Chronic relapsing thrombotic thrombocytopenic purpura: three case reports and update of the pathogenesis and therapeutic modalities.

Chronic relapsing thrombotic thrombocytopenic purpura (CRTTP) is the rarest type of TTP, usually presenting in childhood. The aetiology is still not fully explained. The disorder is associated with the presence in plasma of unusually large von Willebrand factor (UlvWF) multimers that are especially prominent between episodes. CRTTP can be prevented by periodic plasma transfusions. We report three children with congenital CRTTP who have been successfully treated and maintained in prolonged remission by the prophylactic use of fresh frozen plasma without concurrent plasmapheresis. Two of the patients are sibs.