The role of blood component removal in essential and reactive thrombocytosis.

An elevated platelet count is now a common finding in both hospitalized and ambulatory patients with the advent of automated complete blood cell counters. Clinicians may be called upon to make a distinction between a reactive process and a primary hematologic disorder as the cause of a thrombocytosis and to determine whether treatment is indicated. Essential thrombocythemia and other myeloproliferative disorders may present with marked increases in the platelet counts and may be associated with thrombohemorrhagic complications. Reactive thrombocytosis can be caused by iron deficiency and a variety of inflammatory conditions, infections, malignancy, bleeding or hemolysis, splenectomy, and drugs. Acute therapy for all of these disorders has included blood component removal, specifically plateletpheresis. The role of plateletpheresis in current management of thrombocytosis is considered, based on current knowledge of pathophysiology and a review of the literature.