Control of thrombocytosis by plateletpheresis using a cell separator.

Three patients with marked thrombocythaemia secondary to myeloproliferative disorders were treated with plateletpheresis using an Aminco cell separator and myelosuppressive agents. Immediate control of the raised platelet count was achieved by plateletpheresis and long-term control by the concomitant cytotoxic therapy. The indications for plateletpheresis in patients with marked thrombocytosis are discussed.