The Clinical Significance of Circulating Microparticles Concerning Thrombosis in BCR/ABL1-negative Myeloproliferative Neoplasms

Background/Aim: This work aimed to prospectively evaluate the clinical significance of circulating microparticles (MPs) in relation to thrombotic risk factors and thrombotic complications in patients with BCR/ABL1-negative myeloproliferative neoplasms (MPN). Patients and Methods: In a cohort of 206 patients with MPN, MPs' procoagulant activity was measured by the Zymuphen functional assay in 429 samples, while plateletand erythrocyte-MPs were enumerated by flow cytometry in 558 samples. Results: MPN patients had higher MP levels than the control group. The levels of MPs were higher in male patients, smokers, and those who were older than 60 years, and in the presence of JAK2(V)(617F) mutation, history of thrombosis, platelets >400 x 10(9)/l, hematocrit >45%, or leukocytes >10x 10(9)/l. Cytoreductive treatment reduced MP levels, with anagrelide being associated with lower MP levels than hydroxyurea. Conclusion: The relationship with thrombotic risk factors indicates a possible role of MPs in the complex thrombotic mechanism, though cytoreductive treatment seems to affect this role through reducing MP levels.