JAK2 mutation status, hemostatic risk factors and thrombophilic factors in essential thrombocythemia (ET) patients

Abstract

The recently discovered JAK2 V617F point mutation, found in 50-60% of ET patients, has been reported to be associated with a higher risk of thrombotic events. In this study, we explored if JAK2 V617F mutation, or coexisting thrombophilic and hemostatic risk factors, contributed to these complications. We examined 32 patients with ET, and looked for pathogenetic JAK2 V617F mutation and prothrombotic genes mutations: factor V Leiden, prothrombin and MTHFR. We also evaluated plasma levels of fibrinogen, factors VIII and XII, AT, protein C, protein S and serum level of homocysteine. Urokinase concentration was assessed in patients' plasma as well as platelet lysates. There was no difference in the number of thrombotic complications between ET patients with and without JAK2 mutation. However, we found a number of thrombophilic and hemostatic risk factors that could contribute to thrombotic complications in ET patients. (Folia Histochemica et

Impact of JAK2 V617F Mutation on Hemogram Variation in Patients with Non-Reactive Elevated Platelet Counts

“…Interestingly, this phenomenon existed not only in ET patients but also in all of patients with non-reactive elevated platelet count. Our results support the hypothesis that JAK2 V617F mutation activated TPOR pathway and led to hyperplasia of megakaryocytic progenitor cells [19].…”

“…JAK2 V617F increases Bcl-xL expression in hematopoietic progenitor cells [17] and contributes to the development of erythrocytosis [18]. In addition, JAK2 V617F induces abnormal activation of thrombopoietin receptor (TPOR) and granulocyte colony-stimulating factor receptor (G-CSFR) pathway, leading to hyperplasia of megakaryocytic and granulocytic progenitor cells [19]. Because JAK2 V617F mutation promotes proliferation of multiple cell lineages, patients with such mutation exhibit increased numbers of mature and immature cells in peripheral blood.…”

Evaluation of clinical and laboratory findings with JAK2 V617F mutation as an independent variable in essential thrombocytosis

“…Since large platelet represents new and immature platelet, particular studies indicated that JAK2 V617F mutation was significantly associated with increase of immature platelets [15,29]. It was supposed that JAK2 V617F may promote thrombopoiesis and caused to hyperplasia of megakaryocytic progenitor cells in the bone marrow [30].…”

Preservation of small bowel with the selective use of heparin and second look laparotomy in acute mesenteric ischaemia: A case report

“…3 Mutations in JAK2 are found in approximately 50-60% of cases of essential thrombocythaemia. 4 The clinical manifestations of essential thrombocythaemia result from platelet activation, 5 hyperviscosity, tissue hypoxia and vascular occlusion 6 with arterial thrombosis occurring more commonly than venous thrombosis. 7 Mesenteric and portal vein thrombosis are recognised rare complications of myeloproliferative disease.…”