Global tests in patients with Ph-negative myeloproliferative neoplasms

Abstract

Introduction: A frequent clinical manifestation of Ph-negative myeloproliferative neoplasms (MPN) is the development of thrombosis. To identify the state of hypercoagulation it is relevant and promising to introduce global tests for evaluating the hemostasis — the thrombin generation test (TGT) and thromboelastography (TEG). Aim: to evaluate the parameters of thrombin generation and thromboelastography in patients with Ph-negative MPN. Material and methods. In total, 62 patients with MNP were included in the study: 27 with polycythemia vera (PV), 14 with essential thrombocythemia (ET) and 21 with primary myelofibrosis (PMF). The control group included 55 practically healthy individuals, comparable in gender and age (19 people in the study of TEG, 36 people in the study of TGT). The TEG was performed using a “TEG 5000” thromboelastograph. TGT was measured with Calibrated Automated Thrombinography. Results: Ly30 and Ly60 in TEG in patients were significantly lower (0.35 (0.20–0.48), 0.00 (0.00–0.40) and 0.00 (0.00 — 0.43) and 3.15 (2.45–3.60), 1.25 (0.10–3.58) and 0.60 (0.00–3.05) respectively), than in the control (1.60 (1.05–2.75) and 6.20 (4.15–8.30), respectively), which indicates the ineffectiveness of fibrinolysis. The values of MA and G in patients with ET and PV significantly exceeded the control (69.15 (67.98–70.78) mm and 65.20 (59.65–63.83) mm versus 62.00 (57.75–6.75) mm and 11.20 (10.60–12.15) din/cm2 and 9.40 (7.40–11.60) din/cm2 versus 8.20 (6.85–8.75) din/cm2, respectively. The most pronounced change in sensitivity to TM was observed in patients with ET (27.94 (17.35–43.58) % and 13.29 (-3.48–23.60) %, respectively; p < 0.05). A significant decrease in ETP was observed in patients with PV and PMF. Conclusion. The study of hemostasis in patients with MPN using TEG and TGT revealed the presence of multidirectional changes associated with the disease. The TEG showed that an increase in the time required for the onset of fibrin formation is combined with increased clot strength and inhibited fibrinolysis, which are risk factors for the development of thromboembolic complications. The study of TGT determined a decrease in the quantitative characteristics of thrombin generation and at the same time the failure of the anticoagulant system of protein C, leading to the development of hypercoagulation.