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Query: UMLS:C0002871 (anemia)
 52,094 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the pathophysiology of erythropoiesis in 62 patients with multiple myeloma and examined whether it would establish a rational basis for the treatment of their anaemia with recombinant human erythropoietin. Erythropoietin (Epo) production was evaluated by serum levels and erythropoiesis was quantitated by serum transferrin receptor (TfR) levels, both assessed relative to the degree of anaemia. Instead of the expected stimulation of erythropoiesis in response to anaemia, haematocrit correlated positively with marrow erythropoietic activity, indicating that the mechanism of anaemia was primarily defective red cell production. Erythropoiesis decreased and anaemia worsened significantly with advancing clinical stage. 25% of the patients had inadequate Epo production and this proportion increased to 50% in stage 3. Inappropriate Epo production was seen in 60% of patients with renal impairment but was also observed in a number of patients with normal renal function. Erythropoiesis correlated strongly with the adequacy of Epo production, particularly in advanced disease. We conclude that most myeloma patients have defective red cell production even in the absence of massive marrow infiltration and that inappropriate Epo production contributes to their anaemia.
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PMID:Erythropoiesis in multiple myeloma: defective red cell production due to inappropriate erythropoietin production. 148 51

This paper describes how Bayesian Networks can be used in combination with compartmental models to plan Recombinant Human Erythropoietin (r-HuEPO) delivery in the treatment of anemia of chronic uremic patients. Past measurements of hematocrit or hemoglobin concentration in a patient during the therapy can be exploited to adjust the parameters of a compartmental model of the erythropoiesis. This adaptive process allows more accurate patient-specific predictions, and hence a more rational dosage planning. We describe a drug delivery optimization protocol, based on our approach. Some results obtained on real data are presented.
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PMID:Drug delivery optimization through Bayesian networks. 148 38

In patients with idiopathic aplastic anaemia (n = 34) and Fanconi's anaemia (n = 8), sampled once or on several occasions, serum erythropoietin (Epo) increased with increasing severity of anaemia with apparently similar rates of increase in each group. However, after adjustment for Hb, log Epo values for the Fanconi's anaemics tended to be greater than those for the idiopathic aplastic anaemics (P < 0.01). Erythropoietin concentrations in serum samples from patients with Fanconi's and idiopathic aplastic anaemias tended to be greater than in samples from patients with anaemias from protein energy malnutrition, myelodysplasia and iron deficiency. The results suggest that there is no deficiency of erythropoietin in Fanconi's and idiopathic aplastic anaemias and that if exogenous erythropoietin is of any benefit it would need to be administered in doses large enough to induce a significant increase in log Epo. Results of the study illustrate the need to take account of the assumptions which underlie interpretation of the statistical analysis. Use of erythropoietin values in place of log Epo gives misleading conclusions demonstrable as invalid as the conditions for normality of distribution of the data and homogeneity of variances were not satisfied.
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PMID:Serum immunoreactive erythropoietin in patients with idiopathic aplastic and Fanconi's anaemias. 148 41

Patients with uraemia have a defect haemostasis caused by severe anaemia and disturbances of platelet/vessel wall interactions. Recombinant human erythropoietin (rHuEPO) treatment not only corrects anaemia, but also shortens the bleeding time. There are few reports dealing with changes of haemostasis during the first month of rHuEPO treatment. We studied platelet function after 1, 2, 4, 8, and 12 weeks of rHuEPO treatment. Erythropoietin was given to 19 dialysed patients with chronic uraemia in a dose of 2000 u subcutaneously 3 times a week. Bleeding time showed a significant fall as early as after the first week of rHuEPO treatment (p < 0.05). After the first month the bleeding time became normal in most of the patients. A significant rise in ristocetin-induced platelet aggregation was observed from the first week of therapy. It showed a strong correlation with the shortening of the bleeding time. Collagen-induced aggregation followed the same pattern but the changes were not striking. There was not significant difference in platelet adhesion, platelet aggregation in the whole blood and those induced by ADP and arachidonic acid. Platelet serotonin concentration was also showed to increase during rHuEPO therapy. We conclude that rHuEPO improves haemostasis by influencing platelet aggregation possibly involving a serotoninergic mechanism but on the other hand may increase a tendency to thrombosis.
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PMID:[Platelet aggregation during the recombinant human erythropoietin (rHuEPO) treatment of patients with uremia]. 148 23

Erythropoietin (EPO) is the main regulatory hormone for the control of erythropoiesis. EPO leads to enhanced mitosis and differentiation of erythroid precursors in the bone marrow. The major stimulus for EPO-formation is anaemia of various origin, resulting in an exponential relation between EPO levels and a decrease in haematocrit. Another important stimulus for increased EPO production is a fall of the arterial oxygen tension caused by either cardiopulmonary disorders or by a decrease of the oxygen tension in the inspiratory gas. Human erythropoietin was first isolated and purified from a large amount of urine of patients with aplastic anaemia. After the EPO gene had been cloned and expressed, biotechnically produced recombinant human erythropoietin (rHu-EPO) became available for clinical trials. EPO deficiency appears to be the major cause of renal anaemia, and hence the treatment of these patients is the most important indication for clinical use. Encouraging results in patients whose anaemia is not of renal origin have also been reported, using treatment with rHu-EPO. In preoperative autologous blood donation programmes prior to elective surgery, rHu-EPO therapy improved the amount of donated blood and ameliorated the decrease of haematocrit values. Side effects such as hypertension, thrombosis, hypercalcaemia, elevated liver enzymes were rare and were mostly related to the underlying disease.
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PMID:[Erythropoietin--physiology and therapeutic potentialities]. 148 69

The cost-effectiveness of epoetin alfa therapy for anemia in 20 patients with end-stage renal disease was retrospectively studied. Ten patients on continuous ambulatory peritoneal dialysis (CAPD) were given subcutaneous epoetin alfa as part of a multicenter, protocol-controlled study of the efficacy of epoetin alfa. Ten patients on in-center hemodialysis were given intravenous epoetin alfa as part of their routine clinical care. Change in hematocrit was used as the measure of effectiveness of epoetin alfa. Medication, laboratory, and transfusion costs were monitored for the six months preceding the initiation of epoetin alfa and the first six months of treatment. The cost of therapy increased for all patients by an average of $2722 +/- 1118; transfusion costs decreased, whereas medication and laboratory costs increased. Laboratory costs were significantly greater in CAPD patients than in hemodialysis patients during epoetin alfa therapy; no significant differences in medication costs or transfusion costs were noted between the groups. The mean increase in hematocrit for all patients was 7.4 volume percent. Following the initial change in hematocrit, further therapeutic response did not appear to be determined by increasing expenditures. Epoetin alfa was shown to be effective in treating anemia in patients with end-stage renal disease, but it was associated with higher costs of therapy.
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PMID:Cost-effectiveness of epoetin alfa therapy for anemia of end-stage renal disease. 152 88

The major stimulus for erythropoietin secretion is the circulating hemoglobin level, but other poorly understood factors appear to influence the erythropoietin level as well. Therefore, the effect of cobalamin deficiency was studied in patients who were not anemic, even though many of them had macrocytosis or metabolic deficiency of the bone marrow cells. All 15 cobalamin-deficient patients without anemia had normal erythropoietin levels, including the 4 patients with macrocytosis and 3 in whom metabolic cobalamin deficiency of the marrow cells was documented with the deoxyuridine suppression test. Moreover, among 21 cobalamin-deficient patients with anemia, the 4 least anemic patients also had normal erythropoietin levels. The other 17 anemic patients had elevated erythropoietin levels. Erythropoietin levels correlated with the severity of the anemia (r = 0.423, p less than 0.05). However, wide individual variations were observed; 4 patients with hemoglobin levels of 37-43 g/l had erythropoietin levels ranging from 69 to 3300 units/l, for example. These observations support the hypothesis that the hemoglobin level is the major, but not the sole factor that determines erythropoietin levels. As long as it does not produce anemia, however, cobalamin deficiency does not raise erythropoietin levels even when it induces metabolic deficiency of the bone marrow and macrocytosis.
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PMID:Erythropoietin levels in cobalamin deficiency: comparison of anemic and non-anemic, subtly deficient patients. 155 73

Erythropoietin, a naturally occurring human protein that stimulates red blood cell production, is secreted by the kidney in direct response to anemia and hypoxia. This mechanism is absent in those with impaired renal function; thus, those suffering from chronic renal failure may develop anemia evidenced by very low hemoglobin and hematocrit, low red blood cell count, and low reticulocyte count. Commercially available epoetin alfa recombinant may be administered intravenously or subcutaneously to reverse this deficiency.
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PMID:Clinical administration of epoetin alfa recombinant. 156 6

Erythropoietin (EPO) adjusts the red cell mass to the optimal size in order to satisfy the oxygen requirement of the body. The amount of circulating EPO is regulated by oxygen sensors in the kidney, which control the secretion of EPO through feedback signals. EPO stimulates the erythroid progenitor cells at different levels to develop into mature red blood cells. In anaemia, the serum EPO concentration, which is normally around 15 U/l, can increase 100-fold, or more. Patients with severe renal failure are unable to adapt the production of EPO in response to low haematocrit levels, and anaemia is due to a relative EPO deficiency. Studies have shown that recombinant human erythropoietin (r-HuEPO) could quickly correct anaemia in chronic renal failure by inducing a dose-dependent rise in haemoglobin and in the haematocrit level. r-HuEPO is now the standard treatment to correct severe anaemia in chronic renal failure. In recent years, r-HuEPO has been tested in other types of anaemia, some of which are fully discussed in this supplement together with various dosage regimens and routes of administration.
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PMID:Current and potential applications for erythropoietin. 157 62

In this study, erythropoietin serum levels were serially determined in eight patients with acute renal failure to get a lead on the etiology of anemia in acute renal failure and to address the relationship between erythropoietin synthesis and renal excretory performance. Erythropoietin serum levels rapidly decreased after onset of acute renal failure to values of 12.8 +/- 10.3 mU/ml compared to 16.8 +/- 9.4 mU/ml in healthy controls. After restoration of renal function, erythropoietin levels climbed slowly in six patients (15.2 +/- 5.3 mU/ml), and in relation to prolonged anemia in these patients, a relative deficiency of erythropoietin could be observed. In one patient with thrombotic thrombocytopenic purpura causing acute renal failure, the decline of erythropoietin secretion was not observed, and in a phase of the disease when plasma exchange therapy was interrupted, markedly increased erythropoietin levels, up to 182 mU/ml, were detected despite the renal failure. Focusing on erythropoietin secretion in thrombotic thrombocytopenic purpura, we followed hormone synthesis in two other patients with the same disease, one of whom had mild renal insufficiency and one had normal renal function. High erythropoietin levels of up to 205 mU/ml were found in these patients, similar to the peak levels found in the patient with complete renal failure. Plasmapheresis treatment reduced erythropoietin production in all three patients with thrombotic thrombocytopenic purpura. In summary, our study indicates that in most cases of acute renal failure, erythropoietin synthesis is compromised and may contribute to the development of anemia in renal failure and aggravate the persistence of anemia after restoration of renal function.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Erythropoietin in thrombotic thrombocytopenic purpura and acute renal failure. 160 Mar 39


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