[New aspects of myeloproliferative neoplasms: COVID-19 and myeloproliferative neoplasms].

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has made the management of coronavirus disease-2019 (COVID-19) in patients with hematological disorders a new and important theme for hematologists. Patients with myeloproliferative neoplasms (MPNs) are susceptible to SARS-CoV-2 and are at an increased risk of death after the onset of COVID-19. Thus, infection prevention measures, including vaccination for all patients, are important. Patients with MPNs who have COVID-19 have a poor prognosis, as do patients with other hematological malignancies. The thrombogenic characteristics of MPNs increase the risk of venous thrombosis due to COVID-19. Anticoagulant therapy is adjusted according to the risk of each case after COVID-19 onset. However, thrombosis occurs at a high rate, especially in patients with essential thrombocythemia. Additionally, patients with myelofibrosis have an increased risk of death and bleeding. Ruxolitinib treatment poses a risk of SARAS-CoV-2 infection, and its abrupt discontinuation after infection is associated with an increased risk of death. The emerging evidence of COVID-19 has been quickly reflected in the available treatment recommendations and guidelines.