Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine whether the chelation of aluminium enhances the haemopoietic response to recombinant human erythropoietin (r-HuEPO), desferrioxamine (DFO) at a dose of 20-30 mg/kg was given to 7 of 17 transfusion-dependent haemodialysis patients treated with r-HuEPO (40 units/kg/dialysis i.v.). The two randomly allocated groups did not differ in age, initial haemoglobin, plasma aluminium, plasma aluminium after DFO challenge, and ferritin, but, by chance, dialysis time was longer in the DFO group (69 vs. 32 months; p = 0.02). DFO was administered for 16 +/- 4 (SE) dialyses. During this period, Hb rose faster in the DFO group, in relation to time (0.61 vs. 0.29 g/l day; p less than 0.05) and r-HuEPO dose (3.35 vs. 1.88 g/l/100 units r-HuEPO/kg; p less than 0.05). However, in the DFO group, there was a high incidence of side effects, especially visual toxicity. It is concluded that DFO enhances the effectiveness of r-HuEPO in correcting the anaemia of chronic renal failure, but the combination of DFO and r-HuEPO is unsafe under the conditions described.
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PMID:Desferrioxamine enhances the haemopoietic response to erythropoietin, but adverse events are common. 185 80

In this study we determined the serum erythropoietin (Epo) levels of 97 anaemic rheumatoid (RD) patients (Hb less than 11 g/dl) of whom 44 had serum ferritin greater than 60 micrograms/l (anaemia of chronic disorders; ACD), 26 had ferritin 20-60 micrograms/l and 27 had ferritin less than 20 micrograms/l. These results were compared with the Epo levels of 36 iron deficient controls (Hb less than 11 g/dl), 33 non-anaemic RD patients and 33 normals. The serum Epo levels of anaemic subjects were significantly higher (P less than 0.05) than those of non-anaemic patients. Despite similar Hb, the Epo results (geometric mean (confidence limits] of the ACD group (38 (32,45) mU/ml) and of RD patients with ferritin of 20-60 micrograms/l (39 (33,46)mU/ml) were significantly lower (P less than 0.05) than those of iron deficient controls (65 (52,80)mU/ml). When the Hb fell to 10 g/dl or less, the serum Epo of 13 RD patients with ferritin less than 20 micrograms/l was 65 (47,89)mU/ml, significantly lower (P less than 0.05) than that of 17 iron deficient controls (104 (78,136)mU/ml). These results justify clinical trials of recombinant human Epo in RD patients with ACD.
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PMID:Evidence for impaired erythropoietin response to anaemia in rheumatoid disease. 154 Jul 97

Recombinant human erythropoietin (rHuEpo) is an effective therapy for anaemia in most patients with end-stage renal disease (ESRD). However, there remain a minority of patients with ESRD who are resistant to the effects of rHuEpo. The present study examined the role of aluminium overload and hyperparathyroidism of the biological effects of rHuEpo. Twenty-two patients aged 26-74 (mean 53 +/- SD 15.5) received rHuEpo 50-200 U/kg per week for 16.5 +/- 8.0 months (range 3-27). Haemoglobin was maintained at 11.5-13.0 g/dl by appropriate dose adjustment. Iron supplements were provided to maintain serum ferritin greater than 200 ng/ml. The mean time to rHuEpo response (Hb greater than 2 g/dl over baseline) was 6.1 +/- 2.6 weeks. Mean pretreatment serum aluminium correlated with time to Hb response (r = 0.48; P less than 0.05) and pretreatment mean corpuscular volume (r = 0.43; P less than 0.05) but not with eventual rHuEpo maintenance dose. PTH did not correlate with either Hb response or eventual maintenance rHuEpo dose. In summary, elevated serum aluminium concentrations were associated with an initial resistance to the biological effects of rHuEpo but had no effect on long-term dose requirements. In contrast, no impact of PTH on either immediate or long-term rHuEpo dose was evident.
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PMID:The role of aluminium and parathyroid hormone in erythropoietin resistance in haemodialysis patients. 187 Jul 50

In 81 patients with failing kidney transplant, plasma levels of erythropoietin, iron, ferritin and TIBC were assessed. Progression of failure of the excretory function of the kidney transplant was accompanied by decreasing Hb and Ht values but increasing plasma levels of erythropoietin. In all examined patients presence of iron deficiency could be excluded. Results obtained in this study suggest that relative erythropoietin deficiency is the major cause of anaemia in patient with a failing kidney transplant.
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PMID:[Plasma erythropoietin levels in kidney transplant patients with impaired function of the renal graft]. 189

The effect of long-term treatment with human recombinant erythropoietin (rHuEPO) has been studied in nine end-stage renal disease patients on continuous ambulatory peritoneal dialysis (CAPD). RHuEPO was administered subcutaneously twice weekly in rising doses starting with 50 Ukg-1 body weight. After 3 months of rHuEPO haemoglobin increased from 77.7 +/- 3.2 to 112.7 +/- 5.6 g l-1 (P less than 0.03), haematocrit rose from 22.8 +/- 1.2 to 30.3 +/- 1.7% (P less than 0.01). A consistent decrease in ferritin concentration was observed during this time (P less than 0.05). After 12 months of rHuEPO treatment and increased oral iron supplementation the rises of haemoglobin and haematocrit remained stable without other significant haematological changes. The rHuEPO-induced rise in haematocrit was associated with an increased peritoneal ultrafiltration (UF) without change in diuresis and body weight. UF improved from 128 +/- 28 ml 4 h-1 dwell time to 273 +/- 45 ml 4 h-1 (P less than 0.03) within 3 months of rHuEPO treatment, and remained stable during the following study period (month 12: 253 +/- 43 ml 4 h-1, P less than 0.05). The rise in UF resulted in improved peritoneal clearances of creatinine, urea, potassium, and phosphate (P less than 0.05, month 3). No change was observed in serum urea, creatinine, calcium, and potassium. Serum phosphate increased throughout the first 6 months of rHuEPO (P less than 0.05). No severe adverse effects of rHuEPO treatment could be observed. The present results demonstrate that long-term subcutaneous administration of rHuEPO is effective in correcting renal anaemia in CAPD patients and may improve dialysis efficiency by increased peritoneal ultrafiltration.
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PMID:Effect of human recombinant erythropoietin on anaemia and dialysis efficiency in patients undergoing continuous ambulatory peritoneal dialysis. 190 54

Serum levels of transferrin receptor and erythropoietin were determined in 2 patients with hereditary hemochromatosis undergoing phlebotomy therapy. The objective of the study was to determine changes in serum transferrin receptor and serum erythropoietin occurring during therapy, and to investigate if such changes could be useful to monitor the therapy. The study showed that serum transferrin receptor, and to a lesser extent serum erythropoietin, may be better parameters than serum ferritin as indicators of when phlebotomy should be discontinued. The most sensitive parameter, however, appeared to be the serum transferrin receptor/ferritin ratio.
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PMID:Variations in serum erythropoietin and transferrin receptor during phlebotomy therapy of hereditary hemochromatosis: a case report. 191 5

In successful renal transplant recipients, transient and modest increases in endogenous erythropoietin (Epo) reverse anemia, whereas in dialysis patients, sustained administration of large doses of exogenous Epo is required for the correction of uremic anemia. Moreover, in transplant recipients, serum Epo returns to normal as the hematocrit level increases to greater than 32%. Thereafter, the hematocrit continues to increase to normal levels, while serum Epo remains in the normal range. Thus, the restoration of renal function may improve the erythropoietic response to Epo, and/or erythropoiesis in transplant patients may be stimulated by factors other than, or in addition to, Epo. In early posttransplant patients who develop erythrocytosis, serum Epo levels are often elevated, while in long-term transplant recipients, erythrocytotic patients (with normal serum ferritin) have normal serum Epo levels. On the other hand, in long-term transplant recipients with low serum ferritin, circulating Epo levels are elevated, even in patients with no overt anemia. This suggests a possible interaction between body iron store status and the synthesis of Epo.
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PMID:Interrelationship between erythropoietin and erythropoiesis: insights from renal transplantation. 192 80

As a result of the AIDS crisis, public and physician pressure have increased the utilization of autologous blood products. Attitudes about homologous blood transfusion, however, have changed dramatically in recent years. A large segment of the population undergoing elective surgery is elderly and therefore has a significant incidence of cardiovascular disease and a slow response of the erythropoietic system when acute anemia occurs. However, preoperative autologous blood donation programs require 2-5 weeks to complete; the average yield is only 2.2 units per patient. As a consequence, autologous predonation is underused and homologous transfusion cannot be completely avoided in all patients. For several years recombinant human erythropoietin (rHuEPO) has been available and has been successfully used in the treatment of patients with renal anemia. This study evaluated the effect of r-HuEPO on patients with preoperative autologous blood collection. METHODS. Ten patients of both sexes scheduled for hip arthroplasty underwent a preoperative autologous program. During a period of 23 days prior to surgery autologous blood donation was performed with 7.5 ml/kg withdrawal on four occasions, the last one 5 days prior to surgery. Five patients were randomly treated with subcutaneous injections of rHuEPO (Erypo, Cilag GmbH, Sulzbach; Distributor: Fresenius AG, Oberursel, FRG) 200 IU/kg seven times, starting 3 days after the first blood withdrawal. All patients (n = 10) received oral iron therapy with iron sulphate 304 mg/die (= 100 mg iron/die). Patients with hypertension or recent myocardial infarction were excluded from the study. The hemoglobin level before donation had to be at least 11.0 g/dl. On each study day, a complete blood count and platelets, differential, and reticulocyte count were determined by standard methods as were transferrin, ferritin, and total iron-binding capacity. Blood loss and blood consumption during and after the operation were registered. The indication for blood transfusion (autologous/homologous) was based on hemoglobin values, which were not acceptable below 8.5 g/dl. RESULTS. No side effects of rHuEPO treatment were observed. Blood loss ranged from 650 to 1100 ml intraoperatively and 400 to 950 ml postoperatively with no differences between the groups. Patients with rHuEPO had no autologous red cell concentrates (aRCC) during the operation; two of them had two units of aRCC on the 2nd postoperative day. Two of the patients in the control group had intraoperative blood transfusions (2 and 3 units aRCC, respectively); all patients in this group were transfused postoperatively: 12 of the 20 units collected were utilized. At the onset of the operation the mean hemoglobin value in patients with rHuEPO was 13.5 +/- 0.4 g/dl compared to 11.3 +/- 0.3 g/dl in the controls. Reticulocytes increased significantly during the investigation period. On the 2nd, 3rd, and 4th days of autologous blood collection and before the onset of surgery, the number of reticulocytes was significantly greater in rHuEPO patients than in the controls. Further laboratory variables such as transferrin, ferritin, and total iron-binding capacity did not change significantly during the investigation period; there were no significant differences between the two groups. DISCUSSION. The results of the present study show that rHuEPO leads to an increase in reticulocytes with maintenance of hemoglobin levels during the phlebotomy program. As a consequence, patients with anemia and particular contraindications to homologous blood derivatives (irregular antibodies, Jehovah's Witnesses) may be able to undergo major surgery successfully. The possibility of shortening the intervals between phlebotomies would seem to be of major advantage; our data also suggest that an aggressive autologous blood collection program would increase yields over present programs. In our institute a minimum hemoglobin level of 11.5 g/dl is accepted for autologous donation.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Recombinant erythropoietin in autologous blood donation]. 192 12

The aim of this study was to evaluate the effect of treatment with subcutaneous injections of recombinant human erythropoietin (rhEpo), 20-40 IU kg-1 body weight, 3 times a week, on resting blood pressure, blood pressure response during submaximal exercise, some haematological parameters, and subjective side-effects in 15 healthy male subjects. RhEpo increased both haemoglobin (Hb) concentration and haematocrit (Hct) significantly, the values for Hb being 152 +/- 4.2 g l-1 before treatment and 169 +/- 9.3 g l-1 (mean values +/- SD) after 6 weeks of rhEpo treatment (P less than 0.001). The corresponding values for Hct were 44.5 +/- 1.5% and 49.7 +/- 1.9% (P less than 0.001), respectively. The systolic and diastolic blood pressure values at rest were unchanged after rhEpo treatment. A marked increase in systolic blood pressure was observed during submaximal exercise at 200 W, the initial and final values being 177 +/- 14.2 mmHg and 191 +/- 19.5 mmHg (P less than 0.01), respectively. Heart rate during exercise at 200 W was significantly lower after rhEpo treatment than before it: 144 +/- 15 beats min-1 compared to 136 +/- 8 beats min-1 (P less than 0.001). The leucocyte count remained unchanged after rhEpo treatment, but there was a significant decrease (P less than 0.05) in the number of lymphocytes. Reticulocyte and platelet counts were unchanged. Serum (S) ferritin decreased from 87.3 +/- 41.8 mmol l-1 to 59.3 +/- 27.8 mmol l-1 after rhEpo treatment (P less than 0.001). Serum-Na, S-K, S-Ca, S-creatinine, S-bilirubin, S-aspartate aminotransferase (ASAT), S-alanine aminotransferase (ALAT), and S-lactate dehydrogenase (LD) were unchanged after rhEpo treatment. No subjective side-effects were reported. In conclusion, low doses of rhEpo increased Hb levels and Hct by more than 10% after 6 weeks. Blood pressure at rest was unchanged, but rhEpo induced a markedly accentuated blood pressure reaction during exercise. A minor decrease in the lymphocyte count was observed, but electrolyte and creatinine levels remained unchanged after rhEpo treatment.
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PMID:Effect of recombinant human erythropoietin treatment on blood pressure and some haematological parameters in healthy men. 199 37

Previous ultrastructural investigations have shown that the erythroblastic island is composed of erythroblasts at different stages of maturation which are intimately associated with a central macrophage. However, it is still unclear at which stage of erythroid differentiation this interaction occurs, mainly because of the lack of purified populations of normal erythroid progenitors [erythroid colony-forming units (CFU-E) and erythroid burst-forming units (BFU-E)] and early precursor cells (proerythroblasts) and because of our limited knowledge of their ultrastructural characteristics. In the present work we analyzed the ultrastructure of CFU-E enriched from normal human bone marrow by avidin-biotin immune rosetting and leukemic blasts of erythroid origin from two patients. Normal and leukemic CFU-Es were defined as glycophorin A (GPA)-negative blasts, devoid of rhopheocytosis, containing some ferritin molecules, either free in the cytoplasm or associated with theta-granules (theta-Gr) in the Golgi zone. Peroxidase activity was detected in the endoplasmic reticulum of these blasts. A preproerythroblast stage was identified, which corresponded to an intermediate phenotype with few GPA sites and rhopheocytosis. In contrast to hemoglobin synthesis, which was absolutely dependent on the presence of erythropoietin (Epo) during culture for 24 hours, ferritin molecules accumulated in the absence of Epo. Interestingly, leukemic CFU-E-like blasts were always in contact with bone marrow macrophages and adhesion between these cell types resisted mechanical dissociation. This result suggests that erythroid progenitors may be part of the erythroblastic island. The mechanisms involved in erythroblast-macrophage binding are still unknown, but the expression by macrophages and erythroid progenitors of receptors for fibronectin and thrombospondin (TSP), as well as their respective ligands in the case of macrophages, suggests that these molecules could be involved in the formation of the erythroblastic island.
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PMID:Association between leukemic erythroid progenitors and bone marrow macrophages. 201 49


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