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

Serum erythropoietin (Epo) concentrations were measured by radioimmunoassay (RIA) in normal, polycythemic, and anemic dogs and cats. The serum Epo concentration in normal dogs (n = 25) ranged from 7 to 37 mU/mL (median, 20 mU/mL); and in normal cats (n = 11) ranged from 9 to 38 mU/mL (median, 18 mU/mL). Polycythemic animals (PCV > 55% in dogs, > 45% in cats) were classified as those with primary (polycythemia vera), secondary, or polycythemia of uncertain etiology. Dogs with polycythemia vera (PV, n = 8) had a median serum Epo concentration in the normal range (17 mU/mL); cats with PV (n = 7) also had a median serum Epo concentration that was within the normal range (10 mU/mL). In the category of secondary polycythemias, dogs (n = 7) (median, 30.7 mU/mL) and cats (n = 2) had normal Epo concentrations. The median serum Epo concentration was significantly decreased (P < .05) in dogs with PV compared with dogs with secondary polycythemias. The median serum Epo concentrations in dogs (n = 13) and cats (n = 5) with anemias not due to chronic renal disease were significantly increased (P < .05) compared with normal dogs and cats. In cats with anemias due to chronic renal disease (n = 5) the median serum Epo concentration was not significantly different from normal cats. The measurement of the serum EPO concentration may be useful in assessment of anemia or polycythemia but the overlap of values with the normal range in all groups evaluated limit its diagnostic use.
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PMID:Serum erythropoietin concentrations measured by radioimmunoassay in normal, polycythemic, and anemic dogs and cats. 784 80

With a newly developed enzyme linked immunosorbent assay kit TOYOBO Co. in which 2 anti-EPO monoclonal antibodies were used, we assayed EPO concentration in sera from normal adults, 168 patients with renal failure and 333 patients with hematological disorders. In the patients with renal failure, serum EPO level was normal (52.9%) or reduced (42.9%), and there was no correlation to their hematocrits. However, there was an increment in EPO concentration correlated to their severity of anemia in the most patients with hematological disorders, such as iron deficiency anemia (correlation coefficient r = -0.74), aplastic anemia (r = -0.89), leukemia (r = -0.81), and MDS (r = -0.65). On the other hand, EPO concentration in sera from all the untreated patients with polycythemia vera were significantly low level. But the concentrations of EPO from the patients successfully treated, with normal hematocrit were recovered to normal level. In the patients with secondary polycythemia, there were much varieties in EPO level. Assay of EPO in blood is important not only for diagnosis of polycythemia but also for the analysis of anemia and clinical use of EPO in vivo. The method described here is accurate and technically not complicated, and could be widely induced in most laboratories.
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PMID:[Assay of erythropoietin in serum with short term enzyme linked immunosorbent assay method--the clinical significance, Part 1: Relation to anemia in renal failure and hematological disorders]. 834 55

We conducted a prospective study on 81 consecutive patients who had a kidney transplant with graft function for over 3 months to evaluate the prevalence of erythrocytosis following renal transplantation (PTE) and its potential risk factors. True PTE was defined as a RBC mass > 120% of the theoretical value allowing for sex, weight and height. 18 patients (22.2%) developed PTE (RBC mass = 157 +/- 21%) with no evidence of polycythemia vera (PV), or secondary polycythemia due to reduced arterial oxygen, kidney or hepatic tumors. PTE was more common in males (p = 0.041) and less common in patients treated with recombinant erythropoietin (rHEPO) prior to transplantation. 18 non-polycythemic patients (Hb 12.6 +/- 1.3 g/dl) matched for sex, age and renal function were used as case controls. Fewer PTE patients were transfused post-transplantation (p = 0.026). At the time of diagnosis, mean serum EPO was normal and similar to that of controls. PTE patients had lower serum ferritin (p = 0.005) and more commonly received iron supplementation when PTE occurred (p = 0.003). Other clinical factors did not differ significantly between the two groups. Two patients had a thrombotic event, 6 recovered spontaneously and 11 were successfully treated with angiotensin-converting enzyme inhibitors (ACEI). The normalization of Hb, hematocrit and RBC mass in ACEI treated patients was accompanied by a decline in serum EPO (p = 0.008). We conclude that true erythrocytosis is prevalent in cyclosporine-treated renal transplant patients. PTE seems to be an idiopathic erythrocytosis. Pretransplant rHEPO treatment may limit PTE by blunting the increased sensitivity of erythroid precursors to EPO and iron supplementation, which stimulates the development of PTE. ACEI treatment is effective and safe.
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PMID:Factors predisposing to post-renal transplant erythrocytosis. A prospective matched-pair control study. 912 2

The term familial and congenital polycythemia encompasses a heterogeneous group of disorders with the common characteristic of an absolute increased red cell mass since birth and/or similar phenotype also present in relatives. In the last 2 decades the differential diagnosis between primary and secondary familial polycythemias became more physiologically relevant as new sensitive techniques, such as accurate measurements of serum erythropoietin (S-EPO) concentration by radioimmunoassay (RIA) or ELISA, and assessment of growth of erythroid progenitor cells in vitro became available. Consequently, correct classification of many older previous reports of familial polycythemias is difficult. While familial secondary polycythemias due to high oxygen affinity hemoglobin mutants are not infrequent and have been well delineated in terms of molecular pathophysiology and phenotype during the last 3 decades, those secondary familial polycythemias due to 2,3 DPG deficiency are very rare. Familial and congenital polycythemias with increased EPO concentration and normal arterial oxygen saturation and oxygen dissociation kinetics represent an intriguing group of disorders wherein the molecular lesions remain obscure; however, in some instances a possibility of abnormal oxygen sensing pathway involving hypoxia inducible factor-1 (HIF-1) open an intriguing yet unexplored area of hematology and biology. In contrast the primary familial and congenital polycythemia (PFCP) has been only recently recognized (the first report published in 1977). Various designations have been used in the past to describe PFCP, a rare clinical syndrome, including: benign familial erythrocytosis, polycythemia vera of childhood, primary polycythemia, pure erythrocytosis, etc. Some of these terms stressed the relatively benign, non-progressive course of the disease with a normal lifespan of affected subjects; however, the apparent benignity of some of these disorders has been questioned. These disorders are familial and/or congenital, and the clinical and laboratory evidence of secondary polycythemias must be excluded. Only about 2 dozen familial and sporadic cases with PFCP have been reported. However, the mutations of erythropoietin receptor (EPOR) found in some of families with PFCP represent the only defined molecular defect of primary polycythemic phenotypes. All reported PFCP associated EPOR mutations result in truncation of its intracytoplasmic C-terminal domain which negatively regulates the EPO/EPOR signal transduction pathway. Subjects with these mutations have decreased or normal S-EPO and increased sensitivity of erythroid progenitor cells to low EPO concentrations in in vitro assays. Mutations of other genes involved in post EPOR signaling pathway such as JAK-2, HCP and STAT 5 may also play a causative role in pathogenesis of some of PFCP families where mutation of EPOR was not found.
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PMID:"Benign erythrocytosis" and other familial and congenital polycythemias. 898 88

Of 43 elderly patients who were suspected to have polycythemia between October 1990 and July 1998, 12 patients showed an increased red cell volume measured by 51Cr-labeled red blood cells. We analyzed the clinical characteristics of the 12 patients consisted of 7 men and 5 women, with a median age of 71 (range: 57-92). Chief complaints were headaches and dizziness (3 cases), symptoms of other conditions than polycythemia (4 cases). Five patients had no symptoms. Five of 6 patients over 70 years old had no symptoms due to polycythemia. Seven cases (58%) showed splenomegaly and three cases (25%) showed hepatomegaly. Laboratory findings were as follows: WBC 9.7 +/- 3.9 x 10(3)/microliter (mean +/- SD, p < 0.02 vs normal control), Hb 17.9 +/- 4.2 g/dl (p < 0.001), Plt 39.7 +/- 26.0 x 10(4)/microliter, EPO 13.8 +/- 5.2 mU/ml (p < 0.0001), NAP score 258 +/- 114, Vit. B12 1,686 +/- 2,156 pg/ml, arterial O2 saturation more than 92% in all cases. The diagnosis of all cases was polycythemia vera according to the diagnostic criteria of Polycythemia Vera Study Group. Associated conditions included 8 cases of thrombosis (cerebral thrombosis 4, thrombophrebitis 2, myocardial infarction 1, ischemic colitis 1) and 3 cases of malignancy (esophageal cancer 1, breast cancer 1, renal cancer 1), none of which was therapy-related cancer. Six patients (50%) had only phlebotomy, three (25%) only chemotherapy, and three (25%) both phlebotomy and chemotherapy. Patients over 80 years old needed neither intensive nor continuous treatment. Only one patient died due to esophageal cancer at age 89.
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PMID:[Clinical characteristics of polycythemia vera in the elderly]. 1041 May 70

Therapeutic erythrocytapheresis (TEA) has been used in different diseases such as polycythemia vera (PV), secondary erythrocytosis or hemochromatosis as a process of the less cumbersome but more expensive phlebotomy. TEA is preferred in emergency conditions such as thrombocytosis or in conditions such as porphyria cutanea tarda (PCT) or erythropoietic porphyria when plasma exchange (PEX) is often combined with TEA to reduce extracellular levels of uroporphyrin which contribute to plasma hyperviscosity. TEA is often combined with drug therapy that varies from etoposide in PV to EPO and desferoxamine which are used to mobilize and reduce iron stores in hemochromatosis. Benefits from this combination may be more long lasting than expected. Nonetheless for TEA, there is no standard protocol and, clinical experience with this therapy remains highly anecdotal. Therapeutic red cell-exchange (TREX) has been used with much interest over the years, starting with the management of hemolytic disease of the newborn and later used to correct severe anemia in thalassemia patients thereby preventing iron overload. It has also been used for the management of complications of sickle cell disease such as priapism, chest syndrome, stroke, retinal, bone, splenic and hepatic infarction or in preparation for surgery by reducing HbS to less than 30%. Automated apheresis has also favored the use of TREX in conditions such as paroxysmal nocturnal hemoglobinuria and aniline poisoning, arsenic poisoning, Na chlorate intoxications and CO intoxications, hemoglobinopathies, autoimmune hemolytic anemia, reactions due to ABO incompatibility, in preparation for ABO incompatible bone marrow transplantation or for preventing anti-D immunization after the transfusion of D(+) cells to D(-) recipients. Another field of application has been in the emergency management of intraerythrocytic parasite infections such as malaria and babesiosis. Application of TREX may be wide but its real use remains limited. In our personal experience, in 16 years, only 167 TREX procedures have been carried out in a total of 13,747 therapeutic procedures. This represents only 1.21% of the total.
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PMID:Clinical application of therapeutic erythrocytapheresis (TEA). 1083 21

Polycythemia vera - the most frequent form of a primary erythrocytosis in adult patients - represents an extremely rare disease in pediatric and juvenile patients as do congenital primary and secondary erythrocytoses. Frequently, in patients with these diseases clinical problems do not occur before adulthood. Systematic data on clinical and laboratory evaluations as well as on treatment regimens are sparse. In addition, in the majority of cases with congenital erythrocytosis, the etiology is unknown. For those reasons, a protocol (PV-ERY-KA 03) for the systematic collection of clinical, hematological, biochemical, biological as well as treatment data of children and adolescents with polycythemia vera or congenital erythrocytosis including the hemoglobinopathies with high affinity hemoglobin, familial 2,3-BPG deficiencies, and those of unknown origin, has been developed. These data are combined with molecular analyses which focus initially on EPO-receptor and vHL-gene examination, but will later be extended into presently unexplored pathophysiologic regulatory circuits. In addition, pathophysiologic changes due to the erythrocytosis will be studied. The co-ordinated medical care for patients with those rare diseases within a collaborative trial accompanied by scientific projects is aimed at the improvement of the treatment of these patients as well as to a better understanding of the underlying biological processes.
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PMID:Congenital erythrocytosis and polycythemia vera in childhood and adolescence. 1517 60

We summarize the current knowledge on molecular alterations in myeloproliferative disorders (MPD), in particular altered in vitro responses of progenitor cells, cytokine signaling, gene expression patterns and genetic lesions. Newly characterized markers, such as altered expression of polycythemia rubra vera-1 (PRV-1) and the thrombopoietin receptor (c-MPL) as well as deletions on chromosome 20q (del20q) and loss of heterozygosity on chromosome 9p (9pLOH) provide an opportunity to diagnose and identify subpopulations of MPD patients. Furthermore, we review familial syndromes that share phenotypic features with sporadic MPD. In some of these families, mutations in the genes for thrombopoietin (TPO), c-MPL, EPO-receptor and the von Hippel-Lindau (VHL) gene have been shown to cause the disease. However, in the majority of familial cases the molecular causes remain unknown. Some of these families display clonal hematopoiesis and other features previously only found in sporadic MPD. Elucidating the molecular defect(s) in these pedigrees will likely be relevant for understanding sporadic MPD pathogenesis.
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PMID:Molecular pathogenesis of Philadelphia chromosome negative myeloproliferative disorders. 1557 13

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

An increase in Hb levels, haematocrit or the absolute number of red blood cells may be evidence of polycythemia rubra vera. Much more commonly, however, erythrocytosis is due to an underlying non-hematological disease. To establish the diagnosis of polycythemia, a secondary polyglobulia must first be excluded. If no evidence of polyglobulia is found, or if EPO levels are decreased, or splenomegaly not accountable for by portal hypertension is present, a specific diagnostic work-up must be performed by a hematologist/oncologist. This includes a bone marrow aspiration, cytological examination and molecular genetic testing.
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PMID:[Elevated Hemoglobin--polyglobulia or polycythemia?]. 1766 75


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