Polycythemia vera (PV) is a clonal myeloproliferative disease characterized by an erythroid dominant trilineage proliferation of hematopoietic precursor cells. Classified as a chronic myeloproliferative disease, PV represents a histopathologic spectrum of 2 recognized stages, the polycythemic and postpolycythemic phase. The clinical manifestations of hemorrhage, thrombosis, and increased red cell mass are directly related to primary bone marrow dysfunction. Prognosis is strongly associated with thrombosis risk and disease progression; thus, treatment is directed toward minimizing coagulopathic complications and preventing leukemic transformation. Recently, a specific point mutation in the Janus kinase 2 (JAK2) gene was described in a majority of PV patients. The potential diagnostic and/or prognostic value of JAK2V617F is discussed.
To review important developments from the recent and historical literature. Modern diagnostic criteria and emerging molecular findings are emphasized.
A comprehensive review was performed of the relevant literature indexed in PubMed (National Library of Medicine) and referenced medical texts.
Modified clinical, histologic, and laboratory criteria have clarified the diagnosis of PV. Also, continuing studies on the recently discovered JAK2V617F gene mutation may significantly improve our understanding of PV pathogenesis and facilitate its medical management.
[Show abstract][Hide abstract] ABSTRACT: We report a JAK2 V617F-negative case of polycythemia vera with two acquired balanced X-autosome translocations and no history of previous exposure to chemo/radiotherapy. The patient's first clone carried a novel translocation t(X;15)(q24;q13) as a sole abnormality. The second clone exhibited an additional translocation, t(X;20)(q13;q13.3), which is a rare recurrent abnormality in myeloid malignancies. This is the first report of a hematological disorder with both X chromosomes being translocated. Late replication studies revealed a switch in X-inactivation from the X chromosome involved in t(X;15) (first clone) to the X chromosome involved in the t(X;20)(q13;q13.3) (second clone). The inactivation of the translocated X chromosomes could provide potential for the inactivation of the adjacent autosomal regions, resulting in epigenetic gene silencing.
Leukemia Research 08/2007; 31(7):1009-14. DOI:10.1016/j.leukres.2006.11.014 · 2.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A 25-year-old man developed prolonged loss of vision in the left eye. Examination revealed that visual acuity was 20/20 in the right eye and 10/20 in the left eye, with a left relative afferent pupillary defect. Fundoscopy showed multiple cotton wool spots in the left whole retina with normal optic disc. Fluorescein angiography (FA) revealed markedly delayed arterial, venous and recirculation time in the left eye without retinal arterial or venous occlusion. Bone marrow aspirate confirmed polycythemia vera. After the patient underwent phlebotomy, his visual acuity markedly improved and cotton wool spots in the retina disappeared. On follow-up FA, delayed arterial and venous filling, and recirculation time also became normalized. This case suggests that ischemic damage of the retina due to the great viscosity of blood may be a possible mechanism of monocular visual loss in polycythemia vera. Clinicians should be aware that isolated monocular visual loss may be an initial manifestation of polycythemia vera, since if untreated, polycythemia vera carries a high risk of permanent complications due to intravascular thrombosis.
Journal of the Neurological Sciences 08/2007; 258(1-2):151-3. DOI:10.1016/j.jns.2007.03.014 · 2.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chorea is a hyperkinetic movement disorder characterised by excessive spontaneous movements that are irregularly timed, randomly distributed and abrupt. In this article, the authors discuss the causes of chorea, particularly Huntington's disease and the genetic syndromes that may resemble it, including HDL1-3, inherited prion disease, spinocerebellar ataxias 1, 3 and 17, neuroacanthocytosis, dentatorubro-pallidoluysian atrophy (DRPLA), brain iron accumulation disorders, Wilson's disease, benign hereditary chorea, Friedreich's ataxia and mitochondrial disease. Acquired causes of chorea include vascular disease, post-infective autoimmune central nervous system disorders (PANDAS), drugs, systemic lupus erythematosus, antiphospholipid syndrome, thyrotoxicosis, AIDS, chorea gravidarum, and polycythaemia rubra vera. The authors suggest an approach to the clinical assessment of chorea, the value of investigations, including genetic tests (for which they offer a structured framework highlighting the importance of prior counselling), and finally briefly discuss symptomatic drug treatment of chorea.
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