Thrombotic thrombocytopenic purpura

Keywords: TTP


Appropriate Tests


TTP is a rare disorder, caused by a congenital or acquired deficiency of the Von Willebrand factor (VWF) cleaning protease ADAMTS-13. There is a response to plasma exchange (in congenital disorders) and to plasmapheresis (in acquired disorders). There is a high mortality rate untreated. Its hallmarks are thrombocytopenia (often severe), red cell fragmentation and evidence of haemolysis, with variable CNS and renal dysfunction. Treatment is a medical emergency.

Full blood count, Blood film (red cell fragmentation); Creatinine, Urea, Electrolytes. Urine - Urinalysis, microscopy. ADAMTS-13 activity assay is performed by some laboratories. 

See also Haemolytic uraemic syndrome

Microangiopathic haemolysis

Increased Reticulocyte count, Bilirubin and Lactate dehydrogenase are expected with anaemia.


Variable but often severe.


Variable at presentation and may be absent. See also Pyrexia of unknown origin

Fluctuating neurological signs


Renal impairment, including


  • Proteinuria


  • Haematuria


  • Renal failure - acute


Go Back

Page last updated:

Copyright © 2020 RCPA. All rights reserved.