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)

The relationship between serum ferritin and tissue iron was investigated in 26 dialysis patients (17 hemodialysis patients. 9 chronic peritoneal dialysis patients) with anemia (median hemoglobin 74 g/l, range 56-92 g/l). Serum ferritin ranged from 18 to 9,435 micrograms/l (median 450 micrograms/l). Tissue iron was assessed in the liver biopsies of 4 hemodialysis patients with iron overload (serum ferritin 1,150-9,435 micrograms/l), in the muscle biopsies of 5 patients with serum ferritin 170-9,435 micrograms/l, and in bone marrow aspirations (semiquantitative assessment). The mean liver iron concentration was 15.4 +/- 8.0 micrograms Fe/mg protein (mean +/- SD), which is similar to that previously found in patients with untreated idiopathic hemochromatosis. Four patients with serum ferritin 170-620 micrograms/l had muscle iron concentrations (0.33 +/- 0.10 microgram Fe/mg protein) similar to those found in controls (0.23 +/- 0.10, means +/- SD). One patient with serum ferritin 9,435 micrograms/l had a markedly increased muscle iron concentration (1.3 micrograms Fe/mg protein). The bone marrow iron was assessed as negative in 3 patients (serum ferritin 44-85 micrograms/l), positive in 8 (serum ferritin 18-379 micrograms/l), increased in 11 patients (serum ferritin 222-4,210 micrograms/l), and was markedly increased in 2 patients (serum ferritin 4,550 and 9,435 micrograms/l). Bone marrow iron correlated significantly with serum ferritin concentrations (spearman rank correlation coefficient rho = 0.89, p < 0.001). These results show that in dialysis patients with a stable iron balance and unstimulated erythropoiesis, i.e., patients without erythropoietin treatment and parenteral iron, serum ferritin is a useful indicator of iron stores. Our findings also suggest that the relationship between tissue iron and serum ferritin levels in end-stage renal disease is altered, i.e. a relative increase in serum ferritin levels unrelated to iron stores is observed in dialysis patients.
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PMID:Serum ferritin and tissue iron in anemic dialysis patients. 938 32

To evaluate storage iron deficiency and iron-deficient erythropoiesis we determined, in a cross-sectional study of 95 patients mainly including end-stage renal disease patients (ESRD) with (32) and without rh-EPO therapy (55), the following parameters: hemoglobin, mean corpuscular red cell volume, ferritin, transferrin saturation (TS), zinc protoporphyrin (ZPP) and soluble transferrin receptor (TfR). In the dialysis group the percentage of positive samples with each marker of tissue iron supply defined as TS < 20%, ZPP > 40 mumol/mol Heme and TfR > 3.05 microgram/ml was as follows: TS 43.7% and 32.2% at a diagnostic threshold level of < 16%, ZPP 33.3% and TfR 17.2%. Manifest storage iron deficiency defined as ferritin < 30 ng/ml was observed in 5.7% of the samples while the mean ferritin concentration of the rh-Epo treated dialysis patients was 509.3 ng/ml compared to 262.5 ng/ml in the group without rh-EPO therapy. These data reflect a generous iron substitution in our series taking a TS < 20% as an intervention criterion. Looking at the different results of the three markers the best correspondence was found between ZPP and TfR resulting in a weak positive correlation (+0.64). In conclusion, we found quite different results with different assays when evaluating endogenous iron availability in our series of mainly ESRD patients in a cross-sectional study. Because a gold-standard is not defined further firm conclusions cannot be drawn from this type of study. The adequacy of the different parameters of iron metabolism including threshold levels and, consequently, the decision and route of iron substitution deserve an evaluation in a longitudinal study to characterize the best marker or marker combination in this setting.
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PMID:Transferrin receptor assay and zinc protoporphyrin as markers of iron-deficient erythropoiesis in end-stage renal disease patients. 954 1

The response to recombinant human erythropoietin (rHuEPO), 50 units/kg thrice weekly, was studied prospectively in 17 children and adolescents with end-stage renal disease who were either transfusion dependent or had hematocrits < 25%. For convenience, rHuEPO was given intravenously to 12 hemodialysis (HD) patients and subcutaneously to 5 peritoneal dialysis (PD) patients. Blood pressure, hematocrit, iron indices, and serum potassium, calcium, phosphorus, alkaline phosphatase, urea nitrogen, and intact parathyroid hormone (PTH) were monitored serially. When serum ferritin was < 100 ng/ ml during therapy, 6 patients received iron supplementation. rHuEPO therapy eliminated frequent transfusions in all patients; 11 of 17 patients reached the target hematocrit of 30%-33% by week 16 of rHuEPO, 50 units/kg thrice weekly. The 5 PD patients treated subcutaneously reached target at week 6 +/- 1; 6 HD patients treated intravenously reached target at week 11 +/- 3; 6 additional HD patients never reached target at this dose; 5 of 6 had pre-rHuEPO serum PTH levels >400 pg/ml, significantly higher than those of the other patients (P < 0.005); 3 of 6 later reached a hematocrit of 30%-33% after the rHuEPO dose was increased to 120-130 units/kg thrice weekly. We conclude that most pediatric dialysis patients can be treated successfully with rHuEPO, 50 units/kg thrice weekly, unless the serum PTH concentration is markedly elevated, in which case a higher dose is likely to be needed.
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PMID:Effect of hyperparathyroidism on response to erythropoietin in children on dialysis. 965 62

Insulin and lipid metabolism were studied in seven patients (19+/-1 years) with end-stage renal disease on continuous cycling peritoneal dialysis (CCPD) before and after 6 months of therapy with human recombinant erythropoietin (EPO) to correct anemia. Hematocrit increased from 22.2+/-1.8% to 34.8+/-1.8% (P<0.001) following EPO treatment. Serum ferritin (P<0.05) and serum iron (P<0.01) decreased significantly after anemia correction. There were no significant differences in the height, weight, anthropometric measures, or intakes of protein and total calories in the patients before and after the 6 months of EPO therapy. There were no differences in serum biochemical parameters, including 1,25-dihydroxyvitamin D3 and parathyroid hormone in these patients before and after 6 months of EPO therapy. Residual renal function and Kt/Vurea were also not different before and after 6 months of EPO therapy. The hyperinsulinemic euglycemic clamp technique was used to measure insulin sensitivity. Before EPO, insulin sensitivity was low in patients on CCPD (238+/-19 mg/m2 per min) compared with controls (320+/-30; P<0.01). After 6 months of EPO therapy, insulin sensitivity increased by 28% (305+/-26, P<0.01 vs. pre-EPO values), so that these values were no longer different from control values. The hyperglycemic clamp technique was used to measure insulin secretion. Before EPO, both early- and late-phase insulin secretion were elevated in patients on CCPD compared with controls (P<0.01 in both cases). These indices of insulin secretion decreased significantly (P<0.01) following 6 months of EPO. Before EPO, plasma triglycerides, total cholesterol, low-density lipoprotein, cholesterol, and apolipoprotein B were elevated in patients compared with controls. These lipid concentrations decreased significantly following 6 months of EPO. Thus, treatment of anemia by EPO is associated with improvements in insulin and lipid abnormalities in uremic patients on CCPD.
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PMID:Metabolic effects of erythropoietin in patients on peritoneal dialysis. 981 91

Treatment of anemia in children with end-stage renal disease (ESRD) has been greatly facilitated by the introduction of recombinant human erythropoietin (rHuEPO). A major limiting factor in the treatment of renal anemia is sufficient iron supplementation. Eight children (aged 10-17 years) receiving hemodialysis were treated with intravenous iron (1 mg/kg per week) for 3 months. Hemoglobin (Hb), hematocrit (Hct), and serum ferritin levels were measured regularly. The mean Hct increased from 25% to 30%, the mean Hb increased from 7. 8 g/dl to 9.2 g/dl, and the mean ferritin level from 200 to 395 mg/dl. The mean EPO dosage could be tapered from 6,500 IU to 6,150 IU. No adverse side-effects were noted. Hence, in this uncontrolled study intravenous iron was an effective treatment for iron deficiency during rHuEPO therapy in children with ESRD on hemodialysis.
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PMID:Intravenous iron treatment of renal anemia in children on hemodialysis. 1046 May 5

Use of erythropoietin (EPO) therapy and iron supplementation has improved the management of anemia in patients with end-stage renal disease (ESRD). As more patients receive supplemental iron, however, concerns are being raised about a potential link between iron and infection. There is biologic plausibility for this link, since iron is a growth factor for bacteria and certain host defense mechanisms are iron-sensitive. Animal models show that injection of iron leads to increased susceptibility to bacterial infection. In some studies, patients with high serum ferritin levels have reduced neutrophil function. However, these studies did not determine whether serum ferritin levels were elevated because of increased iron stores or because of infection. If infection is present, it might cause both the elevated serum ferritin levels and the neutrophil dysfunction. Several clinical studies have found an association between high serum ferritin levels and increased infectious risk. In studies that control for important covariates such as use of catheters and previous infections, the infectious risk associated with iron administration or elevated serum ferritin levels is reduced or eliminated. Collectively, these studies suggest that our current understanding of the relationship between iron and infection is incomplete and further studies are needed. There is no reason to alter current iron treatment strategies based on this literature.
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PMID:Review of issues relating to iron and infection. 1051 76

Iron deficiency limits the efficacy of recombinant human erythropoietin (rhEPO) therapy in end-stage renal disease (ESRD) patients. Functional iron deficiency occurs with serum ferritin >500 ng/ml and/or transferrin saturation (TSAT) of 20 to 30%. This study examines the effects of a maintenance intravenous iron dextran (ivID) protocol that increased TSAT in ESRD hemodialysis patients from conventional levels of 20 to 30% (control group) to those of 30 to 50% (study group) for a period of 6 mo. Forty-two patients receiving chronic hemodialysis completed a 16- to 20-wk run-in period, during which maintenance ivID and rhEPO were administered in amounts to achieve average TSAT of 20 to 30% and baseline levels of hemoglobin of 9.5 to 12.0 g/dl. After the run-in period, 19 patients randomized to the control group received ivID doses of 25 to 150 mg/wk for 6 mo. Twenty-three patients randomized to the study group received four to six loading doses of ivID, 100 mg each, over a 2-wk period to achieve a TSAT >30% followed by 25 to 150 mg weekly to maintain TSAT between 30 and 50% for 6 mo. Both regimens were effective in maintaining targeted hemoglobin levels. Fifteen patients in the control group and 17 patients in the study group finished the study in which the primary outcome parameter by intention to treat analysis was the rhEPO dose needed to maintain prestudy hemoglobin levels. Maintenance ivID requirements in the study group increased from 176 to 501 mg/mo and were associated with a progressive increase in serum ferritin to 658 ng/ml. Epoetin dose requirements for the study group decreased by the third month and remained 40% lower than for the control group, resulting in an overall cost savings in managing the anemia. Secondary indicators of iron-deficient erythropoiesis were also assessed. Zinc protoporphyrin did not change in either group. Reticulocyte hemoglobin content increased only in the study group from 28.5 to 30.1 pg. It is concluded that maintenance of TSAT between 30 and 50% reduces rhEPO requirements significantly over a 6-mo period.
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PMID:Optimization of epoetin therapy with intravenous iron therapy in hemodialysis patients. 1070 77

Cardiovascular disease remains the major cause of mortality in hemodialysis patients. Abnormal oxidative stress and impaired antioxidant defense may contribute to accelerated atherogenesis associated with uremia. As oxidative modification of lipids appears to be a prerequisite for the development of atherosclerotic lesions, lipophilic antioxidants may be protective. The aim of this study was to determine the plasma levels of lipophilic antioxidants in 82 hemodialysis patients and 30 controls and to investigate the influence of body iron status on the levels of lipophilic antioxidants. The patients were categorized into 3 groups according to their serum ferritin levels. We found that the plasma levels of lycopene, delta-tocopherol, gamma-tocopherol and retinol of hemodialysis patients were lower than those of controls. On the other hand, both absolute and lipid-normalized plasma lycopene levels were significantly reduced in those patients in the groups with higher ferritin levels as compared to those with lower ferritin levels. In addition, our study showed that the lipid-normalized plasma levels of beta-carotene and alpha-carotene of hemodialysis patients with higher ferritin levels were lower than those of the patients with lower levels. These data suggest that the plasma levels of lipophilic antioxidants are altered in end-stage renal disease on hemodialysis and may be considered as markers of oxidative stress in these patients. Most importantly, elevated serum ferritin levels may affect the levels of these lipophilic antioxidants.
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PMID:Lipophilic antioxidants and iron status in ESRD patients on hemodialysis. 1112 90

The management of anemia in adult end-stage renal disease (ESRD) patients receiving hemodialysis in dialysis facilities is examined. Clinical information was collected for a random sample of adult (age > or = 18 years) patients who received hemodialysis for ESRD between October and December 1999 and included hemoglobin concentrations, epoetin alfa doses and routes of administration, iron prescribing patterns, transferrin saturation levels, and serum ferritin concentrations. Patients whose data did not include hemoglobin concentrations with the weekly epoetin dose were excluded from the analysis. Associations by patient characteristics and geographic region were examined for clinical intermediate outcomes and epoetin alfa and iron prescribing practice patterns. Data were submitted for 8154 patients, and hemoglobin values linked to weekly epoetin alfa doses were available for 7573 of those patients. The mean hemoglobin concentration for patients in the sample was 11.4 +/- 1.3 g/dL. Sixty-seven percent of patients had mean hemoglobin values > or = 11 g/dL. Females, blacks, patients 18-44 years old, and patients receiving hemodialysis for less than six months exhibited significantly lower mean hemoglobin values despite being prescribed, on average, significantly higher epoetin alfa doses than males, whites, older patients, and patients receiving hemodialysis for six months or more (p < 0.001). There was significant regional variation in the prescribing patterns for s.c. epoetin alfa and i.v. iron (p < 0.001). Multivariable logistic regression analysis found significant associations between mean hemoglobin values > 11 g/dL and certain patient characteristics, including white race, hemodialysis for six months or longer, lower prescribed weekly epoetin alfa doses, prescription of i.v. iron, mean transferrin saturation levels > or = 20%, mean Kt/V > or = 1.2, and higher mean serum albumin values. Prescribing patterns for i.v. iron did not vary by the status of patients' iron stores. Regional and patient-specific variations in parameters of anemia management provide pharmacists with the opportunity to contribute to a multidisciplinary team approach to improve the care of hemodialysis patients.
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PMID:Current management of anemia in adult hemodialysis patients with end-stage renal disease. 1188 9

Patients with end-stage renal disease (ESRD) are at a markedly increased risk for cardiovascular complications compared with the general population. In addition to traditional cardiovascular risk factors such as diabetes mellitus, hypertension, hyperlipidaemia or cigarette smoking, a number of population-specific factors are implicated, such as anaemia, hyperhomocysteinaemia, hyperphosphataemia and vascular calcification, as well as inflammation and oxidative stress. Iron overload has been suggested to increase the cardiovascular risk in the general population. Iron supplementation is a widespread clinical practice in ESRD, especially in patients on maintenance haemodialysis (HD). Iron may therefore contribute to cardiovascular complications through effects on low-density lipoprotein oxidation and endothelial dysfunction. Although the effects of iron stores and iron therapy on cardiovascular risk are not well defined in HD patients, the 'iron hypothesis' deserves attention: serum ferritin is a marker of morbidity and mortality in HD patients, and the administration of high amounts of intravenous iron increases the risks of hospitalization and death. In contrast to intravenous iron therapy, intestinal iron absorption is regulated by body iron stores and is suppressed in the presence of infection and iron overload. Prospective studies are needed to clarify the influence of iron stores and iron therapy on overall and cardiovascular morbidity and mortality in ESRD patients.
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PMID:Iron overload and cardiovascular complications in dialysis patients. 1190 55


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