Raynaud’s phenomenon
SLE - what are the respiratory issues that can occur?
Pleurisy
Pleural effusions
Pneumonitis - in the acute form can mimic pneumonia, chronic pneumonitis causes pulmonary fibrosis
SLE - what renal manifestations can occur?
LUPUS NEPHRITIS - most common cause of lupus-related death
Can be asymptomatic, before it presents as either nephritic or nephrotic syndrome
Patients should be monitored regularly for renal disease
Monitoring includes checking BP (sudden hypertension) and urinalysis (for proteinuria or haematuria)
SLE - what are the neurological manifestations?
Seizures
Migraines
Peripheral neuropathies
Psychiatric symptoms including psychosis or depression or anxiety
SLE - what are the haematological presentations?
Anaemia of chronic disease (common)
Lymphopenia (common)
Autoimmune haemolytic anaemia
Thrombocytopenia
Leucopoenia
SLE - what are the GI manifestations that can occur?
Peritonitis (aseptic)
Hepatosplenomegaly
SLE - what are conditions that can develop
Secondary Sjogren’s syndrome
Secondary anti-phospholipid syndrome
Mixed connective tissue disease
SLE - what antibodies are associated with SLE?
Antinuclear antibodies (ANA) - 99% are positive, high sensitivity makes it a useful rule out test, but has low specificity
20% are rheumatoid factor (Rf) positive
anti-dsDNA: highly specific (> 99%), but less sensitive (70%)
anti-Smith: highly specific (> 99%), sensitivity (30%)
SLE - how do you diagnose?
Use SLICC Criteria
Involves confirming the presence of antinuclear antibodies (ANA) and establishing ≥4 findings with at least one clinical feature and one laboratory test (like ANA or anti-dsDNA)
SLE - what are the preventative steps a patient can take?
Avoid triggers for flares so:
Avoid oestrogen-containing contraception
Avoid overexposure to sunlight
Infections
Stress
SLE - what is the pharmacological management?
No cure, immunosuppression is the mainstay of treatment, aim to reduce symptoms
1st line - HYDROXYCHLOROQUINE and NSAIDs, for MILD LUPUS
2nd line - Commonly used immunosuppressants in resistant or more severe lupus: Methotrexate, Mycophenolate mofetil, Azathioprine,Tacrolimus, Leflunomide, Ciclosporin
Biological therapies - severe disease or not responded to other treatments, Rituximab, Belimumab
Antiphospholipid syndrome - what is it?
Autoimmune disorder characterised by blood becoming more prone to clotting and raised antiphospholipid antibodies
Patient is in a hyper-coagulable state
Antiphospholipid syndrome - what are the main features? CLOT
C - Clots: usually venous (DVT and PE), can also be arterial (stroke and MI)
L - Livedo Reticularis: mottled, lace-like appearance of the skin on the lower limbs
O - Obstetric loss: recurrent miscarriages, pre-eclampsia, stillbirth
T - Thrombocytopenia
Antiphospholipid syndrome - what are the associated antibodies and what investigation do you have to do?
One or more of the following positive blood tests are needed on 2 occasions, 12 WEEKS APART to diagnose APS:
- Anti-cardiolipin antibodies (aCL)
- Anti-beta-2 glycoprotein I antibodies
- Positive lupus anticoagulant assay (LA)
Antiphospholipid syndrome - management
Reduce RF’s for thromboembolism
Venous - Avoid oestrogen-containing contraception/HRT and long periods of immobility
Arterial - Control CVS risk factors, BP, BM, smoking
Treatment of VTE:
- Not recommended prophylactically in patients that have not experienced a thromboembolic event
- If VTE event, lifelong warfarin / NOAC
- Warfarin is teratogenic, so use LMWH in pregnancy
Antiphospholipid syndrome - passmed’s ‘key point for the exam’ about APTT, and what is APTT?
APTT measures how long it takes your blood to form a clot
‘A key point for the exam is to appreciate that antiphospholipid syndrome causes a paradoxical rise in the APTT. This is due to an ex-vivo reaction of the lupus anticoagulant autoantibodies with phospholipids involved in the coagulation cascade’
Sjögrens syndrome - what is it?
Autoimmune disorder affecting exocrine glands, causing dry mucosal membranes
