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

Diagnosis of chronic myeloproliferative disorders (CMPD) can encounter difficulties due to overlaps and possible transitions between the different entities and their similarity to reactive myeloproliferations. In this study DNA analysis has been applied to improve differentiation of CMPD. All subtypes of CMPD analyzed, including chronic myeloid leukemia (CML), agnogenic myeloid metaplasia (AMM), polycythemia vera (PV), and essential thrombocythemia (ET), 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. Reactive myeloproliferations, by contrast, revealed a polyclonal inactivation pattern. Clonality could not distinguish CMPD from cases of myelodysplastic syndrome (MDS) since the latter also exhibited clonal hematopoiesis. AMM belongs to the group of myeloproliferative syndromes. Up to now the cellular phase at onset of the disease (megakaryocytic myelosis) has not been analyzed for clonality of the hematopoietic cells. Granulocytes as well as bone marrow cells from the cellular phase and advanced stages of the disease revealed a monoclonal inactivation pattern of X-chromosomal genes. These results show that the cellular phase already represents a monoclonal, and hence probably a neoplastic, proliferation of a pluripotent stem cell. The monoclonality of granulocytes could also be demonstrated in patients with splenomegaly and strongly argues against a compensatory proliferation of regular hematopoiesis in this organ. Because of their clonal origin, peripheral granulocytes were used in all cases (n = 244) for the detection of bcr-gene rearrangement. Despite possible morphological overlaps between different types of CMPD, bcr-gene rearrangement proved to be specific for CML and could be applied to differentiate CML from other CMPD in cases of uncertain morphological diagnosis. It is concluded that CMPD represent clonal hemopoietic disorders that probably have specific underlying genetic defects. Thus, DNA analysis can substantially aid in the differential diagnosis of CMPD.
 ...
PMID:[Histopathology and molecular pathology of chronic myeloproliferative disorders]. 837 86

The chronic myeloproliferative disorders (MPD) comprise polycythemia vera (PV), idiopathic thrombocythemia (IT), chronic myeloid leukemia (CML) and myelofibrosis/osteomyelosclerosis (MF/OMS). Bone marrow biopsies of 3500 patients with known or suspected MPD were studied, and the clinical and morphologic variables registered were utilized for multivariate data analysis by selected BMD computer programs. The histologic criteria and the histologic subdivisions, as well as the evolution and prognosis of disease are outlined for each of the clinical entities. The results show that a bone marrow biopsy provides independent diagnostic and prognostic data in this group of hematologic malignancies and therefore constitutes an additional parameter in the diagnostic investigation of patients with suspected or established MPD.
 ...
PMID:Potential of bone marrow biopsy in chronic myeloproliferative disorders (MPD). 843 14

Chromosomal deletions of band 13q14 occur recurrently in BCR/ABL negative chronic myeloproliferative disorders (CMPD), including myelosclerosis with myeloid metaplasia (MMM), polycythemia vera (PV), essential thrombocythemia (ET), juvenile chronic myeloid leukemia (JCML), and the so-called BCR/ABL- chronic myeloid leukemia (CML). The RBI tumor suppressor locus, mapping to 13q14, has long since been hypothesized as the important gene. In this report, we have determined the frequency of 13q14 deletions at the molecular level in a large panel of BCR/ABL- CMPD at different disease stages and performed a detailed genetic analysis of gross rearrangements/deletions and point mutations of the RBI gene in these disorders. Our data show that molecular deletions of 13q14 are detected in a relatively large fraction of BCR/ABL- CMPD (38%), that they appear to be more frequent in MMM than in other BCR/ABL- CMPD, and that they may be present at diagnosis or occur during blastic evolution of the neoplasia. The RBI gene displayed a germline configuration in all BCR/ABL- CMPD tested, suggesting that 13q14 deletions in these disorders affect a tumor suppressor locus distinct from RBI.
 ...
PMID:Genetic analysis of chromosome 13 deletions in BCR/ABL negative chronic myeloproliferative disorders. 852 91

Patients with polycythemia vera (PV) or essential thrombocythemia (ET) show a high frequency of thrombosis. The reduction of hematocrit after phlebotomy and normalization of platelet counts do not completely eliminate thrombotic risk. Some preliminary studies reported a reduction in the concentration of natural anticoagulants (NA) in this group of patients. For this reason we evaluated protein S (PS) total antigen, antithrombin III (AT III), and protein C (PC) activity in 81 patients with chronic myeloproliferative disorders (33 with PV and 48 with ET). Data were compared with those obtained in 70 healthy sex- and age-matched subjects. Fifty-seven percent of patients (46 out of 81) showed one or more thrombotic episodes at diagnosis or during follow-up. Interestingly, we found a NA deficit in 43.5% of patients with thrombosis versus only 5.7% in the group of patients without thrombosis. These results may suggest new interpretations about the pathogenesis of thrombosis in PV or ET patients.
 ...
PMID:Reduction of antithrombin III, protein C, and protein S levels and activated protein C resistance in polycythemia vera and essential thrombocythemia patients with thrombosis. 863 6

Polycythemia vera shares basic features of pathogenesis with other subtypes of the group of chronic myeloproliferative disorders. All myelopoietic cells are derived from one transformed hemopoietic stem cell. Genetic instability of mitotic clonal cells explains the risk of leukemic transformation, which may be enhanced by cytoreductive treatment. Recent data show that erythroid hyperplasia is not due to erythropoietin hypersensitivity, but rather to abnormal stimulation by other cytokine growth factors. Treatment as established by clinical trials has almost normalized life expectancy in older patients, but the optimal strategy for subgroups of patients is still unknown. For younger patients, new and potentially curative approaches should be investigated.
 ...
PMID:The present state of pathophysiology and therapeutic trials in polycythemia vera. 892 77

The neutrophil superoxide (O2-)-producing capacity in 57 patients with chronic myeloproliferative disorders (MPDs) and eight patients with chronic myelomonocytic leukemia (CMML) was investigated. O2- release in neutrophils stimulated by chemotactic peptide was markedly increased in all types of chronic MPD, including chronic myelogenous leukemia in both chronic phase and blastic crisis, polycythemia vera, and essential thrombocythemia, but was normal in CMML, which is thought to be a myelodysplastic disorder rather than MPD. Increase in O2(-)-producing capacity in MPD was also observed when other receptor-mediated agonists such as interleukin-8 and concanavalin A were used, but not when phorbol ester, a direct activator of protein kinase C, was used as the triggering agonist of O2- release. Priming effects of granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage CSF (GM-CSF), and tumor necrosis factor (TNF) on chemotactic peptide-induced O2- release was observed in all patients with MPD and CMML, though fold enhancement of priming effects was much less in MPD compared with normal subjects. In addition, the priming effects of TNF were less than those of GM-CSF in 10 cases, whereas the priming effects of TNF were consistently and markedly greater than those of GM-CSF in normal subjects. Tyrosine phosphorylation of 42-kDa protein stimulated by G-CSF, GM-CSF, and TNF was observed in CML neutrophils to be identical to that in normal neutrophils. Present results indicate specific potentiation of the receptor-mediated route of signaling that is linked to the respiratory burst and downregulated responsiveness to cytokines in neutrophils in patients with all types of chronic MPD, suggesting in vivo priming of patient neutrophils via certain mechanism by cytokines or related stimuli in these hematological disorders.
 ...
PMID:Increased neutrophil respiratory burst in myeloproliferative disorders: selective enhancement of superoxide release triggered by receptor-mediated agonists and low responsiveness to in vitro cytokine stimulation. 898 3

The chronic myeloproliferative disorders (CMPD) are considered the main etiology of Budd-Chiari syndrome in Western countries. Moreover, an occult CMPD has been recently identified in most patients with idiopathic hepatic vein thrombosis. In order to determine the frequency of the association between the above entities and to analyze the clinical and hematologic features of such patients, fourteen cases of Budd-Chiari syndrome diagnosed at a single institution over a five year period were reviewed. In 6 patients a CMPD was identified, with this being the first cause of the syndrome. Median age of the later six patients was 32 years (range: 14-54), and 4 were females. In all cases the CMPD was suspected due to the presence of hematological abnormalities, including a high hematocrit (5 cases), leucocytosis (4 cases) and thrombocytosis (3 cases). Five patients had polycythemia vera (PV) and one idiopathic myelofibrosis. In an additional Budd-Chiari patient with polycythemia, PV was ruled out on the basis of high serum erythropoietin and the absence of endogenous growth of erythroid colonies in the hematopoietic progenitor culture. The CMPD treatment included phlebotomies and hydroxiurea, whereas the Budd-Chiari syndrome was treated in most patients with transjugular intrahepatic portosystemic stent-shunt. One patient died from a gastrointestinal hemorrhage at 48 months from Budd-Chiari diagnosis, and the remaining five are alive after a median follow-up of 28 months.
 ...
PMID:[Budd-Chiari syndrome associated with chronic myeloproliferative syndromes: analysis of 6 cases]. 906 8

Serum soluble interleukin-2 receptor (sIL-2R) levels were determined in patients with chronic myeloproliferative disorders (CMPD): 18 with chronic myelogenous leukemia in chronic phase (CML in CP), seven with CML in accelerated phase (AP) or blastic crisis (BC), six with polycythemia vera (PV), eight with essential thrombocythemia (ET), one with primary myelofibrosis (PMF), and 50 controls. The mean (+/-S.E.M.) levels were higher in CMPD than in controls (CML in AP or BC, 2693 +/- 694 U/ml, P < 0.0001; CML in CP, 792 +/- 63 U/ml, P < 0.0001; PV 553 +/- 89 U/ml, P < 0.05; ET, 449 +/- 56 U/ml; PMF, 628 U/ml vs. controls, 395 +/- 25 U/ml). Patients with CML in CP had significantly higher serum sIL-2R levels than patients with ET (P < 0.005), and levels were markedly elevated in AP and BC (P < 0.001). Serum sIL-2R levels were positively correlated with WBC count and lactic dehydrogenase in CMPD, and in CML in CP. Serum sIL-2R levels in CMPD were negatively correlated with RBC and platelet counts. Serum sIL-2R levels were significantly lower in patients with CML in CP who showed a cytogenetic response after interferon (IFN) therapy than in those who showed no response (P < 0.05). These findings suggest that a high serum sIL-2R level reflects the leukocyte growth in CMPD and is useful both for differentiating CML from other CMPD and for predicting the response to IFN therapy in CML.
 ...
PMID:Clinical significance of serum soluble interleukin-2 receptor in chronic myeloproliferative disorders. 907 16

Using flow cytometry, we quantitatively examined the density of the CD16 (IgG Fc receptor III) antigen on neutrophils in healthy control subjects, in patients with neutrophilia due to bacterial infection, and in patients with chronic myeloproliferative disorders (chronic myeloid leukemia [CML], polycythemia vera, or essential thrombocythemia). The density was expressed as the mean fluorescence intensity of neutrophils stained with fluorescein isothiocyanate-labeled anti-CD16 monoclonal antibody. We also determined leukocyte alkaline phosphatase activity semiquantitatively in the same population. The mean (+/- SD) density of the CD16 antigen on neutrophils in patients with CML (n = 13; 240.4 +/- 134.8) was lower (P<.001 ) than in healthy control subjects (n = 25; 656.6 +/- 238.0), and the density was also lower than in patients with bacterial infection (n = 15; 671.5 +/- 288.1), polycythemia vera (n = 7; 552.6 +/- 99.9), or essential thrombocythemia (n = 11; 671.5 +/- 411.5). The density of the CD16 antigen was 300 or more in all healthy control subjects and in all patients examined, except for those with CML. The CD16 antigen density was less than 300 in 10 of the 13 patients with CML. Leukocyte alkaline phosphatase activity was also low in 10 of the 13 patients with CML. These findings indicate that flow cytometric analysis of the density of neutrophil CD16 antigen is useful for the differential diagnosis of CML from other chronic myeloproliferative disorders.
 ...
PMID:CD16 antigen density on neutrophils in chronic myeloproliferative disorders. 953 1

Among the chronic myeloproliferative disorders, polycythemia vera and essential thrombocythemia are unique because of their association with thrombohemorrhagic manifestations and their relatively indolent clinical course. Patients with essential thrombocythemia may not have a significant shortening of life-expectancy and most may not require specific therapy. However, patients with polycythemia vera have a significant risk of transformation of polycythemia vera into acute leukemia or postpolycythemic myelofibrosis (or both). 'High-risk-for-thrombosis' patients with either polycythemia vera or essential thrombocythemia require specific therapy with a platelet-lowering agent to prevent thrombotic complications. Currently, the standard agent used for this is hydroxyurea. However, its tetratogenic and leukemogenic potential has been of concern. As a result, new platelet-lowering agents are being evaluated in the treatment of polycythemia vera and essential thrombocythemia. Anagrelide and interferon alfa are two such agents and have been shown to be effective in reducing platelet counts in patients with chronic myeloproliferative disorders. The putative mechanism of action of these drugs, their specific activity in polycythemia vera and essential thrombocythemia, side-effect profile, and current indications are discussed herein.
 ...
PMID:New drugs in essential thrombocythemia and polycythemia vera. 921 1


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>