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)

A 20-year-old woman presented with polycythemia vera and was treated with phlebotomy alone for eleven years, following which all clinical manifestations of the disease disappeared. The clinical remission with normal physical findings and normal peripheral blood counts has persisted for a further 11 years. Erythroid colony culture results have paralleled the clinical state. Initial bone marrow cultures revealed spontaneous growth of erythroid burst-forming units (BFU-E). Subsequent cultures of peripheral blood cells throughout most of the period of spontaneous clinical remission have revealed little or no spontaneous growth of BFU-E. This suggests a suppression of the abnormal stem cell clone during the period of remission.
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PMID:Spontaneous remission of polycythemia vera: clinical and cell culture characteristics. 818 76

Polycythaemia vera is a clonal disorder of the haemopoietic stem cell causing a pathologic expansion of the erythroid and sometimes the megakaryocytic and myeloid elements. In order to avoid the possible mutagenic effects of radioactive phosphorus, alkylating agents and hydroxyurea, since 1988 alpha-IFN has been used for the treatment of PV and has been shown to induce and maintain haematological remission. We describe a 24-year-old PV patient with chromosomal abnormalities who achieved not only a reduction of the proliferation of erythroid elements and reticulin content in the bone marrow, but also a complete cytogenetic remission after IFN treatment.
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PMID:Cytogenetic conversion in a case of polycythaemia vera treated with interferon-alpha. 819 36

Patients with polycythaemia and normal controls have been studied to establish and subsequently test non-conventional criteria for the diagnosis of primary polycythaemia (primary proliferative polycythaemia, polycythaemia vera) as compared with conventional Polycythaemia Vera Study Group (PVSG) assessment. One criterion was erythroid colony formation from peripheral blood in a serum-free system, assayed alone and with the addition of recombinant human erythropoietin (Epo), interleukin 3 (IL3), or alpha interferon (alpha-IFN) (Dudley et al. 1990). The remaining criteria were non-culture associated and comprised platelet distribution width (PDW), platelet nucleotide ratio (ATP:ADP), serum erythropoietin and clinical evidence of ischaemic vascular disease. The combination of culture associated and non-culture associated variables, by use of a simple additive scoring system, gave no false positive and only 6% false negative results in distinguishing primary polycythaemia from other polycythaemias and normal controls in those (34 patients Group A) used in its derivation. Testing the scoring system in a newly presenting group (25 patients Group B) was highly satisfactory with no false positives and only a few false negative results (14%). Use of these non-conventional criteria should allow more confident diagnosis of primary polycythaemia, where conventional clinical and laboratory assessment is inconclusive.
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PMID:Primary polycythaemia: diagnosis by non-conventional positive criteria. 824 12

We have investigated the question of erythropoietin (Epo) hypersensitivity versus Epo independence as the basis for the endogenous erythroid bursts (EEBs) that develop in cultures without added Epo from hematopoietic cells of polycythemia vera (PV) patients. Using an improved serum-free (SF) medium containing interleukin (IL)-3, but no insulin-like growth factor-1 (IGF-1), and devoid of contaminants that influence erythropoiesis, we compared circulating normal and PV early erythroid progenitors (BFU-E) with respect to their responses in vitro to recombinant human (rHu) Epo. Cultures were seeded with Ficoll-Hypaque density-separated peripheral blood (PB) mononuclear cells (MNCs), and erythroid bursts, together with their component colonies of > or = 50 cells, were scored in situ at 13 to 16 days of culture. The Epo dose-response curve of BFU-E from PV patients was found to be statistically indistinguishable from that of normal subjects. This observation provides compelling evidence against the Epo-hypersensitivity hypothesis. In the complete SF medium minus Epo, the sensitivity of BFU-E to IGF-1 was much greater in PV than in normals, the dose-response curve being shifted to the left by at least 2 orders of magnitude. These data show that the erythroid progenitor cell response in PV is hypersensitive to IGF-1, and independent of Epo. The data also emphasize the importance of truly SF medium conditions for assessment of progenitor cell sensitivities to recombinant growth factors. Depletion of adherent cells totally prevented erythroid burst formation by normal circulating progenitors, but did not prevent the hypersensitive response to IGF-1 of such cells from PV patients. Hence, again unlike its normal counterpart, the progenitor cell response in PV appears to be independent of adherent cell control.
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PMID:Circulating erythroid progenitors in polycythemia vera are hypersensitive to insulin-like growth factor-1 in vitro: studies in an improved serum-free medium. 827 28

We used the methylcellulose-culture technique to determine the utility of the erythroid progenitor growth in vitro from nonadherent T-depleted bone marrow and peripheral blood cells in distinguishing polycythemia vera (PV) from essential thrombocythemia. Thirty patients with PV (group A) and 30 patients who presented with idiopathic marked thrombocytosis with platelet count greater than 1,000 x 10(9)/L and a normal or reduced hemoglobin (Hb) level (group B) were studied at initial presentation. Endogenous (erythropoietin-independent) erythroid colonies (EEC) were found in all patients in group A and 13 in group B. The numbers of EEC were comparable between patients in group A and the 13 patients with EEC in group B, 11 of whom with initial Hb levels ranging between 6.4 g/dL and 12.6 g/dL were found to have PV 2 to 45 months after initial evaluation. The number of EEC did not correlate with the time to the progression of polycythemia, whereas myelosuppression delayed the subsequent development of PV. Of the two patients with EEC in group B who did not develop PV, both received chemotherapy soon after presentation, which might preclude the evidence of polycythemia evolution. None of the other patients in group B who did not form EEC developed PV with a median follow-up of 24 months. This study indicates that the assessment of EEC in bone marrow or blood is helpful in early identification of PV or prediction of polycythemia evolution in patients with marked thrombocytosis in whom polycythemia has been initially masked or anemia is present.
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PMID:Identification of masked polycythemia vera from patients with idiopathic marked thrombocytosis by endogenous erythroid colony assay. 829 36

Five patients with erythrocytosis associated with renal failure on maintenance hemodialysis were investigated for in vitro erythroid progenitor growth and the effect of their uremic sera on normal erythropoiesis. The duration of hemodialysis prior to discovery of erythrocytosis ranged from 1 week to 96 months. None had acquired cystic disease and no other known cause of increased erythropoietin (Epo) production was identified. With the presence of Epo in cultures, all five patients grew erythroid colonies within normal or higher than normal ranges. Three patients formed spontaneous erythroid colonies in the absence of added Epo; all three fulfilled the clinical diagnosis of polycythemia vera (PV). The uremic sera from patients with PV lacked either a stimulating or an inhibiting effect on normal erythropoiesis. The association between renal failure and PV was coincidental. The other two patients without endogenous erythroid colony formation had enhanced erythropoietic activity in their sera, which increasingly stimulated the erythroid colony growth by normal bone marrow cells as the concentration of the uremic serum was increased. The etiology of increased Epo production in these 2 patients remained undefined during long-term follow-up. The present study on five uremic patients with polycythemia showed two different underlying mechanisms of erythrocytosis--characteristic autonomous erythroid proliferation for PV in three patients and inappropriate idiopathic Epo production in two patients.
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PMID:Erythrocytosis in patients with renal failure on hemodialysis: study of underlying mechanism by in vitro erythroid culture assay. 833 Jun 48

Erythropoietin (EPO) is a prime stimulating factor for red cell production. EPO is a glycoprotein which has a molecular weight of 34,000, and is mainly produced by the kidney. EPO stimulates the differentiation and proliferation of erythroid progenitor cells in the bone marrow. The rate of production of EPO is regulated primarily by renal oxygen availability. Because anemia reduces renal oxygen availability, anemic stress accelerates EPO production in the kidney. Recently, EPO has mainly been determined by radioimmunoassay. Serum EPO titer is usually inversely correlated with hemoglobin concentration, as typically shown in iron deficiency anemia. Serum EPO titers in aplastic anemia are much higher than those in iron deficiency anemia relative to the hemoglobin concentration. Serum EPO titers in anemia caused by malignancies sometimes differ considerably among patients. Serum EPO in renal anemia usually show low titers irrespective of the degree of anemia. Serum EPO titers in untreated polycythemia vera are lower than those in treated polycythemia vera or secondary polycythemia. Determination of serum EPO is useful in differential diagnosis of polycythemia vera. Recombinant human EPO has been used to treat various anemias including renal anemia, refractory anemia, anemia in malignancies and secondary anemia. Determination of serum EPO titers is also valuable in many other situations of clinical medicine.
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PMID:[Erythropoietin determination in clinical medicine]. 835 Apr 98

A 74-year-old male patient was seen on December 15, 1980 because of right shoulder pain and leukocytosis. The spleen and the liver were enlarged, and palpable, 3 and 4 fingerbreadths below the costal margin respectively. The red blood cell count (RBC) was 899 x 10(4)/microliters, hemoglobin (Hb) 20.6 g/dl, reticlocyte (Ret) 7/1000, platelets (Plt) 34.2 x 10(4)/microliters, the white blood cell count (WBC) 26,800/microliters with 86% neutrophils. A bone marrow aspiration showed the nucleated cell count (NCC) to be 16.5 x 10(4)/microliters, and the myeloid/erythroid ratio (M/E) 2.0. The patient was treated with venesection and later with carboquone. Since September 1990 he has not been treated with any agents because of erythrocytopenia. In July 25, 1991, the spleen was enlarged, and palpated 8 fingerbreadths below the costal margin. The RBC was 456 x 10(4)/microliters, Hb 12.5 g/dl, Ret 9/1000, Plt24.2 x 10(4)/microliters, the WBC41,500/microliters with 90% neutrophils. Bone marrow aspiration showed the NCC to be 16.5 x 10(4)/microliters, M/E14.3, with no atypical cells. Chromosome studies of marrow cells revealed no Ph1 chromosome. Many hematologic malignancies have been occasionally associated with polycythemia vera (PV), but chronic neutrophilic leukemia associated with PV is a very rare condition.
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PMID:[A case of chronic neutrophilic leukemia associated with polycythemia vera]. 836 77

T cells and monocytes from patients with polycythemia vera (PV) were isolated and grown in culture. The conditioned medium was tested for the presence of soluble factors that promote proliferation of erythroid colonies from the blood of healthy donors. We show that T cells from all 14 PV patients that were examined secrete factor/s that stimulate the proliferation of erythroid burst-forming units (BFU-E) in the absence of an external source of erythropoietin and BPA. Addition of cyclosporin A to the culture did not inhibit the production of this activity. The conditioned medium from monocytes of PV patients can also stimulate normal BFU-E but to a much lesser extent than T-cell conditioned medium. Such stimulation was not observed with control T cells or monocytes. We observed that the fraction of DR-positive T cells was significantly higher in PV patients comparing to normal. These results suggest that PV patients possess an abnormally high level of circulating activated T cells which may in turn be the source of the putative factor that facilitates uncontrolled erythroid differentiation.
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PMID:Soluble factors from peripheral blood T-cells of patients with polycythemia vera stimulate normal BFU-E. 837 88

Polycythemia vera (PV) was diagnosed in a four-year-old domestic shorthair evaluated for hind-limb ataxia, extension of all claws, and difficulty in jumping to elevated surfaces. Mild cardiac hypertrophy also was diagnosed. Initial laboratory evaluation revealed polycythemia (packed cell volume [PCV], 75%) and normal serum total protein (7.5 g/dl). Definitive diagnosis of PV was reached by excluding causes of relative and secondary absolute polycythemia using radiography, ultrasonography, and blood gases, and by measuring serum erythropoietin concentration by radioimmunoassay (13 mU/ml) and an enzyme-linked immunosorbent assay (ELISA) method (8.0 mU/ml). Bone-marrow biopsy revealed relative erythroid hyperplasia characteristic of myeloproliferative disease. Clinical signs were controlled with hydroxyurea (12.2 mg/kg body weight) and occasional phlebotomy. Polycythemia vera is an uncommon feline disease, and clinical reports on the use of hydroxyurea to manage the condition in the cat are lacking.
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PMID:Polycythemia vera in a cat and management with hydroxyurea. 854 63


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