Thrombotic Thrombocytopenic Purpura (TTP)



Background

Small vessel thrombosis ⇒ thrombocytopenia (like HUS... but):

  • Haemolytic anemia (±dark urine)
  • Thrombocytopenic purpura
  • Neurologic abnormalities (more than in HUS)
  • Fever (seen in 50%)
  • Renal disease (less than in HUS)

Clinical

  • Recent triggering infection (e.g. diarrhoea) or cancer or antiplatelet drugs.
  • Neurological dysfunction ± petechiae.

Differential Dx

Investigations

  • Septic screen (& simultaneous resusc.)
  • FBC (and smear in lab), INR
  • U&E, LFT (LDH)
Parameter ITP TTP DIC
Aetiology Antiplatelet antibodies Endothelial defect Thrombin excess
Clinical Not sick Sick Sick
Red cells NL Schistocytes Schistocytes ±
PT (INR) NL NL/↑ ↑↑
APTT NL NL/↑ ↑↑
Fibrinogen NL NL ↓↓
FDP / D-dimers NL ↑↑
Therapy Steroids, IVIG, Splenectomy; Plasma exchange Treat cause, Plasma/platelets

Management

  • If any doubt, treat as septic (early fluid resusciattion, antibiotics, ±inotropes)
  • Involve ITU and haematology early
  • Octaplas in preference to FFP
  • Plasma exchange (haematologist)


Content By Dr Íomhar O' Sullivan 25/01/2019. Last review Dr ÍOS 25/01/19.