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

Because polycythemia vera (PV) is a clonal hematopoietic stem cell disease with a trilineage hyperplasia, and interleukin-3 (IL-3) stimulates trilineage hematopoiesis, we have studied the response of highly purified PV blood burst-forming units-erythroid (BFU-E) to recombinant human IL-3 (rIL-3). Whereas the growth of normal blood BFU-E in vitro rapidly declined by 40 and 60% after 24 and 48 h of incubation without 50 U/ml of rIL-3, the growth of PV BFU-E declined by only 10 and 30% under the same conditions, demonstrating a reduced dependence on rIL-3. A reduced dependence of PV BFU-E on recombinant human erythropoietin (rEP) was also present. Dose-response experiments showed a 117-fold increase in PV BFU-E sensitivity to rIL-3, and a 6.5-fold increase in sensitivity to rEP, compared to normal BFU-E, whereas blood BFU-E from patients with secondary polycythemia responded like normal BFU-E. Endogenous erythroid colony (EEC) formation, which is independent of the addition of rEP, was reduced by 50% after erythroid colony-forming cells were generated from PV BFU-E in vitro without rIL-3 for 3 d, whereas rEP-stimulated erythroid colonies were unaffected. These studies demonstrate a striking hypersensitivity of PV blood BFU-E to rIL-3, which may be the major factor in the pathogenesis of increased erythropoiesis without increased EP concentrations.
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PMID:Polycythemia vera blood burst-forming units-erythroid are hypersensitive to interleukin-3. 199 25

We report here the performance of a recently commercialized radioimmunoassay kit for determining erythropoietin (EPO) in serum or plasma. The lower detection limit of the method was 3 U/L. Precision, analyzed by the variation coefficients between different assay runs and in the same experiment, was always less than 10%; accuracy was assessed by recovery and dilution tests. In anemic patients (hematocrit 18-39%), the concentration of EPO was logarithmically related to hematocrit. A relatively large dispersion of the results was noted, as reported by others with various RIAs. Patients with severe renal failure demonstrated a very low EPO value, whatever the degree of their anemia. In some chronic anemias resulting from malignancy, EPO concentrations were also relatively low. In the polycythemia vera group, the EPO mean was below normal for greater than 95% of the patients, whatever their clinical stage (first evaluation, relapse, or remission). In contrast, 91% of the patients with pure erythrocytosis had a normal or increased EPO value, even when the etiology was unknown. Measurement of EPO concentration may be useful for the clinical differentiation of myeloproliferative disorders and, subsequently, for their prognosis and choice of treatment.
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PMID:Radioimmunoassay of erythropoietin: analytical performance and clinical use in hematology. 208 57

In vitro cultures of erythroid progenitors and radioimmunoassay of erythropoietin (Epo) are 2 recently available techniques. It is possible to assess their relevance in various hematological disorders. Erythroid cultures can be performed in the investigation of polycythemias, pure red cell aplasias (PRCA) and refractory anemias. In primary polycythemias "spontaneous" colonies appear in vitro whereas this phenomenon is never observed in secondary polycythemias. These so called "spontaneous" colonies have been demonstrated with a lower incidence in all myeloproliferative disorders. Therefore, if the absence of spontaneous colonies does not permit us to eliminate the presence of a myeloproliferative syndrome aside from polycythemia vera, their presence does seem pathognomonic of a myeloproliferative disorder. In acquired chronic pure red cell aplasia in adults, a strong correlation is found between the in vitro growth of erythroid colonies and the results of immuno-suppressive treatment. In refractory anemias erythroid cultures do not have either diagnostic, or prognostic interest. Serum epo level does not have a high discriminatory value in distinguishing between primary and secondary erythrocytosis. Indeed in PV, the Epo level is generally low or normal, in secondary polycythemias Epo level is high or normal. There is an important overlap between the two groups. Epo level determination can have a therapeutic incidence. Administration of recombinant Epo seems justified only in patients both sufficiently anemic to warrant transfusions and in whom Epo level is low in comparison with the degree of anemia.
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PMID:Erythroid cultures and erythropoietin assay. Clinical and diagnostic value. 211 39

We report a case of erythrocytosis in a patient with end-stage renal failure on chronic hemodialysis. The patient with polycystic kidney disease had an average Hb level of 10 g/dl while on hemodialysis for 3 years. He developed erythrocytosis (Hb 17.6 g/dl) following a cadaveric renal transplantation. No signs suggesting polycythemia vera were found. Nonrenal causes of secondary erythrocytosis such as anoxia, hemoglobinopathies or tumors were excluded. Angiography showed renal artery occlusion of the native kidney. Serum erythropoietin level was 85 U/l (normal 52 +/- 31 U/l) as measured by 3H-thymidine uptake. It is suggested that ischemia caused by the renal artery thrombosis stimulated the erythropoietin production in the native polycystic kidney.
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PMID:Erythrocytosis associated with renal artery thrombosis in a patient with polycystic kidney disease on hemodialysis. 211 27

The currently available radioimmunoassay for erythropoietin (Epo) using recombinant reagents is an accurate, reproducible, sensitive and specific assay which can be used to identify whether lack of Epo is contributing to anemia and, by extension, whether therapy with recombinant Epo might be appropriate. Elevation of the serum Epo level with anemia suggests that a marrow abnormality is the cause of the anemia, while a "high" Epo level in a non-anemic or plethoric patient suggests the presence of hypoxia or autonomous Epo production. Liver disease can elevate the serum Epo level, while modest degrees of anemia do not affect it appreciably. The lowest Epo levels occur in polycythemia vera, but in a particular patient this finding is not completely diagnostic.
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PMID:Serum immunoreactive erythropoietin in health and disease. 218 37

We have recently described a new two-phase liquid culture that supports the development of human erythroid progenitors (Fibach et al., Blood 73:100, 1989). The procedure separates the erythroid burst-forming units (BFUe) from the erythroid colony-forming units (CFUe) stage and enables quantitation of the proliferation and differentiation of BFUe into CFUe. In the present study we have utilized this system to study erythroid progenitors in polycythemia vera (PV). The abnormality of the erythroid series in PV has been shown to be associated with an increased responsiveness of the progenitors to the hormone erythropoietin (Epo). A basic question in this clonal stem cell disorder is at what developmental stage this abnormality of the PV clone is phenotypically expressed. We have studied this question by comparing the development of Epo-dependent and Epo-independent CFUe from peripheral blood BFUe of the PV patient during the BFUe to CFUe transition in the liquid culture. The results indicated that both types of CFUe are generated and that in all cases tested the ratio of Epo-independent progenitors at both the BFUe and CFUe stage was similar indicating no preferential development of Epo-independent CFUe. These results suggest that the abnormality of the PV erythroid progenitors is expressed only at the CFUe level. Moreover, since the liquid culture did not contain Epo, the results also support the conclusion that BFUe do not require Epo for proliferation or differentiation into CFUe.
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PMID:Proliferation and differentiation of erythroid progenitors in liquid culture: analysis of progenitors derived from patients with polycythemia vera. 222 Jul 57

The clinical, analytical, evolutive and therapeutic aspects of 33 cases of polycythemia vera which were diagnosed according to the Polycythemia Vera Study Group criteria, are described. Mean age was 65 years with a slight predominance of females (54.5%). Hemorrhagic manifestations were the most frequent (67%) with a great number of patients with digestive manifestations consisting of GI hemorrhage, abdominal pain, portal or suprahepatic veins thrombosis. Splenomegaly was the most frequently found sign upon examination (73%). The mean hemoglobin leukocyte, and platelet levels were 18 g/dl, 16,000 mm3 and 738,000 mm3 respectively. It is note worthy the value of the erythropoietin for the differential diagnosis of secondary erythrocytosis as well as the value of the bone marrow histologic study which should be included in the diagnostic criteria of the disease. The evolution of the process is favorably altered by bleedings and chemotherapeutic cytoreduction which are often performed simultaneously.
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PMID:[A clinical and biological study of 33 cases of polycythemia vera]. 223 66

The diagnosis of polycythemia requires an accurate and independent assessment of both plasma volume and red blood cell mass. Patients with an increased red cell mass (absolute polycythemia) may be hypoxic or have an erythropoietin-secreting tumor or space-occupying lesion compressing the kidney. Those with a reduced plasma volume (relative polycythemia) most often are tobacco smokers, are taking diuretic or cardiac medications, or ingest increased quantities of caffeine-containing beverages. On the other hand, polycythemia vera is a systemic disease with multiple complications, which is best diagnosed through a complex of findings as outlined by the Polycythemia Vera Study Group.
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PMID:Polycythemia vera and other polycythemic states. 227 78

The interaction between adherent cells and red cell progenitors from peripheral blood of patients with polycythemia vera (PV), essential thrombocytosis (ET), and healthy controls was studied. Various combinations of adherent and nonadherent cells were co-cultured in a semisolid system. Adherent cells from controls, when added at low concentrations, stimulated BFU-E proliferation, whereas high concentrations (40% of total cells in the culture) caused a significant decrease in the number of BFU-E colonies in 6/8 PV patients, 4/4 ET patients, and 8/12 controls. On the other hand, low and high concentrations of adherent cells from both patients with PV and ET caused a significant increase in BFU-E from either patients or controls. Moreover, adherent cells from these patients induced endogenous BFU-E proliferation (independent of erythropoietin) in nonadherent cells of 12/12 normal controls. The results show that BFU-E from patients with PV and ET are sensitive to suppression by normal adherent cells. On the other hand, adherent cells from these patients possess stimulatory activity on BFU-E from peripheral blood at all concentrations and are devoid of the inhibitory activity. This suggests a possible defect in the functioning of adherent cells in PV and ET patients which may contribute to the abnormal regulation of hematopoiesis in these disorders.
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PMID:Effect of adherent cells on the regulation of BFU-E in patients with myeloproliferative disease. 231 5

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


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