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What are thrombotic microangiopathies?

Current as of 31 July 2026 · added 31 July 2026

Answer: TMAs are a diverse group of diseases that manifest (or are defined by) microangiopathic hemolytic anemia (DAT-negative hemolysis), thrombocytopenia, and end-organ damage.

  • Primary causes: inherited ADAMTS13 deficiency (congenital TTP, cTTP) and acquired ADAMTS13 deficiency (immune TTP, iTTP), plus STEC-HUS.
  • Secondary causes: e.g. HELLP and systemic cancer.
  • Recognition of a TMA is important because prompt treatment may reverse organ injury and improve morbidity and mortality.
  • The most important TMA to learn is immune TTP, because immediate PLEX is standard of care and treatment should not be delayed.

Source: Syndromes of Thrombotic Microangiopathy