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)

We assessed the diagnostic value of determinations of serum levels of immunoreactive erythropoietin in 90 patients referred for the investigation of a raised packed red-cell volume (hematocrit) and possible erythrocytosis (a red-cell volume greater than that predicted by weight, body-surface area, or both). The mean values for erythropoietin were 16 mIU per milliliter (range, 8 to 22) in patients with polycythemia rubra vera (n = 24), 30 mIU per milliliter (range, 14 to 123) in patients with secondary erythrocytosis (n = 12), 27 mIU per milliliter (range, 13 to greater than 400) in patients with erythrocytosis of unknown origin (n = 19), and 25 mIU per milliliter (range, 18 to 35) in normal controls (n = 25). The values in the patients with polycythemia rubra vera were lower than those in the other three groups (P less than 0.01, P less than 0.05, and P less than 0.0001, respectively). In subjects with an increased packed red-cell volume but without erythrocytosis (n = 35), the levels of serum erythropoietin were the same as those in normal controls. Among patients with erythrocytosis with an unknown cause, abnormally high serum erythropoietin levels were found in 3 of 19 subjects, and in 1 of these 3 the abnormality was intermittent. Thus, measurement of serum erythropoietin in a single sample may be misleading and may not have high discriminatory value in distinguishing between polycythemia rubra vera and secondary erythrocytosis. This assay is useful in identifying patients with secondary erythrocytosis who have inappropriate erythropoietin secretion.
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PMID:Determination of serum immunoreactive erythropoietin in the investigation of erythrocytosis. 372 21

Hemoglobin North Chicago, beta 36 [C2] Pro----Ser is a new high oxygen affinity hemoglobin variant. It was discovered in a 52-year-old male with erythrocytosis since age 20 who had been treated with different regimens for polycythemia vera including several courses of 32P. The variant is electrophoretically silent with normal stability and increased oxygen affinity (P50 16.6 mm Hg at 37 degrees C, pH 7.4). Characterization of the structure of hemoglobin North Chicago involved the use of HPLC, secondary ion mass spectral analysis of the tryptic peptides and conventional fingerprinting. Hemoglobin North Chicago manifested bizarre hydrophobicity of its beta-chains, as demonstrated by reverse phase HPLC and Triton X-100 electrophoresis. This behavior is not expected from the substitution of proline to serine. Proline residue beta 36 [C2] is one of the invariant residues of the beta-chains of all known mammals and most vertebrates. This residue is involved in the alpha 1 beta 2 contacts of hemoglobin molecule and its substitution to serine is possibly associated with conformational changes and alteration of hemoglobin function.
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PMID:Hemoglobin North Chicago (beta 36 [C2] proline----serine): a new high affinity hemoglobin. 393 24

The author provides data pertinent to the modern classification of erythrocytosis, which rests on the pathogenetic principle. The difference in the pathogenesis of erythremia and secondary erythrocytoses was proved with the help of an erythroid culture and by examination of erythropoietins, which can be thus used for diagnostic purposes. Analysis of so-called "pure" erythrocytosis has shown that this term implies different patterns of erythrocytosis from the standpoint of the pathogenesis: erythremia, secondary erythrocytoses that are difficult to diagnose, and hereditary erythrocytosis associated with erythropoietin hyperproduction. There is no evidence for the existence of the "pure" erythroid leukemia and thus the author doubts this disease entity. Analysing the different patterns of secondary absolute erythrocytosis the author discusses specific problems of their pathogenesis. Attention is paid to erythrocytosis of a tobacco smoker, to the role of obesity and concomitant action of some factors on the development of hypoxic erythrocytosis. The data are presented on the new types of erythrocytosis, on the post-transplantation one, in particular, which occurs after kidney transplantation, and finally on erythrocytosis that develops occasionally in patients on hemodialysis. Attention is paid as well to relative erythrocytoses, risk factor in the development of thrombotic complications. The problems of etiologically and pathogenetically valid therapy of secondary erythrocytoses are reviewed.
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PMID:[Secondary erythrocytoses]. 404 68

Severe erythrocytosis is associated with increased whole blood viscosity and impaired blood flow. Since a reduced blood flow will cause tissue hypoxia and since tissue hypoxia is associated with increased synthesis of erythropoietin, erythrocytosis per se should cause an increase in the rate of red cell production. This, however, does not occur and severe erythrocytosis in patients with polycythemia vera does not lead to increased synthesis of erythropoietin. We propose here that the reason for this discrepancy is that decreased blood flow to the kidneys, the site of erythropoietin synthesis, does not cause renal tissue hypoxia. The oxygen tension in the kidneys is to a great extent determined by the consumption of oxygen used for sodium reabsorption and since sodium reabsorption is roughly proportional to glomerular filtration, a decreased flow of blood should be matched by a decreased oxygen consumption leaving the tissue tension of oxygen unchanged. Consequently, the location of an oxygen sensor in the kidneys controlling erythropoietin production appears to be most fortuitous since it prevents the development of a vicious circle, with erythrocytosis causing more erythrocytosis.
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PMID:Why the kidney? 405 20

Four adolescents with polycythaemia are described where symptoms typical of the disease had already existed in childhood. Three patients fulfilled the criteria of a polycythaemia vera. In one female patient the possibility of familial erythrocytosis is discussed. Polycythaemia vera mononuclear cells formed erythroid colonies in cultures in the absence of erythropoietin. The patients were phlebotomized to maintain haematocrit readings of 40 to 45%. No case has yet progressed to myeloid metaplasia or acute leukaemia.
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PMID:Primary polycythaemia in childhood and adolescence. 620 Apr 7

Symptomatic erythrocytosis developed in a 59-year-old man with polycystic kidney disease (PKD) while he was receiving maintenance hemodialysis. Major clinical and laboratory data suggested a diagnosis of polycythemia vera (PV), despite a normal serum alkaline phosphatase level and leukocyte count. Secondary erythrocytosis, related to chronic hypoxemia and increased erythropoietin production, was excluded by appropriate laboratory studies. Despite previous documentation of secondary erythrocytosis in patients receiving hemodialysis, to my knowledge, PV has not been described in this population.
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PMID:Polycystic kidney disease and polycythemia vera. Occurrence in a patient receiving hemodialysis. 661 11

Erythroid colony formation from the bone marrow and blood of 30 patients with erythrocytosis has been studied. Seventeen patients formed spontaneous erythroid colonies. They included patients with polycythaemia vera (PV) and 4 patients who did not quite fulfil the Polycythemia Vera Study Group criteria for PV, but had suggestive evidence of a myeloproliferative disorder. Thirteen patients did not form spontaneous colonies. They included patients with secondary polycythaemia, patients with normal total red cell volume and patients with absolute pure erythrocytosis of unknown origin. All patients with PV, and none with secondary polycythaemias, had spontaneous erythroid colony formation. Three of 4 untreated and 2 of 9 treated PV patients had increased number of CFU-E colonies in bone marrow. From these results it can be concluded that erythroid progenitor cell culture is a useful differential diagnostic method in erythrocytosis patients who cannot be classified clinically under PV or secondary polycythaemias.
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PMID:Spontaneous erythroid colony formation in erythrocytosis. 662 46

Erythropoietin titers, measured by bioassay of plasma extracts in hypertransfused mice, were determined in 162 patients with absolute erythrocytosis, and the results were correlated with the clinical diagnosis. Fifty-two patients met the diagnostic criteria for polycythemia vera, and all had low or nonmeasurable erythropoietin titers. Of the remaining 110 patients, 62 were suspected clinically as having secondary polycythemia. However, 15 had low erythropoietin titers, casting doubt on the accuracy of the clinical diagnosis. The pathogenesis of the erythrocytosis in the last 48 patients was unknown, and they were designated clinically as having pure erythrocytosis. However, in 20, the erythropoietin titers were increased, and in 28, the titers were low, suggesting that they belonged to at least two different groups. Using erythropoietin titers in the classification of absolute erythrocytosis, the first group should be added to the category of patients with secondary polycythemia as a subgroup with disease due to idiopathic overproduction of erythropoietin (hypererythropoietinemia or essential erythrocytosis). The second group should be added as a subgroup of patients with primary polycythemia under the term erythremia.
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PMID:Pure erythrocytosis classified according to erythropoietin titers. 669 62

Management of hematologic disorders in older patients must often be weighed in a setting of decreased physiological reserves and concurrent illnesses. Anemia in the elderly should never be attributed to old age. Even a mild anemia in collusion with multiple physical and mental problems may tip the balance for those previously able to cope with their disabilities. Iron deficiency anemia and the anemia of chronic disease are the most common types of anemia in the elderly. Nutritional anemias due to folate or vitamin B(12) deficiency are treatable and should not be overlooked. Newer chemotherapy regimens for acute nonlymphocytic leukemia have been effective in many older patients. Decisions to treat are sometimes difficult, often depending on the aggregate of coexistent physical and mental disorders. The most prevalent type of leukemia in the elderly is chronic lymphocytic leukemia. A benign asymptomatic course requires no therapy, but aggressive disease requires treatment. Multiple myeloma should be suspected in an elderly person who has both unexplained anemia and bone pain. After definitive diagnosis, phlebotomy therapy should be considered for both polycythemia vera and secondary erythrocytosis to reduce blood viscosity and increase cerebral blood flow.
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PMID:Hematologic disorders in the elderly. 680 66

Increased marrow cellularity is well recognised in polycythaemia rubra vera (PRV), but its value in the differential diagnosis of polycythaemia is not always appreciated. In 28 patients who had marrow aspiration performed on account of a raised haemoglobin concentration or red blood cell count (RBC), marrow cellularity was assessed subjectively and also measured; a comparison was made with the white blood cell count (WBC), platelet count, presence of splenomegaly and plasma volume (PV). Marrow cellularity, particularly when measured was shown to be the most reliable method of making a positive diagnosis of polycythaemia vera; cellularity of greater than 75% makes it unnecessary to perform other investigations to exclude secondary erythrocytosis.
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PMID:Marrow cellularity in the diagnosis of polycythaemia. 682 73


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