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Query: UMLS:C0240066 (iron deficiency)
 7,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

When the mean corpuscular volume is normal in an anemic patient, examination of a blood smear becomes of paramount importance. When the RBCs are normochronic, normocytic, and nonpoikilocytic, the reticulocyte count determines the line of investigation. When the count is increased, either hemorrhage or hemolysis is present. When the count is not increased (ie, normal or low), the differential diagnosis includes anemias due to iron deficiency, chronic disease, renal disease, hemodilution, marrow infiltration, and marrow failure (aplastic anemia). Some morphologic clues to cause other than those pertaining to RBC morphology are discussed and illustrated. A working approach to the investigation of nonpoikilocytic normochromic normocytic anemia is suggested.
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PMID:Investigation of nonpoikilocytic normochromic normocytic anemia. 41 35

The dose of recombinant human erythropoietin (r-HuEPO) required to correct the anemia of end-stage renal disease (ESRD) varies among patients. The response to r-HuEPO is impaired if absolute or relative iron deficiency exists. Aluminum may cause a microcytic anemia in patients with ESRD, but the mechanism remains incompletely defined. Twenty-two patients in the Canadian Multicentre EPO trial were studied for 6 months. In this randomized double-blind placebo-controlled trial, free erythrocyte protoporphyrin (FEP) was used as an indicator of iron-deficient deficient erythropoiesis. The relationship of FEP to the estimates of iron availability (serum iron, transferrin saturation, ferritin) and iron utilization (corrected reticulocyte count, hemoglobin) was evaluated by multiple linear regression analysis. The effect of aluminum on FEP was evaluated by adjusting the statistical model for this variable. All patients were iron replete as assessed by serum ferritin. FEP was not related to serum aluminum before administration of r-HuEPO, but it was significantly correlated with aluminum in the treated group. In hemodialysis patients treated with r-HuEPO, the proportion of the variability explained by the parameters of iron utilization and iron availability was 0.27. The effect of aluminum increased this to 0.59. In hemodialysis patients not receiving r-HuEPO, the proportion of variability in FEP explained by the model increased from 0.16 to 0.28 by adjusting for aluminum. The data support the hypothesis that aluminum interferes with the bioavailability of stored iron for erythropoiesis and thus may result in a microcytic anemia in patients with ESRD or may blunt their response to r-HuEPO therapy.
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PMID:Bioavailability of iron in hemodialysis patients treated with erythropoietin: evidence for the inhibitory role of aluminum. 223 35

The quantitative variation among patients in their response to erythropoietin can be explained, in part, by factors that can independently cause anemia in patients with end-stage renal disease. Aluminum can blunt the effect of erythropoietin, in part by interfering with iron bioavailability. This inhibitory effect cannot be completely overcome by aggressive ferrotherapy, but can be reversed with aluminum chelation therapy. A patient is described who developed hematological evidence of aluminum excess after being treated with erythropoietin. The biochemical evidence of functional iron deficiency and the response to aluminum chelation therapy support the hypothesis that the inhibitory effect of aluminum on erythropoiesis is mediated by the interference of aluminum with the bioavailability of iron.
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PMID:The role of aluminum in the functional iron deficiency of patients treated with erythropoietin: case report of clinical characteristics and response to treatment. 223 43

Extensive testing has proven that recombinant human erythropoietin (r-HuEPO; EPOGEN [epoetin alfa], AMGEN Inc, Thousand Oaks, CA) corrects the anemia of end-stage renal disease and eliminates the need for transfusions in virtually all patients. Patients whose hematocrit levels are less than 0.30 or who are transfusion dependent are candidates for therapy. A dosage of 50 to 150 U/kg body weight intravenously three times a week produces an increase in hematocrit by approximately 0.01 to 0.02 per week. Once the hematocrit reaches 0.30 the dose is adjusted so that a target hematocrit of 0.32 to 0.38 is maintained. Eighty percent of patients need maintenance doses of r-HuEPO of less than or equal to 150 U/kg; the other 20% of patients require larger doses. Reasons for poor responses include iron deficiency, inflammation due to surgery or infection, and osteitis fibrosa. Most patients require iron supplementation to prevent functional iron deficiency. BP increased in one third of patients, and in 3% seizures occurred during the initial phase of therapy, often associated with a sudden increase in BP. This hypertension can be controlled with medication. Increased dialyzer clotting may occur, which is prevented when heparin doses are adjusted, and dialyzer solute clearances may decrease slightly. Treatment with r-HuEPO does not elicit an antibody response. The mechanism of action of r-HuEPO is identical to that of natural erythropoietin, and therefore is an appropriate therapy for the long-term management of anemia in chronic renal failure.
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PMID:Guidelines for recombinant human erythropoietin therapy. 266 49

Erythropoietin is produced mainly by the kidneys and stimulates erythropoiesis in the bone marrow. Chronic renal failure is characterized by anemia, which is principally caused by erythropoietin deficiency. Recombinant human erythropoietin (r-hEPO) corrects the anemia of chronic renal disease and improves patient well-being, exercise tolerance, and cognitive function. The clinical pharmacology, efficacy, safety, and tolerance of r-hEPO are presented. Four major studies attest to r-hEPO's efficacy in the treatment of anemia of chronic renal disease and document potential toxicities of hypertension, iron deficiency, thrombosis, and bone pain. Careful attention to the extent of correction of the hematocrit, increased heparinization during hemodialysis therapy, and compliance with dietary restrictions may minimize the incidence and severity of adverse reactions. Resistance to r-hEPO may be due to iron deficiency, aluminum toxicity, or inflammation, including infection. Potential future uses of r-hEPO include the treatment of various other anemias, such as those seen in sickle cell anemia, rheumatoid arthritis, and autologous blood donation. Controlled clinical studies in these areas have not been reported.
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PMID:Recombinant human erythropoietin. 266 69

Most anemias can be classified using the reticulocyte count, PCV, MCV, and MCHC. Regenerative anemias are characterized by reticulocytosis. Polychromasia and increased MCV usually are present. Hemolytic mechanisms and hemorrhage should be considered in a systemic evaluation of the blood and the patient. In animals with chronic external blood loss, a microcytic, hypochromic anemia develops secondary to iron deficiency. Nonregenerative anemias generally are characterized by normocytic, normochromic erythrocytes and the lack of reticulocytosis. Patients with nonregenerative anemia should be evaluated for chronic inflammation or neoplasia, renal disease, endocrine insufficiency, or hypoplasia of the bone marrow.
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PMID:Erythrocytes. 267 33

The characteristics and uses of epoetin alfa (recombinant human erythropoietin) are described, and the issues associated with its use are discussed. The use of epoetin alfa was recently approved by FDA for the treatment of anemia associated with end-stage renal disease. Epoetin alfa acts on burst-forming and colony-stimulating units in the blood to raise hemoglobin and hematocrit levels, thus correcting the patient's anemia. It has a relatively short half-life and may be given either i.v. or s.c. Doses vary and must be adjusted according to the individual patient response. Clinical trials have involved doses ranging from 15 to 500 units/kg three times per week. Treatment causes a dose-related rise in the hematocrit, with subsequent improvement in the quality of life of dialysis patients. Adverse effects include hypertension, iron deficiency, and thrombocytosis. Additional research indicates that epoetin alfa may be effective in the correction of other uncomplicated anemias, such as those related to antineoplastic therapy. Issues facing hospital pharmacists and other health-care professionals include cost (the estimated cost of therapy is $4000 to $8000 per patient per year), appropriate use and potential misuse, use and reimbursement for indications not included in FDA-approved labeling, and restriction to particular prescribers. Because epoetin alfa does not produce therapeutic effects for at least 7 to 14 days, it is an ideal agent for formulary restriction. Epoetin alfa, like other products of biotechnology, will have substantial impact, both therapeutic and economic, on the practice of pharmacy. Hospital pharmacists need to be aware of these new therapies so that they may act quickly and decisively when issues associated with their use arise.
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PMID:Recombinant human erythropoietin. 269 Jun 6

Red blood cell volume distribution width (RDW) was obtained with the Coulter counter in 60 haemodialysis patients and 55 normal individuals. RDW tended to be higher in the former and the degree of increase was to some extent correlated with the underlying nephropathy. Although RDW failed to correlate with conventional tests of iron status, it was observed that iron administration could produce a decrease toward normal in RDW and a parallel increase in haemoglobin when the initial RDW was increased. In contrast, the response to iron was negligible in the patients with normal RDW basally. It was concluded that high RDW is an acceptable indicator of iron deficiency in haemodialysis patients.
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PMID:Red blood cell volume distribution width (RDW) in uraemic patients on chronic haemodialysis. 274 77

Treatment with recombinant human erythropoietin (r-HuEPO; EPOGEN [epoetin alfa], AMGEN Inc, Thousand Oaks, CA) rapidly corrects the anemia associated with end-stage renal disease during the acute phase of therapy and supports hematocrit levels throughout the maintenance phase. However, during the acute phase of therapy, iron deficiency will develop in most patients; it is therefore initially essential to monitor body iron stores monthly. A plasma ferritin level of less than 30 ng/mL or a transferrin saturation level of less than 20% confirms the diagnosis of iron deficiency. Microcytic, hypochromic red cell morphology appears only after prolonged iron deficiency due to inadequate monitoring and insufficient iron supplementation; alternatively, microcytosis in the presence of adequate iron stores suggests aluminum toxicity. In all patients except those with transfusional iron overload, prophylactic supplementation with ferrous sulfate (325 mg up to three times daily) is recommended. When oral supplements, which are poorly tolerated at high doses, are insufficient to meet the extraordinary needs resulting from r-HuEPO-induced erythropoiesis, intravenous iron dextran (500 to 1,000 mg administered in five to ten doses) may be required. During the maintenance phase of therapy, it may be necessary to continue iron supplementation to counteract ongoing loss of iron associated with blood loss through dialyzers and gastrointestinal bleeding. At the other extreme of iron balance, iron overload in transfusion-dependent patients, recent studies suggest that the ability of r-HuEPO to mobilize iron stores can be harnessed with therapeutic phlebotomy to reverse transfusional iron overload.
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PMID:Iron management during recombinant human erythropoietin therapy. 275 26

Anemia is one of the complications of terminal chronic renal failure that may worsen with periodical hemodialysis because of residual blood losses in the dialyzers that may be significant if clotting occurs within the circulation system. The potential iron deficiency component of the anemia has been studied in 86 patients submitted to periodic hemodialysis by measurement of hemoglobin, serum iron, transferrin saturation, total iron binding capacity, and ferritin. The following correlations were investigated: degree of anemia and type of renal disease, months on hemodialysis and hemoglobin, months on hemodialysis and serum ferritin, and liters of blood transfused and serum ferritin. Statistically significant correlations were found between months on hemodialysis and hemoglobin, and between liters of blood transfused and serum ferritin. From the correlation between serum iron and ferritin the patients could be classified in three groups: 1, with either normal or low serum iron and ferritin, candidates to iron therapy; 2, with elevated serum iron and ferritin, needing no iron treatment; and 3, with unequal changes of serum iron and ferritin, in whom iron kinetic studies are indicated in order to discover the patents that may benefit from iron therapy.
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PMID:[A study of anemia in 86 patients on hemodialysis (author's transl)]. 724 64


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