AM Report 11/3/16: TTP

Thrombocytopenia is due to three main problems: DECREASED PRODUCTION (bone marrow), INCREASED DESTRUCTION, SPLENIC SEQUESTRATION:

Decreased Production:

  • Aplastic anemia
  • Hematologic malignancies
  • Myelodysplastic syndrome
  • Chronic alcoholism
  • Infiltrative process (myelofibrosis, infection, etc.)

Increased Production:

  • Immune disorders
    • ITP
    • Drug induced (heparin, sulfonamides, thiazides, etc.)
  • DIC
  • TTP
  • HUS
  • Sepsis
  • AIDs/Viral infection
  • Liver Failure

Splenic Sequestration

Causes of MAHA:

  • DIC
  • TTP/HUS
  • Malignant hypertension
  • Mechanical valves
  • HELLP/Pre-eclampsia
  • Scleroderma renal crisis

36792tn

TTP Pentad: ONLY PRESENT IN 1/3 OF PATIENTS

  • Thrombocytopenia
  • MAHA (schistocytes on smear)
  • Acute renal insufficiency
  • Fevers
  • Encephalopathy

*Only need thrombocytopenia and MAHA to diagnose

Triad more common:

  • Elevated LDH (tissue hypoxia/injury)
  • Schistocytes
  • Thrombocytopenia

ADMTS 13 Testing

  • Protease that cleaves vWF multimers; deficiency leads to increase vWF leading to platelet aggregation (thrombocytopenia) and disruption/breaking of RBCs (MAHA)

Level of activity:

  • >50% ~ unlikely TTP
  • <10% ~ suggests TTP

*presence of ADAMTS 13 inhibitor suggests acquired TTP; negative suggests hereditary.

Treatment:

  • Plasma exchange
  • If unavailable – infuse FFP
  • Other options: steroids, splenectomy, rituximab, vincristine

* AVOID PLATELET TRANSFUSION AT ALL COSTS!

HUS:

  • Usually occurs in children ~ associated with E. coli 0157:H7
  • Most patients don’t have wide-spread symptoms; besides heme changes, renal involvement is the rule
  • In adults => progressive renal failure => ESRD
  • Supportive treatment in children, assume TTP in adults

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