TF and TFPI in myeloproliferative neoplasms — a preliminary study

Abstract

Introduction. Haemostatic disturbances such as thrombosis or diathesis are frequent complications in patients with myeloproliferative neoplasms (MPNs). The purpose of this study was to evaluate the concentration of tissue factor (TF), tissue factor pathway inhibitor (TFPI), and thrombin–antithrombin (TAT) complexes in patients with MPNs.

Patients and methods. The study involved 43 patients with MPNs (mean age 60.5 years), including 16 patients with essential thrombocythaemia, eight with polycythaemia vera, ten with chronic myeloidleukaemia, and nine with primary myelofibrosis. The control group consisted of 30 healthy volunteers who were age- and sex-matched. TF, TFPI and TAT complexes concentration were measured using the immunoenzyme method.

Results. TF and TAT complex concentrations were significantly higher, but the TFPI concentration was lower, in the total study group compared to the control group. TF concentration in each of the subgroups was significantly higher than in the control group. TFPI concentration was significantly lower in essential thrombocythaemia and polycythaemia vera than in controls. In addition, the concentration of TAT complex in patients with chronic myeloid leukaemia was significantly higher than in the control group.

Conclusions. Elevated TF levels and decreased TFPI levels in patients with essential thrombocythaemia and polycythaemia vera indicate the activation of blood coagulation process depending on the TF (an extrinsic pathway). These patients represent a group at high risk of thrombotic complications.