Thrombotic Thrombocytopenia Purpura (TTP) is a rare disorder of the blood coagulation system and is considered a true medical emergency.

TTP is characterised into acquired (idiopathic) and congenital (familial) and affects 4-6 people per million, affecting women more than men with a peak incidence in your forties.

TTP causes extensive clots (microscopic thromboses) to form in small blood vessels throughout the body (thrombotic microangiopathy). TTP is one of the microangiopathic haemolytic anaemias, and is characterised by the presence in the plasma of large von Willebrand Factor (VWF) strings. VWF is a large protein involved in blood clotting.

Most cases of TTP arise from lack of an enzyme known as ADAMTS 13, which is responsible for breaking down large strings of VWF into smaller units, which then reduces the small blood vessel clots. Often the ADAMTS 13 stops working because your body makes antibodies to it.