Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0032463 (polycythemia vera)
 3,374 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An increased platelet number in blood depends on a limited spectrum of causes, which aren't always simple to identify. Secondary thrombocytosis is a reactive process in relation with acute or chronic inflammatory diseases, or asplenia. The infrequent inherited thrombocytoses disorders are suspected when similar cases are observed in the same family. However, the most frequent causes of chronic thrombocytosis in adults are the so-called chronic myeloproliferative syndromes (chronic myelocytic leukaemia, polycythemia vera, primary myelofibrosis, essential thrombocytemia), and to a lesser extent, myelodysplastic syndromes. In the course of these disorders, thrombocytosis is often the first recognized abnormality. Chronic myelocytic leukaemia is easily diagnosed owing to the presence of either the Philadelphia chromosome or the BCR-ABL fusion gene product. The next step still relies upon a distinction according to the PVSG or the WHO criteria of Polycythemia Vera (PV) and Idiopathic myelo fibrosis (IMF) to finally confirm genuine Essential Thrombocythemia (ET). The recent description of the V617F mutation of JAK2 in 90% of PV patients, 43 to 67% with IMF and 50% of ET diagnosed according to either the PVSG or the WHO criteria is a definite characteristic of clonality now accessible in haematology practice. However, this mutation is neither specific nor constant in any of the Philadelphia negative myeloproliferative disorders, which outlines the importance of the WHO criteria of megakaryocytic abnormalities on bone marrow biopsy as the hallmark of Ph negative MPDs. The exclusion of PV and of IMF, including pre fibrotic and early fibrotic forms is still required for the diagnosis of "true" ET. Disease stratification and treatment strategy are targeted on the evaluation and prevention of vascular complications. Acute leukaemia or myelodysplasia, and other clonal progressions like myelofibrotic transformation, are infrequent and delayed events. However, according to the present data, the risk of fibrotic progression or of leukaemic transformation is not related to the mutation status of ET patients.
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PMID:[Essential thrombocythemia. Contribution of the V617F JAK2 mutation to the pathophysiology, diagnosis and outcome]. 1807 52

Myeloproliferative disorders (MPDs) are clonal malignancies that arise from hematopoietic progenitors and characterized by overproduction of mature, functional blood cells. These disorders can be broadly characterized into Philadelphia chromosome-positive (Ph(+)) or negative (Ph(-)) genetic groupings. Chronic myeloid leukemia (CML) is a Ph(+) MPD that is defined on the basis of its molecular lesion, the BCR-ABL fusion gene. Inhibitors directed at the constitutive kinase activity of BCR-ABL have been shown to be disease modifying in CML and have dramatically altered the standard of care for this leukemia. The three main Ph(-) MPDs are polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The key features of these Ph(-) MPDs are an increased red blood cell mass in PV, a high platelet count in ET and bone marrow fibrosis in PMF, respectively. These disorders also share many clinical features such as long clinical course, increased risk for thrombosis, hemorrhage and elevated risk of leukemic transformation. Interest in these disorders has been ignited by the recent discovery of activating mutations in the tyrosine kinase gene, JAK2, in the predominance of Ph(-) MPD patients and has highlighted JAK2 as a therapeutic intervention point for drug discovery efforts with selective kinase inhibitors. This review will focus on the comparison of Ph(+) and Ph(-) MPDs, drug discovery and development efforts targeting these disorders, and will assess the new opportunities for targeted therapies for these diseases.
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PMID:Kinase drug discovery approaches in chronic myeloproliferative disorders. 1942 Nov 40

The co-occurrence of JAK2 V617F mutation with BCR-ABL reciprocal translocation is uncommon. We report a 60-year-old man who initially presented with phenotype of polycythemia vera (PV), which evolved into chronic myeloid leukemia and back to PV once treatment with imatinib was commenced. JAK2 V617F mutation and BCR-ABL fusion transcripts were detected in the initial sample. However, JAK2 V617F alleles diminished when BCR-ABL mRNA burden increased and reappeared once the patient was commenced on imatinib. The dynamic interaction between JAK2 V617F and BCR-ABL implies that two independent clones exist with the JAK2 V617F clone only achieving clonal dominance when BCR-ABL positive clones are suppressed by imatinib.
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PMID:A man with concomitant polycythaemia vera and chronic myeloid leukemia: the dynamics of the two disorders. 2004 97

There is no gold diagnostic standard for BCR-ABL fusion gene negative chronic myeloproliterative neoplasm(cMPN). The following detection methods such as comprehensive bone marrow cell morphology, bone marrow pathology, genetic mutation, flow cytometry and immunohistochemical are needed to diagnose the BCR-ABL fusion gene positive cMPN. The JAK2 mutation can be used as a specific diagnostic criteria for polycythemia vera (PV), but there is no specific and sensitive indication for the JAK2 mutation-negative MPN. CALR mutation would be an indication in a certain extent. In this review, the CALR mutation detection, detection mean and its correlation with disease diagnosis and prognosis etc were summarized.
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PMID:[Research Progress on CALR Mutation in the Myeloproliterative Neoplasm -Review]. 2753 10

An important pathogenetic distinction in the classification of myeloproliferative neoplasms (MPNs) is the presence or absence of the BCR-ABL fusion gene, which encodes a unique oncogenic tyrosine kinase. The BCR-ABL fusion, caused by the formation of the Philadelphia chromosome (Ph) through translocation, constitutes the disease-initiating event in chronic myeloid leukemia. The development of successive BCR-ABL-targeted tyrosine-kinase inhibitors has led to greatly improved outcomes in patients with chronic myeloid leukemia, including high rates of complete hematologic, cytogenetic, and molecular responses. Such levels of treatment success have long been elusive for patients with Ph-negative MPNs, because of the difficulties in identifying specific driver proteins suitable as drug targets. However, in recent years an improved understanding of the complex pathobiology of classic Ph-negative MPNs, characterized by variable, overlapping multimutation profiles, has prompted the development of better and more broadly targeted (to pathway rather than protein) treatment options, particularly JAK inhibitors. In classic Ph-negative MPNs, overactivation of JAK-dependent signaling pathways is a central pathogenic mechanism, and mutually exclusive mutations in JAK2, MPL, and CALR linked to aberrant JAK activation are now recognized as key drivers of disease progression in myelofibrosis (MF). In clinical trials, the JAK1/JAK2 inhibitor ruxolitinib - the first therapy approved for MF worldwide - improved disease-related splenomegaly and symptoms independent of JAK2 (V617F) mutational status, and prolonged survival compared with placebo or standard therapy in patients with advanced MF. In separate trials, ruxolitinib also provided comprehensive hematologic control in patients with another Ph-negative MPN - polycythemia vera. However, complete cytogenetic or molecular responses with JAK inhibitors alone are normally not observed, underscoring the need for novel combination therapies of JAK inhibitors and complementary agents that better address the complexity of the pathobiology of classic Ph-negative MPNs. Here, we discuss the role of tyrosine-kinase inhibitors in the current MPN-treatment landscape.
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PMID:Role of tyrosine-kinase inhibitors in myeloproliferative neoplasms: comparative lessons learned. 2757 Apr 58