SLE Flashcards
(42 cards)
What is SLE?
multisystemic autoimmune disease
What is the pathophysiology of SLE?
- Autoantibodies made against a lot of autoantigens (e.g. ANA) which form immune complexes
- Inadequate clearance of immune complexes results in a host of immune responses which cause tissue inflammation and damage
What are RF for SLE?
- Environmental triggers: EBV
- HLA B8, DR2 or DR3 positive
- Fhx: 10% of patients have 1st or 2nd degree relative with SLE
What is the prevalence of SLE?
0.2%
What is the classic epid of SLE?
- Women 9:1
- Child bearing age
- African Caribbean and Asians
How do you diagnose SLE?
least 4 or more criteria (at least 1 clincial and 1 lab) or biopsy proven lupus nephritis with positive ANA or anti-DNA
What are the categories of symptoms of SLE?
- Acute cutaneous lupus
- Chronic cutaneous lupus
- Non-scarring alopecia
- Oral/nasal ulcers
- Synovitis
- Serositis
- Neurological features
- Fever
- Weight loss
- Raynaud’s phenomenon
What are signs of acute cutaneous lupus?
- malar rash/butterfly
- fixed erythema
- photosensitive rash
What are signs of chronic cutaneous lupus?
- discoid rash
2. erythematous raised patches with adherent keratotic scale and follicular plugging
What does the synovitis affect?
2 or more joints
What are the serositis parts of SLE?
lung, pericardial effusion, pericarditis, pericardial pain
What are possible DDx for SLE?
- Rheumatoid arthritis
- Antiphospholipid syndrome
- Systemic sclerosis
- Mixed connective tissue disease
- Adult Still’s disease
- Lyme Disease
- HIV
Etc
What blood investigations are used for SLE?
- FBC
- APTT
- U+Es
- ESR + CRP
- ANA, dsDNA, Smith antigen
- C3 and C4
What would FBC in SLE show?
- haemolytic anaemia
- leukopenia
- thrombocytopenia
- Leucopenia (WCC<4) at least once or lymphopenia (<1) at least once
- Thrombocytopenia (platelets <100) at least once
What would APTT show for SLE?
prolonged in patients with antiphosphoplid antibodies
What would U+Es in SLE show?
elevated urea and creatinine
What does ESR and CRP like in SLE?
raised ESR and normal CRP
What is ANA, dsDNA, Smith antigen like in SLE?
positive
What other tests should be ordered for SLE?
- Urinalysis
- CXR
- ECG
- renal biopsy
What would urinalysis show in SLE?
- haematuria or (red cell casts)
2. proteinuria (>0.5g/d)
What neurological features are in SLE?
seizures, psychosis, myelitis, neuropathy
What would CXR show in SLE?
- pleural effusion
- infiltrates
- cardiomegaly
Why do you do ECG for SLE?
exclude other causes of chest pain
What labaratory criteria is needed in SLE?
- +Ve ANA (95% positive)
- Anti-dsDNA
- Anti-smith antibodies present
- Antiphospholipid Abs present
- Low complement (C3, C4 or C50)
- +ve Direct Coombs test
