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 dose of recombinant human erythropoietin (r-HuEpo) required to correct anemia of end-stage renal disease varies among patients. The possible factors that interfere with the responsiveness to r-HuEpo were not completely known. In 32 patients on regular hemodialytic treatment with marked anemia (Hb 5.6 +/- 0.7 g/dl), we evaluated circulating erythroid progenitor cells [burst-forming-unit erythroid (BFU-E)], erythropoietin, ferritin, folate and 1-84-parathormone levels before r-HuEpo therapy. In 12 patients, the aluminum levels after deferoxamine were also evaluated. The possible correlation between these factors and the response to r-HuEpo therapy was then evaluated. The number of circulating (c) BFU-E was highly variable (521 +/- 447 colonies/ml of blood; normal level 742 +/- 192) and does not correlate with erythropoietin, ferritin, folate, 1-84-parathormone or aluminum levels. A direct correlation between basal cBFU-E and the responsiveness to r-HuEpo therapy was recorded while no correlation was found with the other analyzed parameters. We hypothesized that low basal cBFU-E (interleukin-3 deficiency?) could reduce the response to r-HUEpo because of failure of this hematopoietic stem cell compartment to replenish the pool of more mature erythropoietic progenitor cells during the phase of accelerated maturation induced by r-HuEpo.
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PMID:Circulating burst-forming-unit erythroid and the responsiveness to recombinant human erythropoietin in patients on regular hemodialytic treatment. 143 6

Erythropoietin was applied subcutaneously to 49 patients, 41 have been treated by hemodialysis, 3 by continuous ambulatory peritoneal-dialysis, 5 had chronic progressive renal failure. Mean initial dose of erythropoietin was 139.4 U/kg/week and maintenance dose 115.9 U/kg/week. In 43% of patients serum ferritin was decreasing during treatment, and in 20% it was low before the commencing of the treatment. During erythropoietin therapy vitamin B12 was decreasing in 22% of the patients, and the substitution was necessary in 18%. Only in 1 patient it was necessary to substitute also folic acid. There were no nonresponders among erythropoietin treated patients. Elevation of blood pressure was observed in half of the patients, hypertensive encephalopathy in 1, and thrombosis of arterio-venous fistula in 3.
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PMID:Subcutaneous erythropoietin in the treatment of renal anaemia. 145 4

Endocrine abnormalities in patients with chronic renal failure are well documented. The present study aimed to assess the influence of long-term erythropoietin (EPO) therapy on endocrine abnormalities in haemodialyzed patients. Two groups of haemodialyzed patients, each of which comprised 17 subjects, were examined. The first one treated by EPO (EPO group) while the second one did not receive this hormone (NO-EPO group). A complete biochemical and hormonal check-up was performed before and at the 3, 6, 9 and 12 months of the study period. Normal values for the estimated parameters were obtained in appropriately selected sex and age-matched healthy subjects. After EPO therapy an increase of the haematocrit value from 21.8 +/- 0.9% to 32.6 +/- 0.9% was observed which was accompanied by a significant decline of plasma ferritin and saturation of transferrin. In patients of the NO-EPO group a significant although less marked rise of the haematocrit value (21.4 +/- 0.4% to 24.2 +/- 0.6%) was also noticed. EPO therapy did not change electrolytes (Na, K, Ca, inorganic phosphate), osteocalcin, creatinine, glucose and alkaline phosphatase plasma levels as well as plasma concentrations of calcium related hormones (PTH, calcitonin, 1.25(OH)2D3) and vasopressin (AVP). EPO treatment induced a significant decline of somatotropin (HGH), prolactin (PRO), follitropin (FSH), lutropin (LH), ACTH, cortisol, plasma renin activity, aldosterone, insulin (IRI), glucagon (IR-G), pancreatic polypeptide (PP) and gastrin plasma levels and an increase of plasma estradiol, testosterone and atrial natriuretic peptide (ANP). These EPO induced endocrine alterations were restricted mostly to the first 6 months of EPO administration.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Influence of long-term erythropoietin therapy on endocrine abnormalities in haemodialyzed patients. 145 6

In conclusion, many specialized tests for the evaluation of anemia and RBC abnormalities can readily be performed in-house or by commercial laboratories. Tests include RBC indices, examination of blood smears (for morphological changes, infectious agents, basophilic stippling, and polychromasia), reticulocyte counts, iron stains, serum iron determinations, Heinz body counts, and methemoglobin tests. These diagnostic tests should routinely be used for the evaluation of hematologic abnormalities that are detected by a CBC. Accurate interpretation of test results will provide vital information on the pathophysiological and/or etiologic mechanisms of disease and point the way to successful therapeutic intervention. Failure to adequately resolve some hematologic abnormalities, particularly in breeds in which heritable disease is a consideration, may require additional tests, including serum haptoglobin, ferritin and erythropoietin measurement, or assays for RBC enzymes, such as methemoglobin reductase, PK, and PFK. These tests usually are available only through research laboratories or hematology specialists, and it is advisable to consult with a veterinary clinical pathologist for referral to the appropriate individual or laboratory.
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PMID:Specialized hematology tests. 147 Jul 72

In order to further study the relation between transferrin receptor and erythropoiesis we examined serum receptor levels in megaloblastic anemia, which is the classic example of ineffective erythropoiesis. We studied 33 patients with unequivocal cobalamin deficiency, only 22 of whom were anemic. High serum transferrin receptor levels were found in 12 patients, all of whom were anemic and had high lactate dehydrogenase (LDH) levels; in contrast, only 10 of the 21 patients with normal receptor levels were anemic. Receptor correlated most strongly with LDH (r = 0.573, p < 0.001) and, inversely, with hemoglobin values (r = -0.560, p < 0.001); it also correlated with ferritin and total bilirubin levels, but not with cobalamin, MCV or erythropoietin. No association was found with the hemolytic component of megaloblastic anemia, represented indirectly by haptoglobin levels. Changes induced by cobalamin therapy were also examined in 13 patients. Transferrin receptors rose in all 6 patients who initially had high levels and in 2 of 3 patients who had borderline levels, but not in the 4 patients with initially normal levels. The receptor levels began to rise within 1-3 days, peaked at about 2 weeks and returned to normal at about the 5th wk. The findings indicate that serum transferrin receptor levels reflect the severity of the megaloblastic anemia. The elevated receptor levels rise further with cobalamin therapy, however, as effective erythropoiesis replaces ineffective erythropoiesis, and these persist until the increased erythropoiesis returns to normal.
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PMID:Serum transferrin receptor in the megaloblastic anemia of cobalamin deficiency. 147 86

Erythrocyte ferritin may be a better estimator of iron bioavailability than the conventional markers of iron stores (serum ferritin and transferrin saturation). To investigate the accuracy of these conventional markers in uremic patients compared with erythrocyte ferritin, we studied 29 chronic hemodialysis patients on erythropoietin (EPO) therapy, 18 without EPO therapy, and 22 healthy control subjects. Apart from the red blood cell indices, serum ferritin, transferrin saturation, and erythrocyte ferritin, the analytical study included red blood cell protoporphyrin and plasma aluminum levels. The control group showed erythrocyte ferritin concentrations between 8.3 and 12.5 attograms/cell (95% confidence interval). In the EPO group, red blood cell protoporphyrin correlated negatively with erythrocyte ferritin, but not with serum ferritin or transferrin saturation. In the non-EPO group, serum ferritin, erythrocyte ferritin, and transferrin saturation did not correlate with red blood cell protoporphyrin. Even though erythrocyte ferritin correlated well with serum ferritin in the EPO group (r = 0.61, P = 0.0003), the sensitivity of normal serum ferritin levels (30 to 300 ng/mL) to discard a low erythrocyte ferritin concentration (erythrocyte ferritin less than 7 ag/cell) was 0.53, while the sensitivity of serum ferritin at levels less than 30 ng/mL to indicate an absolute iron deficiency expressed as a low erythrocyte ferritin concentration was 0.28. Only values of serum ferritin and transferrin saturation greater than 300 ng/mL and 35%, respectively, could rule out a relative iron deficiency expressed as a low erythrocyte ferritin and high red blood cell protoporphyrin concentration. Plasma aluminum levels did not correlate with red blood cell protoporphyrin or erythrocyte ferritin levels in either uremic group.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Assessment of iron status by erythrocyte ferritin in uremic patients with or without recombinant human erythropoietin therapy. 151 5

We studied the relationship between serum erythropoietin (EPO) concentration and iron status in 67 patients undergoing chronic hemodialysis. Serum concentrations of EPO were measured by RIA with recombinant human EPO. The geometric mean of the serum EPO concentration was 10.9 int. units/L (mean +/- SD range = 7.8 - 15.3 int. units/L) in hemodialysis patients, considerably lower than that in normal subjects (12.9 int. units/L). We found no significant correlation between concentrations of serum EPO and hemoglobin in hemodialysis patients, but found a significant negative correlation between serum concentrations of EPO and iron in hemodialysis patients. Moreover, we also found a significant positive correlation between the EPO concentration and the unsaturated iron-binding capacity (UIBC) in serum, and a significant negative correlation between the serum concentrations of EPO and ferritin in hemodialysis patients. Several patients who had relatively high EPO concentrations for hemodialysis patients also had low iron concentrations, high UIBC values, and low ferritin concentrations. These findings suggest that iron was utilized even at these EPO concentrations, which were very low for the degree of anemia observed in the hemodialysis patients.
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PMID:Serum erythropoietin concentrations and iron status in patients on chronic hemodialysis. 154 Oct

The effect of oral iron supplementation on erythropoiesis was studied prospectively in 34 autologous blood donors. The subjects, all of whom were to undergo total hip surgery, had normal iron status at the start of the study. During the preoperative period, in which 4 units of blood were collected, 17 patients received oral iron supplementation with 287 mg of ferrous sulfate (105 mg of elemental iron/day), while 17 patients did not use any iron supplementation. Oral iron supplementation during the 4-week preoperative period lessened the decrease in ferritin levels after two phlebotomies. Neither the decrease in hemoglobin nor the increase in erythropoietin levels was influenced by iron supplementation. In both iron-supplemented and control patients, serum erythropoietin levels returned to initial values within a few days after surgery. In autologous blood donors with a normal iron status, the use of supplemental iron does not affect erythropoiesis and is insufficient to maintain iron stores.
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PMID:The effect of oral iron supplementation on erythropoiesis in autologous blood donors. 141 90

Eleven anemic children and adolescents with a median age of 14 years (range six months-20 years) on chronic hemodialysis were treated with recombinant human erythropoietin (rHuEPO) intravenously three times a week for an average of 9.2 months. After eight weeks of therapy, hematocrit rose from 20.3 +/- 1.4% to 31.7 +/- 0.7% (0.20 +/- 0.01 to 0.31 +/- 0.007, p less than 0.001, mean +/- SEM). After reaching the target hematocrit of 30% to 33% (0.30 to 0.33), doses were adjusted individually. Blood transfusions were eliminated in all but one patient. All patients experienced an increase in appetite and energy level. Serum ferritin concentrations decreased in all patients who reached target hematocrit and seven required iron supplementation. Hypertension worsened in two patients and developed in two others. One patient's vascular access clotted. Dialysis efficiency and heparin requirements during dialysis did not change significantly. We conclude that rHuEPO is safe, effective, and should be recommended as treatment for anemia in children and adolescents on hemodialysis, but close monitoring for the development of hypertension and/or iron deficiency is necessary.
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PMID:Therapy of renal anemia in children and adolescents with recombinant human erythropoietin (rHuEPO). 154 82

Studies on the influence of erythropoietin (EPO) on granulocyte or monocyte function are scant. In this study, the effect of EPO on polymorphonuclear cell (PMN) respiratory burst activity was evaluated in a double-blind, placebo-controlled study in 22 patients on maintenance hemodialysis. As an index of phagocyte respiratory burst activity, the increase in 14CO2 production from labeled glucose-1-C, after challenge with latex and zymosan, was measured on predialysis whole blood samples, before and after EPO-treatment. As controls, 56 nonuremics and 49 non-EPO-treated hemodialysis patients were evaluated. Before EPO treatment 14CO2 production was depressed to 75.7% (latex) and 54.6% (zymosan) of healthy controls (P less than 0.01). A marked improvement was observed after a mean treatment period of 4 months (latex, 115 +/- 12 to 172 +/- 14; zymosan, 178 +/- 19 to 412 +/- 36 dpm/10(3) PMN, P less than 0.01). Placebo treatment induced no changes. The improvement became more pronounced with prolongation of treatment. A significant correlation between hematocrit and 14CO2 production was observed in the EPO treatment group (latex: n = 44, r = 0.47, P less than 0.05; zymosan: n = 44, r = 0.57, P less than 0.001). No correlation was found with serum ferritin. We conclude that the depressed phagocyte glycolytic activity of hemodialyzed uremics is normalized during correction of anemia by EPO. This may be attributed to factors other than a reduction in the body iron stores.
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PMID:Correction of deficient phagocytosis during erythropoietin treatment in maintenance hemodialysis patients. 156 25


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