Australian Red Cross Blood Service

The pathogenesis of this condition, also called TTP, is likely to be multifactorial.

The haemostatic defect includes thrombocytopenia associated with a microangiopathic haemolytic anaemia and other clinical features.

Management includes plasma exchange using either fresh frozen plasma or cryodepleted plasma as replacement fluids.

Both are effective, however, at the present time there is insufficient data to show whether fresh frozen plasma or cryodepleted plasma is more efficacious as first line therapy. Clinical trials are currently in progress.

Large daily doses are needed, usually in the order of 3 L/day (one plasma volume in an adult patient).

All forms of plasma contain the metalloproteinase enzyme ADAMTS13, which may be deficient or inhibited in TTP.

ADAMTS13 contributes to degrading the ultra-large multimers of von Willebrand factor that cause the excessive platelet activation and consumption.

Platelet transfusions are generally contraindicated.