SLE Flashcards
What is the general pathophysiology behind SLE
Autoabs made against a variety of auto antigens which form immune complexes
Poor clearance of immune complexes results in a host of immune responses -> tissue inflammation and damage
What sex is more commonly affected?
Female 9:1
What group of people is it more common in?
Afro-caribbean and Asians
What is the usual age of onset ?
20-40
What genes is it associated w?
HLA B8, DR2, DR3
How is a diagnosis made?
≥ 4 criteria (1 clinical and 1 lab)
OR
biopsy proven lupus nephritis w + ANA or antiDNA
What are the 11 clinical criteria?
- Acute cutaneous lupus
- Chronic cutaneous lupus
- Non-scarring alopecia
- Oral/nasal ulcers
- Synovitis
- Serositis
- Urinalysis - proteinuria or red cell casts
- Neuro features
- Haemolytic anaemia
- Leucopenia
- Thrombocytopenia
What are the lab criteria?
- +ve ANA
- Anti-dsDNA
- Anti-smiths abs
- Anti-phospholipid abs
- Low complement (3,4,50)
- direct Coombs test
What are the features of acute cutaneous lupus ?
- malar rash
- fixed erythema, flat or raised over malar eminence, sparing nasolabial folds
- Bullous lupus - toxic epidermal necrolysis variant of SLE
- Photosensitive rash
- maculopapular lupus rash
What are chronic cutaneous features of lupus?
- discoid rash - erythematous scaly well demarcated rash in sun exposed areas
lesions may progress to become pigmented + hyperkeratotic before atrophic
3 stage rash - inc ears, cheeks, scalp, forehead and chest: erythema ->pigmented hyperkeratotic oedematous papules -> atrophic depressed lesions
How many joints need to be affected by synovitis to meet the clinical criteria?
≥2 joints or ≥2 tender joints w >30mins morning stiffness
What are the features of serositis as part of the clinical criteria?
a. lungs - pleurisy, pleural rub, effusion
b. Pericardial - pain >1day, effusion, rub or pericarditis on ECG
What are the possible neurological features of lupus?
seizures psychosis mononeuritis multiplex myelitis peripheral/cranial neuropathy Cerebritis/acute confusional state
What levels must be met to fit the criteria for leucopenia?
WCC<4 at least once
OR
Lymphopenia <1 at least once
What levels must be met to fit the criteria for thrombocytopenia?
platelets <100
What are non-specific features of SLE?
Malaise myalgia fever fatigue lymphadenopathy weight loss nailfold infarcts non-infective endocarditis Raynauds
How would you monitor activity of SLE?
- Anti-dsDNA ab titres
- Complement: low C3/C4
- ESR
What marker is usually normal in SLE that if raised would point ti another diagnosis and what would they be?
CRP
If raised consider infection, serositis or arthritis
What are the general measures in managing SLE?
- High factor sun cream
- Hydroxychloroquine
- Screen for comorbidities + med toxicity
How would u manage skin flares?
trial topical steroids
What would u give for maintenance therapy?
- NSAIDs (unless renal disease)
- Hydroxychloroquine
- Steroid sparing agents: azathioprine, methotrexate, mycophenolate
- Belimumab - add on for auto ab disease w high activity
What is the rx of mild flare?S
hydroxychloroquine
or
high dose steroids
What is the rx of mod flares?
DMARDs
or
mycophenolate
When does SLE become severe and what is the rx of severe flares?
If organ or life threatening e.g. haemolytic anaemia, nephritis, severe pericarditis or CNS disease urgent high dose steroids mycophenolate rituximab cyclophosphamide
What drugs cause drug induced lupus
isoniazid hydralazine procainamide quinidine chlorpromazine mincocycline phenytoin anti-TNFs
What are the main signs in drug induced lupus?
skin and lung
