In patients with myeloproliferative neoplasms (MPNs), including essential thrombocythemia, current studies have demonstrated a JAK2V617F-dependent reactive oxygen species (ROS) elevation partially mediated by a decrease in catalase expression associated with DNA damage. Oxidative stress plays a major role in carcinogenesis as well as in genomic instability, disease progression, myelofibrotic and leukemic transformation, and possibly in the development of vascular events in patients with essential thrombocythemia. Further comprehensive studies are needed to establish the role of oxidative stress in the pathogenesis of essential thrombocythemia, disease progression, vascular complications and whether targeting ROS as a therapeutic option could prevent disease progression and the development of vascular events MPNs patients.
Key words: essential thrombocythemia, oxidative stress, ROS, disease progression, vascular events.
According to the World Health Organization (WHO) classification system for hematopoietic tumors (revised in 2016), essential thrombocythemia (ET), polycythemia vera (PV) and primary myelofibrosis (PMF) are classified as BCR-ABL-1–negative myeloproliferative neoplasms (MPNs). These disorders are characterized by a stem cell-derived clonal myeloproliferation with mutually exclusive „driver“ mutations (JAK2, CALR, and MPL) and a high risk of thrombotic and hemorrhagic complications or leukemic transformation1,2. Essential thrombocythemia is characterized by global myeloid proliferation, especially bone marrow megakaryocyte expansion with large megakaryocytes of mature morphology and hyper-lobulated nuclei, persistent trombocytosis >450×106/L independent of the thrombopoietin level, leukocytosis, splenomegaly, thrombosis or haemorrhage and a possible evolution to secondary myelofibrosis or acute leukemia3.Full text sources