Thrombocytemia

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Bleeding and thrombosis are long recognized complications of myelofibrosis (MF) and contribute significantly to its morbidity and mortality. However, so far, few studies have evaluated the frequency of these events, their characteristics, and their prognostic impact. Based on these studies, thrombotic events in MF are about as common as in essential thrombocytemia (ET) but less common than in polycythemia vera (PV), while bleeding events are relatively more common in MF than in ET or PV. The emergence of the concept of prefibrotic primary MF (PMF), which is associated with a higher frequency of thrombohemorrhagic complications than ET, and the growing evidence that prefibrotic PMF may also have a different thrombotic and bleeding risk profiles than fibrotic (overt) PMF have emphasized the need for a reappraisal of the risk of thrombosis and hemorrhage in patients with MF...

Primary myelofibrosis (PMF) is a myeloproliferative neoplasm characterized by hyperplastic megakaryopoiesis and myelofibrosis. We recently described the upregulation of MAF (v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog) in PMF CD34+ hematopoietic progenitor cells (HPCs) compared to healthy donor. Here we demonstrated that MAF is also upregulated in PMF compared with the essential thrombocytemia (ET) and polycytemia vera (PV) HPCs. MAF overexpression and knockdown experiments shed some light into the role of MAF in PMF pathogenesis, by demonstrating that MAF favors the megakaryocyte and monocyte/macrophage commitment of HPCs and leads to the increased expression of proinflammatory and profibrotic mediators...

In this brief review, we have examined some clinical conditions that result to be associated to an altered hemorheological profile and at times accompanied by skin ulcers. This skin condition may be observed in patients with the following condtions, such as primary polycythemic hyperviscosity (polycythemia, thrombocytemia) treated with hydroxyurea, primary plasma hyperviscosity (multiple myeloma, cryoglobulinemia, cryofibrinogenemia, dysfibrinogenemia, and connective tissue diseases), primary sclerocythemic hyperviscosity (hereditary spherocytosis, thalassemia, and sickle cell disease)...

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Myelofibrosis (MF) is the most severe among the classical Philadelphia-negative myeloproliferative neoplasms that also include essential thrombocytemia and polycythemia vera. Myelofibrosis is characterized by numerous genetic lesions, often variously associated with each other, and by an aggressive clinical phenotype leading to severely reduced survival. Also, the inflammatory microenvironment plays a key role in disease initiation and progression. Because of the complexity of its pathogenesis and the variability of clinical features, MF is a disease that requires a personalized approach and remains orphan of curative treatments besides allogeneic transplantation...

A deeper understanding of the molecular events driving megakaryocytopoiesis and thrombopoiesis is essential to regulate in vitro and in vivo platelet production for clinical applications. We previously documented the crucial role of PKCε in the regulation of human and mouse megakaryocyte maturation and platelet release. However, since several data show that different PKC isoforms fulfill complementary functions, we targeted PKCε and PKCδ, which show functional and phenotypical reciprocity, at the same time as boosting platelet production in vitro...

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INTRODUCTION: β-Catenin is a multifunctional protein that acts as a central effector molecule in the Wnt signaling pathway. Aberrant activation of the Wnt/β-catenin signaling pathway causes various diseases including cancer. In this study we evaluated β-catenin expression in bcr/abl-negative myeloproliferative neoplasms (MPNs). MATERIALS AND METHODS: The expression of β-catenin was evaluated in bone marrow using immunohistochemical methods in 66 patients with bcr/abl-negative myeloproliferative neoplasms (MPNs) and in 30 healthy control subjects...

AIM: To analyze current practices in Bulgaria regarding antithrombotic medication (AM) during pregnancy, and to compare them with the ones recommended in literature. MATERIALS AND METHODS: In 84 pregnant women who were low dose aspirin (LDA) or/and low molecular weight heparin (LMWH) or unfractionated heparin (UH), data about AM were collected and analyzed. A descriptive analysis was performed of the indications for AM, its type, the applied doses and therapeutic regimens...

Budd-Chiari syndrome is a rare condition caused by interrupted hepatic venous outflow in the hepatic veins, inferior vena cava, or right atrium. Reports from the literature have delineated on focal nodular hyperplasia (FNH)-like lesions in association with Budd-Chiari Syndrome. To our knowledge, there are no reports about true FNH lesions in patients with Budd-Chiari Syndrome. Focal nodular hyperplasia develops in disorders with aberrant circulation and vasculature. We report a case of Budd-Chiari syndrome in association with large solitary FNH in a 22-year-old man who was referred to our institution with sudden intermittent right upper quadrant abdominal pain, vomiting, diarrhea with pale stool, decreased appetite, dark urine, and abdominal distention for 15 days...

BACKGROUND: A number of studies showed that the JAK2 V617F mutation increases the thrombotic risk in patients with myeloproliferative disorders (MPN) while others did not reveal this correlation, and it is unknown whether inherited thrombophilia is an additive risk factor in mutated subjects. Our aim was to clarify the contribution of JAK2 V617F to a hypercoagulable state, as well as its interaction with other thrombophilic factors in patients with thrombosis and myeloproliferative disorders...

Essential thrombocytemia--a classic myeloproliferative neoplasm characterized by persistent thrombocytosis--may associate both thrombotic and hemorrhagic events, as well as platelet dysfunction. Of all myeloproliferative neoplasms, essential thrombocytemia is more likely to be associated with pregnancy, because of a higher comparative incidence in younger patients. This association significantly increases the risk of pregnancy loss and of various pregnancy complications. We present a case of early severe preeclampsia with a critical and unusual evolution and life-threatening complications...

BACKGROUND: Vascular events represent the most frequent complications of thrombocytemias. We aimed to evaluate their risk in the WHO histologic categories of Essential Thrombocytemia (ET) and early Primary Myelofibrosis (PMF). METHODS: From our clinical database of 283 thrombocytemic patients, we selected those with available bone marrow histology performed before any treatment, at or within 1 year from diagnosis, and reclassified the 131 cases as true ET or early PMF, with or without fibrosis, according to the WHO histological criteria...

Cerebral venous thrombosis (CVT) is a rare origin of stroke, the clinical presentation and etiologies vary. The prognosis is shown to be better than arterial thrombosis. Magnetic Resonance Imaging (MRI) and MR Venograpgy (MRV) are currently important tools for the diagnosis. We studied 30 cases of CVT diagnosed in the department of neurology at the University Hospital of Fez (Morocco). Patients diagnosed with CVT signs between January 2003 and October 2007 were included in the study. Cerebral CT-scan was performed in 27 cases (90%) while the MRI examination was done in 18 patients (67%); and most patients (90%) received anticoagulant therapy...

Cerebral venous thrombosis (CVT) is a rare origin of stroke, the clinical presentation and etiologies vary. The prognosis is shown to be better compared to arterial thrombosis. Magnetic Resonance Imaging (MRI) and MR Venograpgy (MRV) are currently important tools for the diagnostic. We studied 30 cases of CVT diagnosed in the department of neurology of the University Hospital of Fez (Morocco). Patients diagnosed with CVT signs between January 2003 and October 2007 were included in the study. Cerebral CT-scan was performed in 27 cases (90%) while the MRI examination was done in 18 patients (67%); and most patients (90%) received anticoagulant therapy...

Megakaryopoiesis is a 2-step differentiation process, regulated by thrombopoietin (TPO), on binding to its cognate receptor myeloproliferative leukemia (MPL). This receptor associates with intracytoplasmic tyrosine kinases, essentially janus kinase 2 (JAK2), which regulates MPL stability and cell-surface expression, and mediates TPO-induced signal transduction. We demonstrate that JAK2 and MPL mediate TPO-induced proliferation arrest and megakaryocytic differentiation of the human megakaryoblastic leukemia cell line UT7-MPL...

Aspirin is a cornerstone in the prevention of ischemic events and guidelines usually recommend a once-daily dosing. This dosing is based at least in part on the platelet renewal rate, which is of only 10-15% a day. A once-daily dosing is now challenged by several studies demonstrating that when platelet turnover is increased, such as in patients with diabetes or essential thrombocytemia, the inhibition of platelet function provided by aspirin is no longer homogeneous between dosing with a significant recovery of platelet function within a day that is blunted by a twice-daily dosing...

AIM: It is known that thrombocytosis is closely related to vascular complications and particularly thrombosis in essential thrombocytemia (ET) cases. The aim of this study is to investigate a possible correlation between adhesion molecules and vascular attacks as well as the relation of these molecules to the platelet count. METHODS: The study group consisted of 30 ET patients and 30 healthy controls subjects. Serum intracellular adhesion molecule-1 (ICAM-1), serum vascular adhesion molecule-1 (VCAM-1) and serum E-selectin levels were determined by ELISA method according to manufacturer's instructions...

JAK-STAT signaling through the JAK2V617F mutation is central to the pathogenesis of myeloproliferative neoplasms (MPN). However, other events could precede the JAK2 mutation. The aim of this study is to analyze the phenotypic divergence between polycytemia vera (PV) and essential thrombocytemia (ET) to find novel therapeutics targets by a proteomic and functional approach to identify alternative routes to JAK2 activation. Through 2D-DIGE and mass spectrometry of granulocyte protein from 20 MPN samples, showed differential expression of HSP70 in PV and ET besides other 60 proteins...