Activation of Extrinsic Coagulation Pathway in Myeloproliferative Neoplasms – Preliminary Report

The aim of the study was to assess the activation of extrinsic blood coagulation pathway, based on the TF and TFPI measurements in patients with MPNs. The study group consisted of 17 patients with MPNs (mean age 59 years). The control group was made of 30 healthy volunteers (mean age 52 years). In blood samples tissue factor TF, tissue factor pathway inhibitor (TFPI), thrombin-antithrombin complexes (TAT) concentration and antithrombin (AT) activity were determined. The present study showed a significantly higher level of tissue factor and decreased TFPI concentration in patients with polycythemia vera, essential thrombocythemia and primary myelofibrosis. Conclusions: 1. The results showed that in all groups of patients with MPNs an extrinsic activation of coagulation, resulting in a high concentration of TF in the blood of these patients, occurs. 2. It seems that in patients with ET, PMF and PV, an extrinsic activation of coagulation is inhibited by TFPI inhibitor as evidenced by its reduced concentration observed in the blood of these patients (the result of extrinsic consumption in the track).