Therapeutic plateletpheresis in thombocythemia.

Patients with myeloproliferative thrombocythemia have usually been managed with chemotherapy. Generally, removal of platelets from such patients has been performed intermittently to lower the platelet mass rapidly when neurologic or hemorrhagic complications were manifest or concurrently with the initiation of chemotherapy. A platelet count of 1,000,000/microliter or less was maintained by the use of repeated plateletpheresis over a period of three months in a patient with essential thrombocythemia, who had frequent syncopal episodes. A second patient with secondary thrombocytosis, who sustained two cerebrovascular accidents, underwent intermittent plateletpheresis over a 22-day period until her underlying disorder improved. It is concluded from the experience, combined with that of others, that plateletpheresis is not only a life-saving procedure in an acute episode but may also be used to maintain a lowered platelet count over a prolonged period in selected patients with primary thrombocythemia, in whom chemotherapy cannot be undertaken, and in symptomatic patients with secondary thrombocythemia.