Angiogenic parameters and the risk factors for thrombosis in polycythemia vera

Abstract

Aim: The assessment of angiogenic parameters in so-called “liquid tumors”, such as myeloproliferative neoplasms, remains an open clinical issue. The aim of the study is to evaluate the concentration of vascular endothelial growth factor (VEGF-A) and soluble receptors sVEGFR-1 and sVEGFR-2 in relations to risk factors of thrombosis in patients with polycythemia vera (PV). Material/Methods: A total of 45 patients suffering from newly diagnosed PV and 30 healthy volunteers were enrolled into the study. Polycythemia vera was diagnosed according to the WHO (2008) criteria. In the citrated plasma samples VEGF-A, sVEGFR-1 and sVEGFR-2 were measured using ELISA tests. Results: VEGF-A concentration was three-fold higher and sVEGFR-2 significantly lower in PV patients as compared to the control group. VEGF-A concentration was significantly higher in PV patients with JAK2V617F mutation, as compared to patients without this mutation. SVEGFR-1 and sVEGFR-2 concentrations were similar in the analyzed subgroups. In PV patients with an increased number of white blood cells (WBCs), the above upper reference value (≥10 G/l), VEGF-A concentration was two-fold higher than in patients with WBCs number <10 G/l. However, sVEGFR-1 and sVEGFR-2 concentrations did not differ between the analyzed subgroups. Analysis of correlations revealed only one relation between VEGF-A and WBCs number. Conclusions: Increased VEGF-A and decreased sVEGFR-2 concentrations in polycythemia vera patients as compared to the control group indicate an intensification of the process of angiogenesis. A higher concentration of VEGF-A in PV patients with leukocytosis and a positive correlation between WBCs number and VEGF-A reflect the potential role of VEGF-A in the pathogenesis of thrombotic complications in hypercoagulable state in PV patients.