Thrombotic microangiopathies

出自KMU Wiki

• Risk factors
  • Pregnancy, pills, quinine, RT p’ts given ~OKT3 for rejection, calcineurin inhibitors (cyclosporine, tacrolimus), antiplatelets (ticlopidine and clopidogrel), HIV
• Clinical features
  • Thrombocytopenic purpura, hemolytic anemia, fever, renal failure (esp. HUS), neurologic disturbances (esp. TTP)
• Pathology
  • Endotheliosis with fibrin thrombi
• 1st classification
  • Thrombotic thrombocytopenic purpura (TTP)
  • Hemolytic-uremic syndrome (HUS)
• 2nd classification
  • Adult HUS/TTP
    • Familial: ~ADAMTS13 metalloprotease (that cleaves large multimers of von Willebrand's factor) deficiency
    • Sporadic
      • Some p'ts have antibody to ~ADAMTS13 or thrombospondin receptor on endothelial cells
      • Some p'ts have plasminogen-activator inhibitor 1 ↑
  • Childhood HUS
    • Escherichia coli O157:H7 (occasionally Shigella dysenteriae) causing enterohemorrhagic diarrhea
• Treatment
  • Daily plasmapheresis
  • Patients with childhood HUS from infectious diarrhea are not given antibiotics, as

antibiotics are thought to accelerate the release of the toxin and the diarrhea is usually self-limited