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)

Thrombo-embolic events in coronary and peripheral arteries, and cerebral, pulmonary, portal, hepatic, and deep veins are seen in 27-45% of patients with polycythemia vera (PV). A 79-year-old man was admitted with complaints of pruritus increasing after bath and left upper abdominal pain radiating to left shoulder for two months. On physical examination, ruddy and hyperemic appearances of his face and conjunctiva, tenderness on the left upper quadrant, and splenomegaly were noted. Hemoglobin level was 16.6g/dl, hematocrit 53.8%, white blood cell count 26x10(9)/l, and platelet count 1.032x10(9)/l. Bone marrow aspiration and biopsy revealed hypercellularity, megakaryocytic hyperplasia and dysplasia. The leukocyte alkaline phosphatase score was 190. The levels of serum vitamin B12 and D-dimer were 316 pg/ml and 744 ng/ml, respectively. Arterial O2 saturation was 96%. Red cell mass was measured as 43 ml/kg using radionuclide 51Cr labelled erythrocyte scintigraphy. On cytogenetic analysis, deletion of 20q was found. Computed tomography of whole abdomen showed diffuse splenomegaly and two hypodense areas indicating splenic infarction in 2.5x2 and 3.5x3 cm diameters in subcapsular localization of the spleen. The patient was treated with therapeutic platelet-apheresis, 40 mg/day aspirin, analgesic drugs, and 3g/day hydroxyurea. After 1.5 months, platelet counts dropped to less than 500x10(9)/l and splenic infarcts were not detected on computed tomography. Splenic infarction may be the first evidence of thrombosis in PV. The reduction of platelet counts with platelet-apheresis, anti-platelet drugs, and careful clinical observation may be satisfactory in the treatment of splenic infarction.
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PMID:Recovery of splenic infarction with anti-platelet treatments and platelet-apheresis in polycythemia vera. 1650 86

The chronic myeloproliferative disorders are clonal hematopoietic stem cell disorders of unknown etiology. In one of these (chronic myeloid leukemia), there is an associated pathognomonic chromosomal abnormality known as the Philadelphia chromosome. This leads to constitutive tyrosine kinase activity which is responsible for the disease and is used as a target for effective therapy. This review concentrates on the search in the other conditions (polycythemia vera, essential thrombocythemia and idiopathic mylofibrosis) for a similar biological marker with therapeutic potential. There is no obvious chromosomal marker in these conditions and yet evidence of clonality can be obtained in females by the use of X-inactivation patterns. PRV-1mRNA over expression, raised vitamin B12 levels and raised neutrophil alkaline phosphatase scores are evidence that cells in these conditions have received excessive signals for proliferation, maturation and reduced apoptosis. The ability of erythroid colonies to grow spontaneously without added external erythropoietin in some cases, provided a useful marker and a clue to this abnormal signaling. In the past year several important discoveries have been made which go a long way in elucidating the involved pathways. The recently discovered JAK2 V617F mutation which occurs in the majority of cases of polycythemia vera and in about half of the cases with the two other conditions, enables constitutive tyrosine kinase activity without the need for ligand binding to hematopoietic receptors. This mutation has become the biological marker for these conditions and has spurred the development of a specific therapy to neutralize its effects. The realization that inherited mutations in the thrombopoietin receptor (c-Mpl) can cause a phenotype of thrombocytosis such as in Mpl Baltimore (K39N) and in a Japanese family with S505A, has prompted the search for acquired mutations in this receptor in chronic myeloproliferative disease. Recently, two mutations have been found; W515L and W515K. These mutations have been evident in patients with essential thrombocythemia and idiopathic myelofibrosis but not in polycythemia vera. They presumably act by causing constitutional, activating conformational changes in the receptor. The discovery of JAK2 and Mpl mutations is leading to rapid advancements in understanding the pathophysiology and in the treatment of these diseases.
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PMID:Recent advances in the bcr-abl negative chronic myeloproliferative diseases. 1703 64


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