Thrombotic microangiopathies (TMAs)

Thrombotic microangiopathies (TMAs)

• are a group of disorders characterized by thrombocytopaenia, microangiopathic heamolytic anaemia, and ischaemic end-organ damage due to microvascular thrombosis
• this systemic disorder can affect any organ system, including the brain, heart, and gastrointestinal tract (1)
  • however, the kidney is the most frequently affected organ

Thrombotic microangiopathy is classified as

• primary
  • including thrombotic thrombocytopenic purpura [TTP] and haemolytic uraemic syndrome [HUS]) or
• secondary
  • including disseminated intravascular coagulation [DIC],
  • vitamin B12 deficiency,
  • autoimmune diseases,
  • uncontrolled hypertension,
  • infections, medications,
  • malignancies
    • in cancer patients, TMA can arise from
      • (1) the cancer itself (cancer-associated TMA),
      • (2) cancer treatments, or
      • (3) unrelated causes
    • may be the first sign of undiagnosed cancer, but it is more frequently seen during the progression of known metastatic cancer (2)

Reference:

1. Jalal A, Atari M, Hassanein M, et al. Thrombotic Microangiopathy and the Kidney. [Updated 2025 Mar 4]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-.
2. Sullivan CM et al. Breast Cancer–Associated Thrombotic Microangiopathy: The Paradox of Stable Scans and Unstable Blood. AIM Clinical Cases.2025;4:e250421.