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)

Recent studies have generated data demonstrating significant clinical activity of alpha-interferon therapy in each of six hematological malignancies, chronic myeloid leukaemia, essential thrombocythemia, polycythemia rubra vera, non-Hodgkin's lymphomas, multiple myelomatosis and hairy cell leukaemia.
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PMID:alpha-Interferon in hematological malignancies. 136 59

Clinical trials have shown that interferon (IFN) have myelosuppressive effects that can help reduce the uncontrolled clonal growth of hematopoietic cells in myeloproliferative disease. There are at least four diseases that are considered to be myeloproliferative disorders: chronic myelogenous leukemia, myelofibrosis polycythemia vera and idiopathic thrombocythemia. Recombinant IFN alpha has shown promise in inducing haematological and cytogenetic remission in some patients with chronic myelogenous leukemia. The exact role of IFN in prolonging the life of CML patients, however, remains to be determined in larger studies of longer duration. Preliminary evidence suggests that in myelofibrosis it may be more efficacious in the cellular than in fibrotic or osteosclerotic phase. IFN alpha has been reported to be of value in controlling excess platelet production in chronic myelogenous leukemia and idiopathic thrombocythemia as well as in reducing of red cell mas in polycythemia vera.
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PMID:[Use of interferon in the treatment of chronic myeloproliferative disorders]. 148 70

Recombinant interferon alfa-2a has been shown to be an effective induction agent in essential thrombocythaemia and thrombocythaemia associated with other myeloproliferative disorders, including chronic granulocytic leukaemia, polycythaemia rubra vera and myelofibrosis. Few data exist on the use of the recombinant interferons as maintenance agents in patients with thrombocythaemia. A cohort of 22 previously untreated patients, with essential thrombocythaemia, were treated with recombinant interferon alfa-2a maintenance therapy for a minimum period of 6 months. Effective long-term control of platelet counts, without evidence of haematological toxicity, was achieved in 19/22 patients. No objective haemorrhagic or thrombotic event occurred in 298 patient-months of interferon therapy. Three patients discontinued interferon alpha therapy due to adverse side-effects. Interferon alfa-2a is an effective maintenance agent in essential thrombocythaemia and is discussed in this context.
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PMID:Maintenance therapy in the myeloproliferative disorders: the current options. 193 19

We have previously reported that the chemiluminescence (CL) response of neutrophils (PMN) from patients with polycythemia vera (PV) was abnormally low when induced by surface receptor-dependent stimuli, fMLP and leukotriene B4, but normal when elicited by phorbol myristate acetate (PMA). This study documents that this discrepancy of the CL response to fMLP and PMA remained over a wide range of stimuli concentrations, was not due to iron-deficient PV cells and was also observed with the nitroblue tetrazolium assay. Moreover, another surface receptor-dependent agonist, platelet-activating factor, conferred a significantly lower CL response in PV PMN relative to controls. Treatment with alpha interferon or GM-CSF, to increase fMLP receptors, resulted in a similar enhancement of fMLP-induced CL in PV and controls. CL was normal when induced by a number of non-surface receptor-dependent stimuli. Release of lactoferrin in response to fMLP (and PMA) was normal (as was previously reported fMLP-induced chemotaxis and adherence). Thus, this defect is highly specific for oxidative metabolism, and localized to discrete step(s) of the stimulus-response coupling for fMLP, leukotriene B4 and PAF, but conceivably not due to impairment of the dynamic interaction of fMLP with its receptor.
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PMID:Further studies of the defective stimulus-response coupling for the oxidative burst in neutrophils in polycythemia vera. 195 81

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

Interferon alfa has been used in the treatment of myeloproliferative disorders, particularly chronic myeloid leukemia, polycythemia vera, and idiopathic thrombocythemia. The effectiveness of interferon alfa in agnogenic myeloid metaplasia needs additional evaluation, although preliminary evidence suggests that it may be more efficacious when used in the cellular (ie, proliferative) phase than when the marrow is fibrotic or osteosclerotic. Cytogenetic and molecular changes after interferon alfa therapy are apparent in patients with chronic myeloid leukemia, as manifested by change in the Philadelphia chromosome and BCR-ABL gene, respectively. The exact role of interferon in prolonging the life of chronic myeloid leukemia patients, however, remains to be determined in larger studies of longer duration. Interferon treatment seems to be well tolerated, and the frequency of treatment-limiting toxicity is low. Data to date suggest that interferon alfa may be a new and effective drug for the treatment of the myeloproliferative disorders.
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PMID:Interferon in the treatment of myeloproliferative diseases. 211 94

Sixty-six adults were studied with the aim of establishing positive diagnostic criteria for myeloproliferative disease. Erythroid colony formation from peripheral blood progenitors was assayed in a serum-free culture system with the addition of recombinant human growth factors. Endogenous colonies were more frequent in myeloproliferative disease than controls. The mean number of clusters per erythroid burst (BFU-e) in cultures with erythropoietin only was lower in primary proliferative polycythemia (polycythemia vera, PPP) than controls. In PPP, primitive BFU-e demonstrated greater dependence on interleukin 3 than controls, and mature BFU-e more susceptibility to inhibition by alpha-interferon. The findings indicate an abnormal response to several different cellular messengers in PPP, and permit an effective diagnostic discrimination from non-clonal polycythemias.
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PMID:Sensitivity of erythroid progenitors to recombinant growth factors in the diagnosis of myeloproliferative disorders. 232 55

Recombinant interferon alfa, a natural product with growth inhibitory capabilities, has been demonstrated for the first time to have significant therapeutic efficacy in controlling the red cell mass in patients with the myeloproliferative disease polycythemia vera. The starting dose was 3.0 X 10(6) U three times a week, subcutaneously (SC). In three patients the dose required was 5.0 X 10(6), U five times a week, SC. Side effects were easily tolerated. The striking advantage in the use of this drug is its presumed absence of antileukemic effect. Further evaluation is necessary, but the initial responses are encouraging.
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PMID:A new treatment for polycythemia vera: recombinant interferon alfa. 204 73

Essential thrombocythaemia (ET) is a rare clonal myeloproliferative disorder characterized by a persistent increase in platelet count. The commonly used criteria for the diagnosis, except for the level of the increase in platelet count, are usually those fixed by the Polycythemia Vera Study Group. The average age of onset is around 60 years, both sexes being affected. The symptoms frequently present at diagnosis are related to microcirculatory disturbances (palms, soles, fingers). Neurological symptoms are often observed. Thrombotic complications of the large vessels are less frequent. Haemorrhagic problems are present in about 30% of patients. Bleeding time is normal in most cases, whereas platelet aggregation abnormalities are frequently found. Nil adrenaline aggregation is the most discriminative test. The clinical course is characterized by long intervals without any symptoms; thromboembolic or haemorrhagic episodes can, however, occur, mainly in uncontrolled ET. Development of terminal acute leukaemia has been reported in 34 cases. The expression of the influence of the treatments, 32P or alkylating agents, is very strong. The treatment of ET has to take in consideration the difficult compromise between balancing the necessity of preventing complications and the effects of drug toxicity. The use of recombinant alpha-interferon has recently been proposed and is under investigation. The pathogenesis of thrombocytosis in ET seems to involve an expansion in the megakaryocyte progenitor cell pool. Platelet membrane glycoprotein abnormalities and defective glycosylation of thrombospondin have been shown. Numerous other platelet abnormalities, including decreased alpha-adrenergic receptors, loss of PGD2 receptors and increased Fc receptors, have been reported. Arachidonic metabolism seems to be abnormal and lipoxygenase is defective. Most of the platelet abnormalities seem to be the result of intrinsic defects at the level of an abnormal clone of megakaryocytes. However, causal relationships between the platelet abnormalities and bleeding or thrombosis are not yet clearly demonstrated.
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PMID:Essential thrombocythaemia. 250 75

In an open prospective pilot trial, we tested the effect of recombinant interferon alpha-2 a (rIFN alpha-2 a) on thrombocytosis in myeloproliferative disorders (MPD). Since October 1986, 13 patients with MPD (4 with chronic granulocytic leukemia, 4 with polycythemia vera, 3 with essential thrombocythemia and 2 with myeloid metaplasia) were treated with rIFN alpha-2 a. Platelet counts decreased in all treated patients within 2 to 10 weeks from a median value of 1,050 x 10(9)/l (range 610-1,940 x 10(9)/l) to 340 x 10(9)/l (range 230-495 x 10(9)/l). The response was dose-dependent. In 11 patients we observed a simultaneous reduction of the white blood cell count. Six patients still continue the IFN alpha-2 a therapy. In 7 treatment was discontinued, because of chronic side effects in 3, and because of noncompliance in one. In these patients, thrombocytosis recurred after discontinuation of the therapy. These results show that rIFN alpha-2 a is effective in controlling thrombocytosis in MPD. However, the long-term benefit of interferon in these disorders remains to be established.
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PMID:Treatment of thrombocytosis in myeloproliferative disorders with interferon alpha-2a. 264 94


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