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Query: UMLS:C0032463 (polycythemia vera)
 3,374 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The rare presence of the ph1 chromosome in chronic myeloproliferative disorders other than chronic granulocytic leukemia (CGL), i.e. polycythemia vera (PV), myeloid metaplasia with myelofibrosis (MMM) and hemorrhagic thrombocytopenia (HT) raised the question whether or not the Ph1 chromosome is peculiar to CGL. In an attempt to answer this question, the authors reports six cases of positive-Ph1 of which two are from their personal experience and four from the literature. Three of these six cases converted to CGL. The authors conclude that the cases of Ph1-positive PV and HT are transition forms to CGL, and the cases of Ph1-positive MMM are in fact secondary forms derived from CGL.
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PMID:Ph1-positive polycythemia vera. 26 77

The nonleukemic chronic myeloproliferative disorders, polycythemia vera, essential thrombocytosis, and myeloid metaplasia with myelofibrosis, are clonal disorders with similar but distinct clinical and laboratory findings. This review will discuss the diagnostic criteria for each disease, the variable clinical picture, and the therapeutic modalities, actual and theoretical.
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PMID:Clinical aspects of chronic myeloproliferative diseases. 150 10

Diagnosing chronic myeloproliferative disorders (CMPD) can be difficult because of overlap and possible transitions between the different conditions and their similarity to reactive myeloproliferations. DNA analysis was applied to improve differentiation of CMPDs. All subtypes of CMPD analyzed, including chronic myeloid leukemia, agnogenic myeloid metaplasia, polycythemia vera, and essential thrombocythemia, had in common that granulocytes and bone marrow cells were clonal in origin, as shown by X chromosome-linked DNA polymorphism in conjunction with methylation patterns (n = 32). Reactive myeloproliferations, by contrast, showed polyclonal inactivation patterns. Clonality could not distinguish CMPD from cases of myelodysplastic syndrome because the latter (n = 7) also exhibited clonal hematopoiesis. Because of their clonal origin, peripheral granulocytes were used in all cases (n = 201) to detect bcr gene rearrangement. Despite possible morphologic overlap between different types of CMPD, bcr gene rearrangement was specific for chronic myeloid leukemia and could be applied to differentiate chronic myeloid leukemia from other CMPDs in cases of equivocal morphologic diagnosis. Chronic myeloproliferative disorders represent clonal hemopoietic diseases that probably have specific underlying genetic defects. Thus DNA analysis can aid substantially in the differential diagnosis of CMPD.
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PMID:DNA analysis to aid in the diagnosis of chronic myeloproliferative disorders. 161 25

Planimetry of megakaryocytes (MK) was performed in bone marrow biopsies (BMBs) from patients with chronic myeloproliferative disorders (CMPD) to substantiate cytomorphologic differences in this cell lineage between the four main groups of CMPD. The biopsy specimens were classified histologically prior to morphometry, according to the Hannover Classification of CMPD. Five histological groups were investigated, evaluating between 21 and 30 biopsies in each group. The five groups were as follows: (1) Chronic myelocytic leukemia (CML) of common type (CML.CT), (2) CML with megakaryocytic increase (CML.MI), (3) polycythemia vera (P. vera), (4) primary thrombocythemia (PTH), and (5) chronic megakaryocytic-granulocytic myelosis (CMGM). The results of five variables, i.e. the cellular and nuclear size, the cellular and nuclear form factor, and nuclear segmentation, were determined in at least 50 MK per BMB. The results reveal significant differences in MK nuclear and cellular size, as well as in nuclear segmentation between CML and the three other groups in that the nuclear and cellular size of the MK in CML are smaller than in P. vera, PTH, and CMGM. Moreover, the degree of nuclear segmentation or lobulation differs significantly between the three disorders characterized by large MK. Discriminant analysis permits 78-100% reliability of reclassification by morphometry compared with the histologic classification. A reduced reliability of the morphometric classification to around 80% was found between P. vera and PTH, as well as between P. vera and CMGM. In the design of this study, morphometry of MK lends added weight to the subjective classification of these disorders.
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PMID:Planimetric analysis of megakaryocytes in the four main groups of chronic myeloproliferative disorders. 168 18

Studies with G6PD and molecular probes indicate that the myeloid leukemias and the chronic myeloproliferative disorders are clonal diseases. The G6PD data indicate that chronic myelogenous leukemia, polycythemia vera and essential thrombocythemia involve stem cells pluripotent for granulocytes, erythrocytes, megakaryocytes and lymphocytes. Agnogenic myeloid metaplasia is also a clonal disease that involves multipotent hematopoietic stem cells. However, myelofibrosis, the predominant clinical manifestation, occurs secondarily and is not a component of the abnormal clonal proliferation. Acute nonlymphocytic leukemia is a clonal disease, but G6PD studies suggest that there are at least two forms of this leukemia. In one type of ANL, the involved stem cells exhibit pluripotent differentiative expression. In another type of ANL, differentiative expression is largely restricted to the granulocytic pathway. The heterogeneity of ANL has both clinical and pathogenetic implications.
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PMID:Stem cell origin of human myeloid blood cell neoplasms. 170 32

Platelet activation in patients with myeloproliferative disorders is often suggested by increased platelet alpha-granule secretion and an acquired storage pool defect of dense granules. To determine whether activated platelets circulate in patients with chronic myeloproliferative disorders, we evaluated the binding of monoclonal antibodies against activation-dependent epitopes on resting platelets (P 12, CD 63, and CD 62) in 12 patients with prominent megakaryocytic proliferation (8 patients with essential thrombocythemia, 2 with chronic myeloid leukemia, and 2 patients with polycythemia rubra vera). In addition, platelet aggregation in response to collagen, adenosine diphosphate, platelet activating factor, and agglutination with ristocetin was investigated. In 3 patients there was an increased percentage of platelets binding at least 1 activation marker. In 2 other patients, a trend towards increased antibody binding was observed. Binding of the antibody to thrombospondin (P 12) was related to expression of the GMP 140 protein (CD 62, r = 0.76, p = 0.004). There was no correlation of platelet aggregation defects in vitro to increased expression of platelet activation markers or to thrombohaemorrhagic complications. However, circulating activated platelets were detected in three out of five patients with a history of bleeding or thrombotic complications. The results of this preliminary study suggest that some but not all patients with myeloproliferative disorders showed increased amounts of circulating activated platelets. The relation of bleeding and thrombotic complications to the expression of activation-dependent epitopes on platelets in myeloproliferative disorders requires further investigation.
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PMID:Circulating activated platelets in myeloproliferative disorders. 170 9

Thirty-six patients with chronic myeloproliferative disorders (CMPD) were studied as regards blood coagulation and fibrinolysis. These studies revealed various mild abnormalities: activated thromboplastin time (APTT) tended to prolong and the level of factor V decreased significantly. In several cases, the levels of D-dimer, thrombin-antithrombin III complex and plasmin-alpha 2-plasmin inhibitor complex were elevated compared to normal. These results suggest that abnormal coagulation system in the patients with CMPD is related to low grade disseminated intravascular coagulation. Many coagulation factors did not correlate with peripheral blood cell counts. Two patients with polycythemia vera were evaluated for several abnormalities of the coagulation system before and during treatment. Coagulation abnormalities persisted after hematologic control had been achieved. Our results suggest that patients with CMPD have a chronic state of abnormal blood coagulation system even after normalization of blood cell counts.
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PMID:[Abnormal blood coagulation and fibrinolysis in chronic myeloproliferative disorders]. 187 Feb 70

Restriction fragment length polymorphisms of the X-chromosome genes phosphoglycerate kinase and hypoxanthine phosphoribosyl transferase were used to study clonality in peripheral blood leukocytes from 48 women with chronic myeloproliferative disorders (c-MPD). A total of 50% of patients were heterozygous for one or both of the polymorphic loci. These included 17 cases with polycythemia vera, four patients with essential thrombocythemia (ET), and three cases with idiopathic myelofibrosis (IMF). A clear-cut monoclonal X-inactivation pattern was observed in 17 of 24 cases including all IMF patients. Only one patient with PV exhibited a nonclonal composition of her leukocytes, while six cases demonstrated a predominantly clonal pattern in peripheral blood cells. Among the latter category reckoned three of four ET patients. Cell separation analyses were performed in one ET and three PV patients. In all four cases a monoclonal pattern of the granulocyte fraction could be established, while T lymphocytes of these patients were of nonclonal origin. These data suggest that the vast majority of c-MPDs arise from multipotent hematopoietic stem cells. Moreover, this type of clonal analysis might be of help in discriminating between primary MPD and reactive processes.
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PMID:Clonal analysis of chronic myeloproliferative disorders using X-linked DNA polymorphisms. 197 5

In a series of 218 subjects diagnosed as having nonleukemic chronic myeloproliferative disorders in a single institution within a 18-year period, 13 instances of acute transformation were registered. They corresponded to 8 out of 70 patients with idiopathic myelofibrosis (IM), 4 out of 91 with polycythemia vera (PV), and 1 out of 57 with essential thrombocythemia (ET). The actuarial probability of developing such a complication at 100 months from diagnosis reached 20.6% in IM, 8.7% in PV, and 4% in ET. Only 1 IM patient whose condition developed into acute leukemia had received prior cytolytic therapy, whereas, in contrast, all PV and ET patients showing this pattern had previously been treated with either 32P or alkylating agents. On the other hand, acute transformation in IM generally had an insidious presentation, contrasting with its abrupt onset in most PV and ET patients. Most acute leukemias (12 out of 13) exhibited a myeloid phenotype. The patients' median survival from diagnosis of the acute transformation was only 3 months, the development of this complication significantly shortening the patients' overall survival.
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PMID:Acute transformation in nonleukemic chronic myeloproliferative disorders: actuarial probability and main characteristics in a series of 218 patients. 204 44

Twenty-one patients with chronic myeloproliferative disorders, eleven with polycythemia vera (PV) and ten with essential thrombocythemia (ET), were treated with small doses of alpha-2a interferon (IFN). The median follow-up was, respectively, 10.8 months (range 4-22) for PV and 8.11 months (range 4-16) for ET. Six patients with PV and five with ET had been previously treated with conventional cytotoxic drugs, while the remaining patients were newly diagnosed. In four patients with PV we observed a durable normal hematocrit level (PCV less than 0.48) and a reduction of platelet count and spleen size within 4-8 weeks of treatment. Three patients achieved moderate disease control. In the others the disease remained substantially unchanged. Five out of nine evaluable patients with ET showed complete response (CR) within six weeks, one patient had a partial response (PR) and three no response (NR). In one patient with ET the IFN therapy was stopped after twelve days because neurological side effects were observed. All the other patients tolerated long-term treatment very well.
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PMID:Alpha-interferon in polycythemia vera and essential thrombocythemia. 205 65


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