Journal: Seminars in thrombosis and hemostasis
This review article focuses on thrombotic and bleeding complications in myeloproliferative neoplasms (MPNs) and their implications for management.
Key points:
- Spectrum of vascular events
- Venous: deep vein thrombosis, pulmonary embolism, and “unusual site” thromboses (e.g., splanchnic, cerebral venous).
- Arterial: ischemic stroke, myocardial infarction, and peripheral arterial thrombosis.
- Bleeding: increased risk of major hemorrhage, often coexisting with thrombotic risk.
- Pathophysiology
- Pro-thrombotic drivers include JAK2-driven clonal hematopoiesis, elevated hematocrit, leukocytosis, platelet activation, endothelial dysfunction, and chronic inflammation.
- Bleeding risk is promoted by extreme thrombocytosis, acquired von Willebrand syndrome, and the use of antiplatelet/anticoagulant therapies.
- Clinical presentation
- Thrombosis can be the first clinical manifestation and may precede the formal diagnosis of an MPN, particularly at unusual venous sites.
- Management must carefully balance prevention of recurrent thrombosis against bleeding risk.
- Current management strategies
- Antithrombotic therapy: low-dose aspirin, vitamin K antagonists, and direct oral anticoagulants are used, tailored to individual risk profiles and event type.
- Cytoreduction: hydroxyurea, anagrelide, interferon, and JAK inhibitors are central for controlling blood counts and reducing vascular risk.
- Unmet needs and future directions
- Despite current strategies, recurrent thrombosis and major bleeding remain frequent.
- The authors emphasize the need for improved risk stratification models incorporating molecular biomarkers, measures of inflammation, and vascular-specific endpoints.
- Future work should aim at more personalized preventive strategies and exploration of novel therapeutic targets.