Systemic Lupus Erythematosus

Basics

Description

  • Chronic autoimmune disease; peak onset between ages 15 and 40 yr; characterized by flares and remissions
  • Multisystem disease with diverse clinical manifestations:
    • Mucocutaneous:
      • Most commonly involved system
      • 4 specific skin rashes
    • Arthritis
    • Cardiac:
      • Endocarditis
      • Myocarditis
      • CHF
      • Conduction abnormalities
      • Atherosclerosis
      • MI
    • Renal:
      • Glomerulonephritis
      • Renal failure
    • Pulmonary:
      • Pleural effusion (usually exudative)
      • Pneumonitis/pleuritis
      • Pulmonary hemorrhage
      • Pulmonary embolism
      • Pneumonia
      • Pulmonary edema
      • Pulmonary hypertension
    • Neurologic:
      • Lupus cerebritis
    • Vascular:
      • Vasculitis
      • Thrombosis
      • Atherosclerosis
    • GI:
      • Peritonitis
      • Mesenteric vasculitis and ischemia
      • Pancreatitis

Pediatric Considerations
  • Neonatal lupus may occur when maternal autoantibodies cross the placenta:
    • Associated with transient anemia and thrombocytopenia
  • Congenital heart block is the most serious complication


Geriatric Considerations
  • 10 times greater risk of MI due to atherosclerosis
  • High incidence of osteoporosis related to chronic steroid use

Risk Factors

Genetics
  • More common in females than males (9:1 ratio)
  • More common in women of childbearing age
  • More common in African Americans
  • Higher frequency of systemic lupus erythematosus (SLE) and other autoimmune diseases among first-degree relatives

Etiology

  • Autoantibody production against cell nucleus and cytoplasmic structures, leading to inflammatory changes, vasculitis, and immune complex deposition in multiple organ systems
  • A significant percentage of patients have an associated antiphospholipid syndrome:
    • Characterized by antibodies against cellular phospholipid components
    • Tendency toward recurrent vascular thrombosis
  • Lupus is a chronic disease with several exacerbating factors:
    • Infection
    • Sun exposure
    • Fatigue
    • Trauma
    • Medications (sulfonamides)
    • Stress
    • Diet
  • Drug-induced lupus is a milder disease that eventually resolves once the drug is discontinued. Usually presents with skin and joint manifestations while renal and neurologic involvement is rare
  • Common medications that induce lupus include:
    • Chlorpromazine, methyldopa, procainamide, hydralazine, isoniazid, quinidine, minocycline

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