Sle | Anatomy2Medicine
Sle Pathophysiology

Sle

 

  • Systemic lupus erythematosus (SLE)
    • most often affects women (80% of patients), usually those of childbearing age.
  • Clinical manifestations
  • Fever, malaise, lymphadenopathy, and weight loss
      • Joint symptoms, including arthralgia and arthritis
  • Skin rashes
        • a characteristic butterfly rash over the base of the nose and malar eminences (MCQ)
        • often with associated photosensitivity (MCQ)
  • Raynaud phenomenon (MCQ)
        • manifested by vasospasm of small vessels, most often of the fingers
  • Serosal inflammation, especially pericarditis and pleuritis
      • Diffuse interstitial pulmonary fibrosis, manifest as (MCQ)
  • interstitial pneumonitis
  • diffuse fibrosing alveolitis
      • Libman-Sacks Endocarditis (MCQ)
        • Due to characteristic atypical nonbacterial verrucous ¬†form
        • vegetations are seen on both sides of the mitral valve leaflet. (MCQ)
  • Immune complex vasculitis
        • Seen in vessels of almost any organ.
        • In the spleen, perivascular fibrosis with concentric rings of collagen around splenic arterioles results in a characteristic onion-skin appearance. (MCQ)
      • Glomerular changes
        • severe diffuse proliferative disease with marked
        • subendothelial and mesangial immune complex deposition is seen
        • endothelial proliferation is seen
  • indistinguishable from idiopathic membranous glomerulonephritis due to thickening of basement membranes
        • wire-loop appearance seen by light microscopy. (MCQ)
          • Occur due to subendothelial immune complex deposition (MCQ)
  • Neurologic and psychiatric manifestations
  • Eye changes
        • yellowish, cotton wool-like fundal lesions (cytoid bodies) (MCQ)
  • Laboratory findings
    • LE test is based on the LE phenomenon
        • It occurs in vitro
  • mediated by an ANA known as antinucleosome-specific autoantibody.
        • Procedure
          • morphologically characteristic LE cells are formed in a mixture of mechanically damaged neutrophils and autoantibody-containing patient serum.
        • it is positive in only about 70% of cases
    • A positive test result for ANA
        • seen in almost all patients with SLE.
        • ANAs are also found in patients with other connective tissue diseases.
  • The ANA test becomes almost specific for SLE when the antinuclear antibodies react with double-stranded DNA. (MCQ)
        • When this reaction is assessed by microscopic examination of cells using immunofluorescent techniques, a characteristic peripheral nuclear staining, or “rim” pattern, is seen. (MCQ)
        • ANAs that react with Sm (Smith) antigen, a ribonucleoprotein, are also highly specific for SLE. (MCQ)
  • Serum complement is often greatly decreased, especially in association with active renal involvement. (MCQ)
  • Immune complexes at dermal-epidermal junction are demonstrable in skin biopsies.
  • Biologic false-positive tests for syphilis (MCQ)
      • Occur due to anticardiolipins, a form of antiphospholipid antibody
      • occur in approximately 15% of patients

may be the earliest laboratory abnormality in some cases of SLE.