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

The National Kidney Foundation Kidney Disease Outcomes Quality Initiative and other groups support maintaining transferrin saturation (TSAT) levels above 20% and serum ferritin levels above 100 ng/ml to ensure adequate erythropoiesis in hemodialysis patients receiving erythropoietin. However, researchers have found that even patients with TSATs above 20% may still have functional iron deficiency. This article presents information that supports the fact that maintenance of TSATs between 30% and 50%, through the use of continuous intravenous iron therapy, results in improvement of anemia, reduction in erythropoietin dose requirements, and an increase in the reticulocyte hemoglobin content. The implications of these findings for clinical practice are also discussed.
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PMID:Maintaining higher TSATs and other iron indices is beneficial in management of anemic hemodialysis patients. 1214 65

Up to 10% of patients with renal disease receiving recombinant human erythropoietin (rHuEPO) therapy show poor responsiveness to the drug. Even in patients who do respond to rHuEPO, there is a marked variability in drug sensitivity. Several factors have been recognized as causing resistance to rHuEPO, notably iron deficiency, infection/inflammation, and under dialysis. However, when these factors are excluded, the wide variation in responsiveness to rHuEPO persists. The mechanism of this effect needs to be fully elucidated. One hypothesis is that patients with uraemia showing resistance to rHuEPO may have enhanced levels of immune activation, causing increased release of pro-inflammatory cytokines in the bone marrow. Uraemia is known to be a chronic inflammatory state, with some patients showing considerably increased laboratory markers of inflammation and immune activation. Chronic inflammation can modify the process of erythropoiesis, probably mediated via pro-inflammatory cytokines such as interleukin-1 (IL-1), tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma). The concept that rHuEPO resistance is due to enhanced levels of immune activity has been investigated by studying T-cell phenotypes using flow cytometry, as well as cytokine release from T cells and monocytes in 'good' and 'poor' responders to rHuEPO. Poor responders had significantly reduced CD28 expression on both CD4+ and CD8+ cells, enhanced IL-10 generation from peripheral blood mononuclear cells (PBMCs), higher plasma IL-12 levels, and increased TNF-alpha and IFN-gamma release from PBMCs. Anti-cytokine antibodies may be useful for studying inflammatory cytokine secretion from T cells in patients with renal failure. Strategies utilizing anti-cytokine therapy may prove to be a useful adjuvant in optimizing the response to rHuEPO therapy.
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PMID:Erythropoietin resistance: the role of inflammation and pro-inflammatory cytokines. 1238 57

Much has been written on the important contribution of iron deficiency toward anemia and epoetin resistance among end-stage renal disease (ESRD) patients, but there are few studies of iron status among chronic renal insufficiency (CRI) subjects not yet requiring dialysis. The National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (NKF-K/DOQI) Practice Guidelines recommend maintaining ferritin > or =100 ng/ml and transferrin saturation (TSAT) > or =20% to ensure adequate iron supply for erythropoiesis among patients with chronic kidney disease, whether or not they are dialysis-dependent. Analysis of the nationally representative data from the Third National Health and Nutrition Examination Survey (NHANES III 1988-1994) revealed that only a minority of anemic CRI subjects in the United States met these K/DOQI targets. For example, in the range of creatinine clearance (CrCl) 30 to 50 ml/min, less than one third of men with hemoglobin <12 g/dl and women with hemoglobin <11 g/dl had ferritin > or =100 ng/ml and TSAT > or =20%. In addition, TSAT levels above 20% were independently associated with higher hemoglobin levels. Such data raise the question whether the K/DOQI targets should be reevaluated. It is concluded that ferritin and TSAT targets derived from ESRD studies may not be applicable to subjects with CRI. Further studies are needed to guide optimization of iron status and hemoglobin level in the much larger CRI population.
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PMID:Iron status and hemoglobin level in chronic renal insufficiency. 1239 50

Iron deficiency is common in patients with kidney disease and is one of the primary causes for decreased response to recombinant human erthropoietin (rHuEPO) therapy. Serum ferritin and percent tranferrin saturation are regarded as the preferred indirect measurements of iron status. The National Kidney Foundation-Kidney Disease Outcome Quality Initiative (K/DOQI) guidelines recommend levels of > 100 ng/ml and > 20%, respectively. These tests, however, have practical limitations and lack sensitivity and specificity to identify "functional" iron deficiency, which can occur in the presence of normal or even increased iron stores. Newer methods of assessing iron status are becoming available, with reticulocyte hemoglobin content (CHr) showing the most promise at this time. K/DOQ1 guidelines recommend that adequacy of iron should be based on the amount of iron needed to sufficiently achieve target hemoglobin and hematocrit levels of 11-12 g/dL, or 33-36%. Studies have demonstrated for a majority of hemodialysis and some predialysis and peritoneal dialysis patients that intravenous iron therapy is necessary to improve response, thus reducing the amount of rHuEPO needed to achieve these goals. Though intravenous iron is generally regarded as safe and effective, caution should be taken in regard to acceptable amounts of supplementation and long-term effects with the potential risk of iron overload.
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PMID:Evaluation and treatment of iron deficiency in patients with kidney disease. 1245 24

Identical National Kidney Foundation Kidney Disease Outcomes Quality Initiative (K/DOQI) hematologic and iron targets apply to chronic kidney disease (CKD), peritoneal dialysis (PD), and hemodialysis (HD) patients, yet intravenous (i.v.) nondextran iron therapy is FDA approved only in HD patients. This is because oral iron has been considered adequate in CKD and PD patients, and delivering a parenteral therapy on a frequent basis to an outpatient population with notoriously poor vascular access presents logistical complexities. However, recognition of the need for more aggressive treatment of anemia in the CKD and PD population is growing. This awareness, along with the improved safety profiles of the new, nondextran irons, is tipping the risk-benefit ratio toward more widespread use of i.v. iron in these patients. This article provides a summary of the literature and of our own experience using i.v. iron therapy in CKD and PD patients. Our protocol relies on early monitoring and intervention with i.v. ferric gluconate before severe iron deficiency develops. The proactive approach allows for relatively infrequent treatments at only moderately "high" doses (250 mg) of ferric gluconate. The convergence of convenience and safety may expedite more energetic anemia prevention and treatment in PD and CKD patients.
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PMID:Intravenous iron therapy in chronic kidney disease and peritoneal dialysis patients. 1462 35

The aim of this study was to establish the prevalence of anemia in stable pediatric renal transplant recipients and to examine the association of anemia with renal function, immunosuppressants, angiotensin converting enzyme inhibitors, and growth, as well as iron, vitamin B(12), and folate stores. This is a cross-sectional study of the 50 renal transplant recipients currently followed at our center. Patient data were collected regarding hematological parameters, growth, medications, renal function, underlying renal disease, delayed graft function, episodes of rejection, and iron or erythropoietin therapy post transplantation. The mean hemoglobin level (Hb) was 110 g/l and the overall prevalence of anemia was 60%, including 30% who were severely anemic (Hb<100 g/l). There was a high rate of iron deficiency (34%) and serum iron was the parameter of iron metabolism most closely associated with anemia. Hb in patients with low serum iron was 90.7 g/l versus 114.4 g/l in those with normal serum iron ( P<0.01). Both univariate and multiple linear regression determined tacrolimus dose and creatinine clearance to be significant factors associated with anemia. Tacrolimus dose correlated with a 10 g/l reduction in Hb for every increase of tacrolimus dose of 0.054 mg/kg per day ( P=0.001). The dose of mycophenolate was positively correlated with Hb, but this was likely to be confounded by our practice of dose reduction in the setting of anemia. Angiotensin converting enzyme inhibitor use was not associated with anemia. Severely anemic patients tended to be shorter, with a mean Z-score for height of -1.8 compared with -0.9 for those with normal Hb ( P=0.02). Anemia is a significant and common problem in pediatric renal transplant patients. Deteriorating renal function is an important cause, but other factors like iron deficiency and immunosuppression are involved. Definition of iron deficiency is difficult and serum iron may be a valuable indicator. Medication doses, nutritional status, need for erythropoietin and iron, as well as poor graft function and growth require systematic scrutiny in the care of the anemic renal transplant recipient.
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PMID:Anemia in pediatric renal transplant recipients. 1500 19

Iron-deficiency anemia is commonly encountered in patients with end-stage renal disease (ESRD) requiring chronic hemodialysis and can occur as a result of blood loss from frequent laboratory tests, blood retention in the dialysis tubing and dialyzer, gastrointestinal (GI) bleeding, repeated access surgery, poor oral iron intake and/or absorption, and low protein diets (Sakiewicz, 1998; Eschbach, 1999). Further compounding the deficiency is the use of recombinant human erythropoietin (EPO), which stimulates erythropoiesis to abnormally high levels and leads to functional iron deficiency in up to 90% of patients (Macdougall, 1995; Sunder-Plassmann, 1997).
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PMID:Implementing an i.v. iron maintenance regimen protocol in a hemodialysis practice. 1568 30

The medical care of renal anaemia has received much attention over the past decade, as nephrologists have recognized the increased therapeutic value of erythropoiesis-stimulating agents. The European Best Practice Guidelines and the US National Kidney Foundation's Kidney Disease Outcome Quality Initiative Guidelines have provided evidence-based advice on the optimal treatment of renal anaemia, and have recommended a target haemoglobin (Hb) level of 11 g/dl or 11-12 g/dl. Achieving this target Hb level has been shown to improve quality of life and reduce the rate of hospitalization; there is also good evidence to suggest that achieving adequate Hb levels reduces morbidity and mortality in patients with end-stage renal disease. In recent years, a number of factors have been identified that may counteract the positive action of epoetin therapy. These treatment-influencing factors include inadequate haemodialysis, absolute and functional iron deficiency, anticoagulant use, inflammation and infection. Each factor on its own may result in a substantial decrease in Hb levels, or an increase in epoetin requirements of up to 100%. Therefore, optimal and cost-effective treatment can only be achieved by adequately managing all of the factors that potentially can influence anaemia in patients with chronic kidney disease. Large-scale, cross-sectional surveys, such as the European Survey on Anaemia Management and the Dialysis Outcomes and Practice Patterns Study, have shown that there is still room for improving the efficacy and efficiency of anaemia therapy. The Optimal Treatment of Renal Anaemia (OPTA) initiative aims to help both physicians and nurses improve renal anaemia management by "translating" the standards set in published guidelines into practical clinical advice.
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PMID:Optimal treatment of renal anaemia (OPTA): improving the efficacy and efficiency of renal anaemia therapy in haemodialysis patients receiving intravenous epoetin. 1582 27

Normochromic normocytic anemia is common in children with chronic renal failure (CRF) when their glomerular filtration rate is below 35 ml/min/1.73 m2 BSA, but it may develop earlier in some forms of renal disease. An inadequate erythropoiesis due to insufficient erythropoietin synthesis in the kidneys is the main cause of renal anemia. Other reasons include reduced red blood cell lifespan, chronic blood loss, iron deficiency, inhibitors of erythropoiesis, and malnutrition. The presence of anemia contributes to many of the symptoms of uremia, including decreased appetite, decreased energy, poor cardiac function, and poor school performance. Therefore, correction of anemia dramatically improves the life of the child with CRF. Presently, the goal of anemia management is to maintain hematocrit concentrations at 33% to 36% and a hemoglobin concentration of at least 11 g/L. This can be accomplished by intravenous or subcutaneous administration of recombinant erythropoietin (rHuEPO, 100-300 U/kg/week) and iron preparations. If adequate iron stores cannot be maintained with oral therapy (2-3, max 6 mg/kg/day), intravenous iron should be administered. In order to optimize anemia management in children with CRF, future research should be concentrated on the normalization of hemoglobin early in the course of CRF, and the long-term effects on the child's development.
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PMID:Management of renal anemia. 1588 63

Current guidelines give evidence-based advice on how best to manage anaemia in patients with renal disease, but these guidelines do not consider individual patient needs, so tailoring anaemia management to each patient still remains a challenge for the treating physician. Two case studies are described that illustrate some of the key factors that need to be considered. The first case emphasizes that haemoglobin (Hb) targets recommended in current guidelines may not suit all patients. The patient had been stably maintained on subcutaneous epoetin therapy with an average Hb concentration of >13.0 g/dl because he developed angina symptoms when his Hb level fell to 12.2 g/dl. Iron deficiency was identified as the likely cause of falling Hb in this patient. After the patient's iron supplementation was increased, his Hb level was normalized back to >13.0 g/dl without increasing the epoetin dose, and the angina symptoms were resolved. The second case involved a pre-dialysis patient with diabetes, who required a higher dose of epoetin after beginning concomitant antihypertensive treatment with an angiotensin-converting enzyme inhibitor. Previously, the treatment of renal anaemia in pre-dialysis patients has not been the focus of attention. Two ongoing randomized controlled trials have been designed to study early initiation of epoetin treatment in pre-dialysis patients and will provide much needed information in this area.
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PMID:Individualizing anaemia treatment: a discussion of case histories. 1595 26


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