Thrombotic, Vascular, and Bleeding Complications of the Myeloproliferative Neoplasms.

Thrombotic, vascular, and bleeding complications are the most frequent causes of morbidity and mortality in myeloproliferative neoplasms (MPNs). The interplay and reciprocal amplification between two factors are considered to lead to thrombosis in MPNs: (1) circulating blood cell-intrinsic abnormalities caused by an MPN driver mutation in their hematopoietic progenitor/stem cells, interacting with vascular endothelial cells, show prothrombotic and proadhesive phenotypes; and (2) a state of usually subclinical systemic inflammation that fuels the thrombotic tendency. Prevention and treatment require maintenance of hematocrit less than 45% and cytoreductive therapy in patients with a high risk for thrombotic and vascular complications.