Thrombocytosis and Thrombosis

Abstract

The aim of this review is to discuss current diagnostic approaches to, and classification of, patients presenting with thrombocytosis, in light of novel information derived from the discovery of specific molecular abnormalities in chronic myeloproliferative disorders (CMPD), which represent the most common cause of primary thrombocytosis. The JAK2V617F and the MPLW515L/K mutations have been found in patients with essential thrombocythemia, polycythemia vera, and primary myelofibrosis, and less frequently in other myeloproliferative disorders complicated by thrombocytosis. However, neither mutation is disease specific nor is it universally present in patients with elevated platelet counts due to a CMPD; therefore, distinguishing between reactive and primary forms of thrombocytosis, as well as among the different clinical entities that constitute the CMPD, still requires a multifaceted diagnostic approach that includes as a key step the accurate evaluation of bone marrow histology. The role of elevated platelet counts in thrombosis, which represent the predominant complication of CMPD,significantly affecting prognosis and quality of life as well as, paradoxically, in the pathogenesis of the hemorrhagic manifestations, will be discussed. Established and novel potential risk factors for thrombosis, including the clinical relevance of the JAK2V617F mutation, and current management strategies for thrombocytosis are also briefly discussed.

Neurological disorders in essential thrombocythemia

“…In particular, a high platelet count was not associated with the occurrence of neurological symptoms, in agreement with studies assessing risk factors for vascular events in ET. 24 Of note, Kesler reported a significant predominance of females in patients with neurological symptoms, 17 but this observation was not confirmed in our series.…”

Thrombocytosis and leukocytosis interaction in vascular complications of essential thrombocythemia

“…2 The novel finding is the inverse relationship between platelet count and thrombosis. Similar results were obtained in an analysis of 1638 polycythemia vera (PV) patients enrolled in the European Collaboration on Low-Dose Aspirin in Polycythemia Vera study.…”

“…1 Recently, leukocytosis and JAK2 V617F mutation have been proposed as disease related prognostic factors. 2 In contrast, the link between thrombocytosis and vascular complications remains uncertain. 3 Nevertheless, expert-produced guidelines recommend that therapy in ET should be aimed at correcting thrombocytosis.…”

Reactive thrombocytosis resulting from frequent blood donations as an extremely rare cause of ST Segment Elevation Myocardial Infarction in the case of a 19-year-old male

“…Thrombocytosis is the second most common cause of death in patients with polycythaemia vera (PV) or essential thrombocytosis (ET) [6]. The available data show that the frequency of cardiovascular complications caused by ET varies from 4%-21%.…”