Myeloproliferative neoplasms (MPNs) are associated with risk of thrombosis and bleeding. Thrombosis can be the first manifestation before an MPN diagnosis. The association became more fraught with the advent of COVID-19, which is associated with a high rate of thromboembolism, bleeding, and death.
A group of investigators assessed the available research on the clinical features of patients with Philadelphia-negative MPN during the COVID-19 pandemic suggesting treatment guidance. Their findings were published in Current Hematologic Malignancy Reports.
The investigators reviewed some studies, such as one from the European Collaboration on Low-dose Aspirin (ECLAP), for information on thrombosis in MPN without COVID-19 for context. They then reviewed other research, such as a study from the European LeukemiaNet (ELN) with 175 patients with MPN who contracted COVID-19 during the early months of the pandemic in 2020.
“When compared with the general population with COVID-19, the mortality ratio in the ELN study was at least two to three times higher than the mortality rates reported by Johns Hopkins in the same period of the first wave of the pandemic and comparable to that reported in other hematologic malignancies collected in the same period,” the investigators stated.
They also noted that in univariate analysis, patients with primary myelofibrosis (PMF) had a higher risk of mortality (48%) compared with patients with essential thrombocythemia (ET; 25%) and those with polycythemia vera (PV; 19%).
Based on information from the European LeukemiaNet research on incidence and risk factors of thrombosis and bleeding in MPN, “the probability of total thrombosis progressively increased in the first month after a COVID-19 diagnosis and reached 8.5% after 60 days of follow-up.”
The investigators also noted that caution should be used with anticoagulants. Although limited, research currently suggests that the empiric use of full-dose low molecular weight heparin (LMWH) as prophylaxis to prevent venous thromboembolism (VTE) is discouraged even for critically ill MPN patients with COVID-19, unless they are participating in a clinical trial.
The American Society of Hematology (ASH) is maintaining a resource for hematology clinicians to optimize the management of MPN patients with COVID-19.
The investigators concluded that their perspective dovetails with the ASH recommendations to treat MPN patients at home with recommended routine prophylaxis. However, hospitalized patients may need LMWH at intermediate/therapeutic doses instead of anti-vitamin K antagonists or direct oral anticoagulants prescribed pre-COVID.
Barbul T, De Stefano V. Philadelphia-negative myeloproliferative neoplasms around the COVID-19 pandemic. Curr Hematol Malig Rep. Published online September 29, 2021. doi:10.1007/s11899-021-00647-z