Myeloproliferative neoplasms: updates on molecular pathophysiology, diagnosis and treatment strategies

Myeloproliferative neoplasms (MPNs) are chronic hematopoietic stem cell disorders, including polycythemia vera, essential thrombocytosis, and primary myelofibrosis. The JAK2V617F mutation was identified in 2005, followed by the discovery of the JAK2 exon12, MPNW515 mutation, and CALR mutation. About 90% of patients with BCR/ABL negative MPNs have been shown to have one of these driver mutations. In addition, mutations in epigenetic regulators and RNA splicing genes were found to co-exist with driver mutations and to play critical roles in the disease progression of MPNs. Currently, evaluations of these gene mutations are essential for the diagnosis of MPNs, and are also necessary for estimating the clinical course and the risk of disease progression. Guidelines for the management of MPNs were based on the results of large clinical trials. Furthermore, recent advancements in understanding the pathogenesis of MPNs are anticipated to promote the development of MPN-targeted therapies such as JAK2 inhibitors. Clinical trials for patients with PMF and PV have confirmed the efficacies of JAK2 inhibitors.