What is the efficacy of plasma exchange in the treatment of TTP?
Plasmapheresis may replenish the levels of ADAMTS-13 protease that is deficient in some cases of TTP. Duration of daily therapeutic plasma exchange (TPE) to achieve a durable remission (e.g., platelet count >150,000 for 3 days and lactate dehydrogenase (LDH) near normal and no neurologic deficit, if initially present) is variable. There is no evidence for a beneficial role of plasmapheresis in patients with TTP secondary to cancer, chemotherapy, or bone marrow transplantation.