Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038002 (splenomegaly)
 9,873 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A JAK2(V617F) mutation is frequently found in several BCR/ABL-negative myeloproliferative disorders. To address the contribution of this mutant to the pathogenesis of these different myeloproliferative disorders, we used an adoptive transfer of marrow cells transduced with a retrovirus expressing JAK2(V617F) in recipient irradiated mice. Hosts were analyzed during the 6 months after transplantation. For a period of 3 months, mice developed polycythemia, macrocytosis and usually peripheral blood granulocytosis. Transient thrombocytosis was only observed in a low-expresser group. All mice displayed trilineage hyperplasia in marrow and spleen along with an amplification of myeloid and erythroid progenitor cells and a formation of endogenous erythroid colonies. After 3 to 4 months, polycythemia regressed, abnormally shaped red blood cells and platelets were seen in circulation, and a deposition of reticulin fibers was observed in marrow and spleen. Development of fibrosis was associated with anemia, thrombocytopenia, high neutrophilia, and massive splenomegaly. These features mimic human polycythemia vera and its evolution toward myelofibrosis. This work demonstrates that JAK2(V617F) is sufficient for polycythemia and fibrosis development and offers an in vivo model to assess novel therapeutic approaches for JAK2(V617F)-positive pathologies. Questions remain regarding the exact contribution of JAK2(V617F) in other myeloproliferative disorders.
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PMID:JAK2V617F expression in murine hematopoietic cells leads to MPD mimicking human PV with secondary myelofibrosis. 1667 Feb 66

Myelofibrosis with myeloid metaplasia (MMM) is a clinicopathologic entity characterized by stem cell-derived clonal myeloproliferation, ineffective erythropoiesis, extramedullary hematopoiesis, and bone marrow fibrosis and osteosclerosis. Patients with MMM have shortened survival and their quality of life is compromised by progressive anemia, marked hepatosplenomegaly, and severe constitutional symptoms including cachexia. After decades of frustration with ineffective therapy, patients are now being served by promising treatment approaches that include allogeneic hematopoietic stem cell transplantation and immunomodulatory drugs. Recent information regarding disease pathogenesis, including a contribution to the myeloproliferative disorder phenotype by a gain-of-function JAK2 mutation (JAK2(V617F)), has revived the prospect of targeted therapeutics as well as molecular monitoring of treatment response. Such progress calls for standardization of response criteria to accurately assess the value of new treatment modalities, to allow accurate comparison between studies, and to ensure that the definition of response reflects meaningful health outcome. Accordingly, an international panel of experts recently convened and delineated 3 response categories: complete remission (CR), partial remission (PR), and clinical improvement (CI). Bone marrow histologic and hematologic remissions characterize CR and CR/PR, respectively. The panel agreed that the CI response category is applicable only to patients with moderate to severe cytopenia or splenomegaly.
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PMID:International Working Group (IWG) consensus criteria for treatment response in myelofibrosis with myeloid metaplasia, for the IWG for Myelofibrosis Research and Treatment (IWG-MRT). 1667 7

Among 460 consecutive patients with essential thrombocythemia (ET) seen at our institution, 19 cases (4%) of abdominal vein thrombosis (AVT) were documented either at (n = 9) or after (n = 10) diagnosis. Women (P = 0.03) and the young (P = 0.002) were preferentially affected. Accordingly, clinical comparisons were performed among three groups of female patients: those with AVT (group A; n = 17), a control group without AVT but closely matched to group A in terms of age and year of diagnosis (group B; n = 34), and all female patients without AVT (group C; n = 288). As expected from the consequences of AVT-associated portal hypertension and anticoagulant therapy, patients in group A experienced significantly higher rates of hemorrhage, palpable splenomegaly, and anemia. Unexpectedly, however, compared with group B, group A displayed both a higher conversion rate into myelofibrosis/acute leukemia (P = 0.0008) and a shorter median survival (116 vs. 156 months; P = 0.0012). Multivariable analysis including all female patients with ET identified AVT, along with advanced age, leukocytosis, and tobacco use, as an independent risk factor for inferior survival. Groups A, B, and C did not differ in either JAK2(V617F) mutational frequency or incidence of non-abdominal thrombosis. We conclude that AVT in ET is a marker of aggressive disease biology.
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PMID:Abdominal vein thrombosis in essential thrombocythemia: prevalence, clinical correlates, and prognostic implications. 1685 28

The clinical criteria for the diagnosis of essential thrombocythemia (ET) according to the polycythemia vera study group (PVSG) do not distinguish between ET and thrombocythemia associated with early stage PV and prefibrotic chronic idiopathic myelofibrosis (CIMF). The clinical criteria of the PVSG for the diagnosis of polycythemia vera (PV) only detects advanced stage of PV with increased red cell mass. The bone marrow criteria of the World Health Organization (WHO) are defined by pathologists to explicitly define the pathological criteria for the diagnostic differentiation of ET, PV, and prefibrotic and fibrotic CIMF. As the clinical PVSG and the pathological WHO criteria show significant shortcomings, an updated set of European Clinical and Pathological (ECP) criteria combined with currently available biological and molecular markers are proposed to much better distinct true ET from early PV mimicking ET, to distinguish ET from thrombocythemia associated with prefibrotic CIMF, and to define the various clinical and pathological stages of PV and CIMF that has important therapeutic and prognostic implications. Comparing the finding of clustered giant abnormal megakaryocytes in a representative bone marrow as a diagnostic clue to MPD, the sensitivity for the diagnosis of MPD associated with splanchnic vein thrombosis was 63% for increased red cell mass, 52% for low serum EPO level, 72% for EEC, and 74% for splenomegaly indicating the superiority of bone marrow histopathology to detect masked early and overt MPD in this setting. The majority of PV and about half of the ET patients have spontaneous EEC, low serum EPO levels and PRV-1 over-expression and are JAK2 V617F positive. The positive predictive value for the diagnosis of PV of spontaneous growth of endogenous erythroid colonies (EEC) of peripheral blood (PB) and bone marrow (BM) cells is about 80-85% when either PB or BM EEC assays, and up to 94% when BM and PB EEC assays were performed. The diagnostic impact of low serum EPO levels (ELISA assay) in a large study of 186 patients below the normal range (<3.3 IU/l) had a sensitivity specificity and positive predictive value of 87%, 97% and 97.8%, respectively, for the diagnosis of PV. There is a significant overlap of serum EPO levels in PV versus control and controls versus SE. The specificity of a JAK2 V617F PCR test for the diagnosis of MPD is high (near 100%), but only half of ET and MF (50%) and the majority of PV (up to 97%) are JAK2 V617F positive. The use of biological markers including JAK2 V617 PCR test, serum EPO, PRV-1, EEC, leukocyte alkaline phosphatase score and peripheral blood parameters combined with bone marrow histopathology has a high sensitivity and specificity (almost 100%) to diagnose the early and overt stages of ET, PV and CIMF in JAK2 V617F positive and negative MPDs.
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PMID:Current diagnostic criteria for the chronic myeloproliferative disorders (MPD) essential thrombocythemia (ET), polycythemia vera (PV) and chronic idiopathic myelofibrosis (CIMF). 1691 93

Recently, the acquired mutation JAK2-V617F has been described in the majority of patients with myeloproliferative disorders (MPDs). In this study we evaluated its clinical and laboratory correlates in 166 patients with MPDs. The mutation was detected by allele-specific PCR in 119 patients: 81.4% (35/43) of those with polycythemia vera, 69.1% (77/111) of those with essential thrombocythemia and 58.1% (7/12) of those with idiopathic myelofibrosis. The patients carrying the mutation were older (p=0.02) and displayed higher levels of Ht (p<0.01) and Hb (<0.01) and lower erythropoietin levels (p<0.01). Moreover, mutation-positive patients displayed a higher probability of having leucocytosis, splenomegaly and thrombotic events (three-fold, two-fold and two-fold, respectively) than mutation-negative patients. These correlations imply that the JAK2-V617F mutation may be useful for the classification and the management of patients with MPDs.
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PMID:Correlations of JAK2-V617F mutation with clinical and laboratory findings in patients with myeloproliferative disorders. 1704 48

The Philadelphia chromosome (Ph)-negative myeloproliferative disorders (MPDs) include essential thrombocythemia (ET), idiopathic myelofibrosis (IMF), and polycythemia vera (PV). All of these disorders are clonal hematologic malignancies originating at the level of the pluripotent hematopoietic stem cell. Recently, activating mutations of the intracellular cytokine-signaling molecule JAK2 have been identified in > 90% of patients with PV and in 50% of those with IMF and ET. In addition, a mutation of the thrombopoietin receptor, MPLW515L, has been documented in some patients with IMF. Both mutations activate JAK-STAT signaling pathways and likely play a role in disease progression. Both ET and PV are associated with prolonged clinical courses associated with frequent thrombotic and hemorrhagic events, and progression to myelofibrosis and acute leukemia. IMF has a much poorer prognosis and is associated with cytopenias, splenomegaly, extramedullary hematopoiesis, and bone marrow fibrosis. Stratification of risk for the development of complications from Ph-negative MPDs has guided the identification of appropriate therapies for this population. Intermediate/high-risk IMF or myelofibrosis after ET or PV is associated with a sufficiently poor prognosis to justify the use of allogeneic stem cell transplantation, which is capable of curing such patients. Reduced-intensity conditioning in preparation for allogeneic stem cell transplantation has permitted older patients with IMF to undergo transplantation with increasing success.
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PMID:Philadelphia chromosome-negative myeloproliferative disorders: biology and treatment. 1722 72

Chronic neutrophilic leukaemia is a rare myeloproliferative disease characterised by splenomegaly, sustained neutrophilia, raised vitamin B12 level and absence of the Philadelphia chromosome. We report a 74-year-old man who presented first with Sweet's syndrome and subsequently leukocytosis. He had splenomegaly, a raised vitamin B12 level, serum uric acid and neutrophil alkaline phosphatase score. Cytogenetic study of the marrow was normal and peripheral blood for BCR-ABL gene transcript was not detectable. He subsequently passed away with bronchopneumonia.
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PMID:Chronic neutrophilic leukaemia. 1734 75

The Val617Phe point mutation of Janus kinase 2 gene is believed to participate in the pathogenesis of myeloproliferative syndrome characterised by the clonal alteration of hematopoietic stem cells. According to current results, the frequency of Val617Phe activating mutation is around 80% in polycythaemia vera, 35% in essential thrombocythemia, and 50% in chronic idiopathic myelofibrosis. The diagnoses of polycythemia vera, essential thrombocythemia and idiopathic myelofibrosis were so far based on the exclusion of secondary factors as well as bone marrow biopsy histology. The goal of the present work was to establish simple molecular genetic techniques for the routine testing of Janus kinase 2 gene Val617Phe mutation, and to compare the clinical phenotypes of Val617Phe mutation positive and negative myeloproliferative syndromes. We employed the allele specific polymerase chain technique for detection of Val617Phe mutation in 252 patients with myeloproliferative syndrome. We measured Val617Phe frequency as 85,4% (117/137) in polycythemia vera, 56,6% (56/99) in essential thrombocythemia, and 87,5% (14/16) in idiopathic myelofibrosis. We found significantly elevated hemoglobin levels and white blood cell counts (measured at the time of diagnosis) in Val617Phe-positive polycythemia vera and essential thrombocythemia patient groups compared to Val617Phe-negative patients. However, the frequencies of splenomegaly and other complications (thrombosis, bleeding, transformation to acute leukemia) were not significantly different between the mutation-positive and negative groups. In conclusion, the non-invasive mutation analysis of the Janus kinase 2 Val617Phe is suitable for routine laboratory application and helps the differential diagnosis of myeloproliferative syndrome. Although the exact role of Val617Phe mutation testing has not yet been identified on the basis of a broad professional consensus, the testing is suggested in cases of erythrocytoses and thrombocytoses of unknown origin.
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PMID:[Role of the activating mutation Val617Phe of Janus kinase 2 gene in myeloproliferative diseases and significance of its detection]. 1734 40

We performed a multi-institutional retrospective analysis of the morphologic features, immunophenotype, cytogenetics, and BCR-ABL transcript characterization of cases of Philadelphia chromosome-positive acute myeloid leukemia (Ph+ AML). We compared these cases with cases of documented chronic myelogenous leukemia in myeloid blast crisis (CML-MBC). Patients with Ph+ AML were less likely to have splenomegaly or peripheral basophilia and had lower bone marrow cellularity and myeloid/erythroid ratios than patients with CML-MBC. Additional specific cytogenetic abnormalities that typically occur in CML-MBC were less common in Ph+ AML. Of 7 patients with Ph+ AML treated with imatinib mesylate, 6 showed at least a partial hematologic response, but the responses were of a short duration (median, 2.5 months). The median survival of patients with Ph+ AML was 9 months, similar to that of patients with CML-MBC (7 months). Ph+ AML is a rare aggressive acute leukemia with some features distinct from CML-MBC.
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PMID:Philadelphia chromosome-positive acute myeloid leukemia: a rare aggressive leukemia with clinicopathologic features distinct from chronic myeloid leukemia in myeloid blast crisis. 1736 42

An outpatient HIV clinic was opened in March 2005 in Binh Thanh District, a poor section of Ho Chi Minh City, Vietnam. Over 1500 patients were seen in the first year. The average age of patients was 27 years. Men represented 77% of the clinic population, women, 23% and children under the age of 16 years of age, 5% of the population. The most common risk factor among men was being an injecting drug user (IDU), 76%, and among women, being married to an IDU HIV-positive man, 35%. Physical signs of disease were uncommon: lymphadenopathy in 24% and hepatomegaly and splenomegaly in 4% and 3%, respectively. Men and women were anaemic at presentation, with a mean haemoglobin of 11.9 g/dL and 11.1 g/dL, respectively. An overwhelming majority of patients had profound immunodeficiency. The mean CD4+ cell count was 164 cells/mL and the median was 69 cells/mL. No correlation was found between the World Health Organization's stage of disease and the CD4+ cell count. Thus, the former is a poor predictor of immunity in this population. Data regarding opportunistic infections diagnosed at the first visit were studied. Candidiasis of the oral pharynx, oesophagus or vagina was found in 34.5% of the patients, and pulmonary and extrapulmonary tuberculosis was found in 32% of the patients. Pneumocystis carinii pneumonia (PCP) was diagnosed in only 3% of the patients. Cotrimoxazole prophylaxis is advocated for HIV-infected Vietnamese, but the incidence of PCP is negligible and resources could be spent elsewhere. The various opportunistic infections seen in this resource-poor clinic setting is likely to be a pattern of presentation of HIV-infected Vietnamese for some time to come.
Int J STD AIDS 2007 Jul
PMID:Clinical features of HIV/AIDS patients presenting to an inner city clinic in Ho Chi Minh City, Vietnam. 1762 7


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