Systemic Lupus Erythematosus (SLE)

Question 1

What is SLE?

Answer 1

• Multi-systemic autoimmune disease
• Characterised by presence of anti-nuclear antibodies
• Type 3 hypersensitivity reaction

Question 2

What are the risk factors of SLE?

Answer 2

• Gender (female)
• Age - 15 to 45
• Ethnicity
• Family History
• Smoking
• Drugs
• Sun exposure

Question 3

What are the possible causes of SLE?

Answer 3

• Genetics (associated with HLA B8, DR2, DR3)
• Sex hormone status
• UV light
• Drugs (Procainamide, Hydralzine, Isoniazid, Minocycline, Phenytoin) - Drug induced lupus associated with antihistone antibodies
• EBV

Question 4

What are the clinical features of SLE?

Answer 4

=> General features:

• Fatigue
• Fever
• Mouth ulcers
• Lymphadenoapthy

=> Skin:

• Butterfly rash
• Alopecia
• Photosensitivity
• Livedo reticularis
• Raynaud’s phenomenon

=> MSK:

• Arthralgia
• Non erosive arthritis

=> CVS:

• Pericarditis
• Myocarditis

=> Respiratory:

• Pleurisy
• Fibrosing alveolitis

=> Renal:

• Protenuria
• Glomerulonephritis

=> Neuropsychiatric:

• Anxiety and depression
• Psychosis
• Seizures

Question 5

What is the pathophysiology of SLE?

Answer 5

• Autoimmune condition where the body makes antibodies against its own DNA
• Dead cells and cell fragments are cleared up ineffectively by phagocytes
• Immune complexes travel to lymphoid tissue, where they encounter APC
• Autoantibodies form
• Inappropriate clearance of these immune complexes lead to inflammation and damage

Question 6

What are the investigations in suspected SLE?

Answer 6

=> Bloods - ESR, CRP FBC
FBC reveals pancytopenia 
ESR raised 
CRP NORMAL 
RAISED ESR + NORMAL CRP = SUSPECT SLE

=> Serum autoantibodies 
Anti-dsDNA raised
Anti-Smith raised
C3 and C4 reduced
RF may be raised
Antiphospholipid levels raised 

=> ENA panel test

Question 7

What is the management of SLE?

Answer 7

=> Conservative manegement

• Avoid sunlight
• Use high factor sun block (Hydrochloroquine)
• Topical steroids

=> Mild flares

• Hydrochloroquine or low dose steroids
• Steroid sparing

=> Moderate flares
- DMARDs

=> Severe flares

• Mycophenolate
• Rituximab
• Cyclophosphamide

Question 8

What is antiphopholipid syndrome and its features?

Answer 8

Acquired disorder characterised by predisposition to venous and arterial thrombosis, recurrent fetal loss and thrombocytopenia

=> Features:

• Venous/arterial thrombosis
• Recurrent fetal loss
• Thrombocytopenia
• Prolonged APTT (paradoxical)
• Liverdo reticularis
• Pulmonary hypertension, pre-eclampsia