Erythropoietin and iron

[Preoperative anemia in patients with rheumatic diseases]

A preoperative anemia is an independent risk factor for the occurrence of complications during and after surgical interventions. It is associated with an increased length of hospital stay, higher mortality and an increased use of blood transfusions. Anemia affects some 30-70% of patients suffering from inflammatory rheumatic diseases, mostly caused by iron deficiency and/or chronic inflammation. The possibilities to treat anemia in rheumatic patients were extremely limited for a long period of time as older studies showed life-threatening side effects, the need of high doses of iron supplements or the occurrence of many nonresponders. Further development of the supplements, new dosage schemes and the combination of supplements increased the efficacy and reduced the occurrence of side effects to a minimum. In addition to orthopedic surgical interventions for rheumatism that despite new therapeutic options in some cases still represent the only way to alleviate the complaints, more and more patients with inflammatory rheumatic diseases also need surgical interventions due to comorbidities. Therefore, anemia should be clarified and preoperatively treated in accordance with the new study situation, to minimize additional complications due to anemia and to increase patient safety.

Transfusion prevention using erythropoietin, parenteral sucrose iron, and fewer phlebotomies in infants born at ≤30 weeks gestation at a high altitude center: a 10-year experience

INTRODUCTION

Red blood cell transfusions in infants born at ≤30 weeks gestation are frequent. Erythropoietin therapy reduces transfusions. An increase in hematocrit is an adaptive response at high altitudes but a guaranteed source of iron is necessary for adequate erythropoiesis.

METHODS

A retrospective cohort study was done to compare red blood cell transfusion practices of the 2019 EpicLatino (EPIC) Latin America network database with a single unit at 2650 m above sea level (LOCAL). The data from LOCAL for three time periods were compared over 10 years based on changes in erythropoietin dose and fewer phlebotomies. The number of cases that received transfusions and the total number of transfusions required were compared. Adjustments were made for known risk factors using a multivariate regression analysis.

RESULTS

Two hundred and twenty-one cases in LOCAL and 382 cases from EPIC were included. Overall basic demographic characteristics were similar. In EPIC a significantly higher rate of infection (28% vs. 15%) and outborn (10% vs. 1%) was found, but less necrotizing enterocolitis (9% vs. 15%) and use of prenatal steroids (62% vs. 93%) than LOCAL (p < 0.05). EPIC patients received more transfusions (2.6 ± 3 vs. 0.6 ± 1 times) than LOCAL (p < 0.001) and received them significantly more frequently (61% vs. 25%). Within the LOCAL time periods, no statistically significant differences were found other than the need for transfusions (1st 32%, 2nd 28%, 3rd 9%, p = 0.005) and the average number of transfusions (1st 0.8 ± 1.6, 2nd 0.7 ± 1.3, 3rd 0.1 ± 0.3, p = 0.004). These differences remained significant after multivariate regression analysis and adjusting for risk variables.

CONCLUSION

The combination of erythropoietin, parenteral sucrose iron, fewer phlebotomies during the first 72 h, and delayed umbilical cord clamping seem to reduce red blood cell transfusion needs. This can be extremely important in high altitude units where higher hematocrit is desirable but may also be valuable at sea level.

Association between platelet-related hemostasis impairment and functional iron deficiency in hemodialysis patients

Hemostasis impairment and iron deficiency are relatively frequent in hemodialysis patients. Both conditions may contribute to anemia. The aim of our study was to explore possible associations between hemostasis impairment and iron deficiency by employing recently introduced methods for measurement of both conditions. Sixty-three hemodialysis patients were studied, with 30 age-matched, healthy controls. Hemostasis impairment was detected by in vitro closure time tests (collagen/epinephrine cartridge: CEPI; collagen/adenosine diphosphate (ADP) cartridge: CADP), whereas (functional) iron deficiency was measured by reticulocyte hemoglobin content (CHr) and the percentage of hypochromic red cells (HRC). We found that the patient group (N=14) with functional iron deficiency (CHr<29) had significantly delayed in vitro closure times in comparison to the patients (N=49) without functional iron deficiency. Furthermore, both types of closure time (CEPI and CADP) correlate highly significantly with CHr (P=0.002, and P=0.001). Such an association was not observed between in vitro closure time and HRC. We found a significant correlation between hemostasis impairment (measured by in vitro closure time) and iron deficiency (measured by CHr) in hemodialysis patients. This correlation has not previously been reported. It seems that in hemodialysis patients the hemostasis impairment affects (functional) iron deficiency, most likely by facilitating excessive blood loss and consequent iron deficiency. Thus, it appears that a delayed in vitro closure time along with decreased CHr may identify hemodialysis patients who suffer (occult) blood loss and/or excessive blood loss during hemodialysis procedure. The clinical value of this finding should be tested in larger studies.

Recognising anaemia and malnutrition in vascular patients with critical limb ischaemia

INTRODUCTION

Anaemia is a common problem in surgical patients. Patients with critical limb ischaemia (CLI) suffer chronic inflammation, repeated infection, require intervention, and can have a protracted hospital stay. The aims of this study were to assess anaemia and nutritional status in patients presenting with CLI.

PATIENTS AND METHODS

Two observational studies were undertaken, initially a retrospective series of 27 patients with CLI. Patient demographics, clinical details, transfusion status and in-patient laboratory haemoglobin values (Hb) were recorded. In a prospective series of 32 patients, laboratory markers to identify the cause for anaemia were assessed. Further nutritional status was assessed by records of height, weight, body mass index and a validated scoring system.

RESULTS

In the retrospective series, 15 patients (56%) were anaemic. Ten (37%) were transfused a median of 2 units (range, 2-13), a total of 35 units. Patients who were transfused had lower Hb on admission (P = 0.0019), most were anaemic on admission (90%). At discharge, most patients were anaemic (n = 23; 83%). In the prospective series of 32 patients, 20 (63%) were anaemic. Nutritional assessment was performed on 18, only seven patients were scored undernourished. This was increased to 23 by an independent assessor. Anaemia was associated with malnutrition (n = 17; P = 0.049) and an increased hospital stay (mean 25 days [SD 16] vs mean 12 days [SD 8], P = 0.0125; total 513 vs 144 bed days).

CONCLUSIONS

Anaemia and poor nutrition are common and not recognised in vascular patients presenting with critical limb ischaemia. Anaemia is associated with and increased length of hospital stay.

Iron and exercise induced alterations in antioxidant status. Protection by dietary milk proteins

Lipid peroxidation stress induced by iron supplementation can contribute to the induction of gut lesions. Intensive sports lead to ischemia reperfusion, which increases free radical production. Athletes frequently use heavy iron supplementation, whose effects are unknown. On the other hand, milk proteins have in vitro antioxidant properties, which could counteract these potential side effects. The main aims of the study were: (1) to demonstrate the effects of combined exercise training (ET) and iron overload on antioxidant status; (2) to assess the protective properties of casein in vivo; (3) to study the mechanisms involved in an in vitro model. Antioxidant status was assessed by measuring the activity of antioxidant enzymes (superoxide dismutase (SOD); glutathione peroxidase (GSH-Px)), and on the onset of aberrant crypts (AC) in colon, which can be induced by lipid peroxidation. At day 30, all ET animals showed an increase in the activity of antioxidant enzymes, in iron concentration in colon mucosa and liver and in the number of AC compared to untrained rats. It was found that Casein's milk protein supplementation significantly reduced these parameters. Additional information on protective effect of casein was provided by measuring the extent of TBARS formation during iron/ascorbate-induced oxidation of liposomes. Free casein and casein bound to iron were found to significantly reduce iron-induced lipid peroxidation. The results of the overall study suggest that Iron supplementation during intensive sport training would decrease anti-oxidant status. Dietary milk protein supplementation could at least partly prevent occurrence of deleterious effects to tissue induced by iron overload.

Diagnosis and management of iron-related anemias in critical illness

OBJECTIVE

To review of the prevalence, pathogenesis, diagnosis, and management of iron (Fe)-related anemias in critical illness.

DATA SOURCE

A MEDLINE/PubMed search from 1966 to October 2005 was conducted. References from relevant articles were manually cross-referenced with additional original articles, review articles, correspondence, and chapters from selected textbooks.

DATA EXTRACTION AND SYNTHESIS

Both Fe metabolism and erythropoiesis are affected by the inflammatory response that accompanies critical illness. As a result, many critically ill patients develop the anemia of inflammation, which may be compounded by an underlying Fe deficiency. Most commonly available markers of total body Fe detect Fe deficiency unreliably in the setting of inflammation. Among these tests, the serum transferrin receptor assay is relatively accurate in reflecting total body Fe, regardless of inflammation. Treatment options for Fe-related anemias in critical illness include Fe replacement and recombinant human erythropoietin therapy. The decision to implement these therapies is complex and centers on a critical evaluation of ability to affect anemia, morbidity, and mortality in critical illness and on the potential risks of therapy.

CONCLUSIONS

Fe deficiency anemia and the anemia of inflammation may co-exist in critical illness. Diagnosis of and differentiation between these two anemias involves careful interpretation of multiple markers of total body Fe stores. The utility of treatment with both Fe and recombinant human erythropoietin for these disorders during critical illness requires further investigation.

Anaemia after renal transplantation

Anaemia is a frequent complication among long-term renal transplant recipients. A prevalence of approximately 40% has been reported in several studies. If renal function declines to stage 5 kidney disease, the prevalence of anaemia in kidney transplants is even higher. A positive correlation between haemoglobin concentration and creatinine clearance has been reported, which is a function of endogenous erythropoietin production by the functioning graft. Inflammation related to a retained kidney graft may cause hypo-responsiveness to erythropoietic agents once kidney transplant recipients return to dialysis. Furthermore, the use of azathioprine, mycophenolate mofetil and sirolimus may be associated with post-transplant anaemia. Along with erythropoietin deficiency, depletion of iron stores is one of the major reasons for anaemia in the kidney transplant population. The proportion of hypochromic red blood cells appears to be a useful parameter to measure iron supply and utilization as well as to estimate mortality risks in kidney transplant recipients. While anaemia is an important cardiovascular risk-factor after transplantation, our data suggest that anaemia is not associated with mortality and graft loss. Nevertheless, inadequate attention is paid so far to the management of anaemia after renal transplantation. A promising future aspect for risk reduction of cardiovascular disease includes the effect of erythropoietic agents on endothelial progenitor cells.

Benefits and risks of iron therapy for chronic anaemias

Iron is used widely for the treatment of anaemias with iron-restricted erythropoiesis. This intervention can be both beneficial and detrimental depending on the type of the underlying process. While in iron deficiency anaemia (IDA), the most frequent anaemia in the world, iron is the therapy of choice, this intervention can be harmful in the anaemia of chronic disease or anaemia associated with renal failure, the most common anaemias in hospitalized adult patients in Western countries. Iron is able to negatively affect cell-mediated immune effector mechanisms directed against invading microorganisms and tumour cells while at the same time, as an essential nutrient, it can stimulate the proliferation of these unwanted cells. In addition, iron catalyses the formation of toxic radicals leading to tissue damage or the promotion of cardiovascular events. Thus, it is essential to correctly diagnose the precise cause of anaemia and to consider the benefits and hazards of targeted iron therapy.

Hemochromatosis (HFE) gene mutations in Brazilian chronic hemodialysis patients

Patients with chronic renal insufficiency (CRI) have reduced hemoglobin levels, mostly as a result of decreased kidney production of erythropoietin, but the relation between renal insufficiency and the magnitude of hemoglobin reduction has not been well defined. Hereditary hemochromatosis is an inherited disorder of iron metabolism. The importance of the association of hemochromatosis with treatment for anemia among patients with CRI has not been well described. We analyzed the frequency of the C282Y and H63D mutations in the HFE gene in 201 Brazilian individuals with CRI undergoing hemodialysis. The analysis of the effects of HFE mutations on iron metabolism and anemia with biochemical parameters was possible in 118 patients of this study (hemoglobin, hematocrit, ferritin levels, transferrin saturation, and serum iron). A C282Y heterozygous mutation was found in 7/201 (3.4%) and H63D homozygous and heterozygous mutation were found in 2/201 (1.0%) and 46/201 (22.9%), respectively. The allelic frequencies of the HFE mutations (0.017 for C282Y mutation and 0.124 for H63D mutation) did not differ between patients with CRI and healthy controls. Regarding the biochemical parameters, no differences were observed between HFE heterozygous and mutation-negative patients, although ferritin levels were not higher among patients with the H63D mutation (P = 0.08). From what we observed in our study, C282Y/H63D HFE gene mutations are not related to degrees of anemia or iron stores in CRI patients receiving intravenous iron supplementation (P > 0.10). Nevertheless, the present data suggest that the H63D mutation may have an important function as a modulating factor of iron overload in these patients.

Correction of iron-deficient erythropoiesis in the treatment of anemia of chronic disease with recombinant human erythropoietin

Anemia of chronic disease (ACD) is a frequent complication of chronic inflammation in rheumatoid arthritis (RA). Recombinant human erythropoietin (rHuEpo) has been shown to be effective in correcting ACD, although with a variable rate of nonresponders. The first aim of this trial was to improve the response to rHuEpo by parenteral iron supplementation in cases of iron-deficient erythropoiesis (IDE). An additional goal was the evaluation of the zinc protoporphyrin content of erythrocytes (ZnPP), the soluble transferrin receptor (sTrfR) serum concentration, and the hemoglobin (Hb) content of reticulocytes (CHr) in stimulated erythropoiesis as diagnostic and prognostic parameters. Thirty RA patients with ACD were treated with subcutaneous 150 IU rHuEpo/kg body weight twice weekly. Intravenous iron supplementation (200 mg iron sucrose once weekly) was added in cases of IDE (n=23), which was defined by the presence of two of three criteria: saturation of transferrin (TrfS) < or =15%, hypochromic erythrocytes (HypoE) > or =10%, and a serum ferritin (Fn) concentration < or =50 microg/l. All 28 completers met the treatment goal, with an increase of the median Hb concentration from 10.3 g/dl to 13.3 g/dl. Epo treatment and iron supplementation was safe and well tolerated in all patients. Monitoring of Fn, TrfS, and HypoE every other week allowed a successful correction of anemia. Retrospective analysis of the evaluable parameters (CHr, sTrfR, and ZnPP) revealed no additional benefit for predicting or monitoring IDE in this setting, although the one or other may be advantageous in other therapeutic situations.

Soluble transferrin receptor: a discriminating assay for iron deficiency

The distinction between iron deficiency anaemia (IDA) and the anaemia that accompanies infection, inflammation or malignancy, commonly termed the anaemia of chronic disease (ACD), is often difficult, as the conventional laboratory indices of iron status are often influenced by acute phase responses. In recent years, the soluble transferrin receptor (sTfR) has been introduced as a sensitive, early and highly quantitative new marker of iron depletion, increasing in proportion to tissue iron deficit. Unlike conventional laboratory tests, the sTfR is not an acute phase reactant and remains normal in patients with chronic disease. In this study TfR concentrations were compared with the gold standard of iron stores, bone marrow iron. The sTfR concentration was shown to be the most efficient test in predicting bone marrow iron stores in 20 patients with ACD (75% efficiency) and in 18 patients with rheumatoid arthritis (RA) (94% efficiency). Measurement of sTfR may be a useful addition in the differential diagnosis of ACD and IDA.

Effect of iron treatment on circulating cytokine levels in ESRD patients receiving recombinant human erythropoietin

BACKGROUND

Anemia in patients with end-stage renal disease (ESRD) is treated with recombinant human erythropoietin (rhEPO) often in combination with iron. However, iron catalyzes the formation of toxic radicals, which might promote vascular damage, is a nutrient for microorganisms, and negatively affects immune pathways, thus increasing the risk for severe infections.

METHODS

We investigated 28 patients on chronic hemodialysis who were randomized to receive either rhEPO alone (N = 15) or rhEPO in combination with intravenous iron (N = 13) for a period of 12 weeks. We analyzed iron therapy associated changes in cytokine patterns and endogenous radical formation.

RESULTS

Tumor necrosis factor-alpha (TNF-alpha) levels were increased in ESRD patients at study entry and then decreased significantly over time in subjects receiving additional iron, while they increased with rhEPO alone. In contrast, we found serum concentrations of the anti-inflammatory cytokine interleukin (IL)-4 to increase with iron therapy. A significant negative correlation between iron availability, as determined by transferrin saturation, and TNF-alpha levels (P = 0.008) and a positive one between transferring saturation and IL-4 (P = 0.02) pointed to the potential role of iron to induce immunologic changes. Interestingly, iron therapy resulted in a slight decrease in the amounts of endogenous peroxides, which may be referred to reduced TNF-alpha concentrations since peroxide concentrations were positively correlated to TNF-alpha levels (P = 0.046) and negatively to transferrin saturation (P = 0.02).

CONCLUSION

Iron supplementation in ESRD patients down-regulates proinflammatory immune effector pathways and stimulates the expression of the anti-inflammatory cytokine IL-4. Such a condition is detrimental for host response toward invading pathogens. However, tissue damage by radicals such as endogenous peroxides may be reduced in this condition due to impaired TNF-alpha formation.

Anemia in children after transplantation: etiology and the effect of immunosuppressive therapy on erythropoiesis

Anemia in children after renal transplantation is more common than previously appreciated. Multiple factors appear to play roles in the development of post-transplant anemia, the most common of which is absolute and/or functional iron deficiency anemia. Most experts recommend that iron limited anemias in transplant patients should be diagnosed using the same criteria as for chronic renal failure patients. Serum erythropoietin (EPO) levels are expected to normalize after a successful renal transplantation with a normal kidney function, yet both EPO deficiency and resistance have been reported. While no large controlled trials comparing the effect of different immunosuppressive agents on erythropoiesis after transplantation have been performed, generalized bone marrow suppression attributable to azathioprine (AZA), mycophenolate mofetil (MMF), tacrolimus, antithymocyte preparations has been reported. Pure red cell aplasia (PRCA) occurs rarely after transplantation and is characterized by the selective suppression of erythroid cells in the bone marrow. PRCA has been reported with the use of AZA, MMF, tacrolimus, angiotensin converting enzyme inhibitors (ACEI), but not with cyclosporine (CSA) use. Post-transplant hemolytic uremic syndrome has been reported with orthoclone anti T-cell antibody (OKT3), CSA and tacrolimus therapy. Viral infections including cytomegalovirus, Epstein-Barr virus and human parvovirus B19 have been reported to cause generalized marrow suppression. Management of severe anemia associated with immunosuppressive drugs generally requires lowering the dose, drug substitution or, when possible, discontinuation of the drug. Because this topic has been incompletely studied, our recommendation as to the best immunosuppressive protocol after renal transplantation remains largely dependent on the clinical response of the individual patient.

Iron management in hemodialysis patients: optimizing outcomes in Vicenza, Italy

The management of anemia in uremic patients undergoing hemodialysis requires the appropriate combination of erythropoietin treatment, iron supplementation, and on occasion androgen therapy. Identifying and correcting functional iron deficiency is crucial to optimizing erythropoietin efficiency. Recently, however, the trend to administer maintenance iron with resultant high serum ferritin and high transferrin saturation has led to an increase in reports of iron overload. Oral iron supplementation is inexpensive and safe, but poor patient compliance and reduced intestinal absorption may limit its efficacy. Intravenous iron, on the other hand, is effective, and its safety is related to the iron salt used. Currently available data suggest that iron saccharate may be the safest iron salt available for intravenous administration, although iron gluconate is safer than the dextran forms of intravenous iron. It should be kept in mind, however, that all forms of intravenous iron may have the potential of inducing iron overload. At this time, the levels of ferritin that define iron overload are not clearly established. The side effects of iron overload are well recognized (infections, malignancies, vascular diseases); however, no guidelines exist for safe practice. There are many markers of iron deficiency, with serum ferritin and hypochromic red cell percentage currently the best markers available in clinical practice.

Iron status and the treatment of the anemia of prematurity

Many unanswered issues regarding rhEPO therapy in prematurity remain, including which premature infants best respond to rhEPO, what the long-term effect of decreased erythrocyte transfusions is, how nutritional supplementation optimizes the effect of rhEPO, whether or not rhEpo therapy causes iron deficiency later in life, and whether or not it is safe to supplement with parenteral iron. Further study of rhEPO therapy and iron status in prematurity is necessary.

Recombinant human erythropoietin use in intensive care

OBJECTIVE

To review the literature concerning the role of recombinant human erythropoietin (rHuEPO) in reducing the need for transfusion in critically ill patients.

DATA SOURCES

Articles were obtained through searches of the MEDLINE database (from 1990 to June 2001) using the key words erythropoietin, epoetin alfa, anemia, reticulocytes, hemoglobin, critical care, intensive care, critical illness, and blood transfusion. Additional references were found in the bibliographies of the articles cited. The Cochrane library was also consulted.

STUDY SELECTION AND DATA EXTRACTION

Controlled, prospective, and randomized studies on the use of rHuEPO in critically ill adults were selected.

DATA SYNTHESIS

Anemia is a common complication in patients requiring intensive care. It is caused, in part, by abnormally low concentrations of endogenous erythropoietin and is mainly seen in patients with sepsis and multiple organ dysfunction syndrome, in whom inflammation mediator concentrations are often elevated. High doses of rHuEPO produce a rapid response in these patients, despite elevated cytokine concentrations. There have been 3 studies on rHuEPO administration in intensive care and 1 trial in acutely burned patients. Only 2 of these studies looked at the impact of rHuEPO administration on the need for transfusion.

CONCLUSIONS

Few randomized, controlled trials explore the role of rHuEPO in critical care. Only 1 was a large, randomized clinical trial, but it presents many limitations. Future outcome and safety studies comparing rHuEPO with placebo must include clinical endpoints such as end-organ morbidity, mortality, transfusion criteria, and pharmacoeconomic analysis. rHuEPO appears to provide an erythropoietic response. Optimal dosage and the real impact of rHuEPO on the need for transfusion in intensive care remain to be determined. Currently, based on the evidence available from the literature, rHuEPO cannot be recommended to reduce the need for red blood cell transfusions in anemic, critically ill patients.

Increased body iron stores in elite road cyclists

BACKGROUND

One third of French elite road cyclists were found to have hyperferritinemia on antidoping control tests performed during the Tour de France in 1998.

PURPOSE

This study was undertaken to determine whether hyperferritinemia corresponded to elevated body iron stores or not and, affirmatively, what were its mechanism, its clinical consequences, and its spontaneous course.

METHODS

83 elite road male cyclists presenting with hyperferritinemia, defined as serum ferritin level greater than 300 microg.L-1, were studied with respect to consumption of iron and other drugs, serum iron tests, HFE mutations, and hepatic iron concentration (HIC; N < 35 micromol.g-1 dry weight).

RESULTS

All cyclists were asymptomatic and had normal physical and cardiac examination. Their median (range) serum ferritin, serum iron, and transferrin saturation levels were 504 microg.L-1 (306-1671), 20 micromol.L-1 (8.5-36.3), and 39% (20-76), respectively. HIC was increased in 24/27 up to 187 micromol.g-1. Allelic frequency of the H63D mutation was increased in cyclists when compared to controls (P = 0.04). However, iron tests did not differ according to HFE genotypes. Most cyclists (89%) had been supplemented with iron. The median iron supplementation was 25.5 g (range: 1.4-336) and correlated well (P = 0.002) with serum ferritin. Evolution of serum ferritin levels did not differ whether cyclists had been continuing iron supplementation or not.

CONCLUSION

Hyperferritinemia in elite road cyclists accounted for increased body iron stores caused by and persisting after cessation of excessive iron supplementation. Even when mild, iron excess may expose to long-term complications and should be removed, at least at the time when professional cyclists retire. To prevent iatrogenic iron overload, supplementation with iron must be done according to serum ferritin follow-up and not either blindly or on the basis of serum iron determination only.

Anemia and iron deficiencies among long-term renal transplant recipients

Iron deficiency anemia after renal transplantation has not been systematically investigated. The prevalence of anemia and the indicators of iron deficiency among 438 renal transplant recipients were examined. Anemia was present in 39.7% of the patients. The prevalence of iron deficiencies, as indicated by a percentage of hypochromic red blood cells (HRBC) of >or=2.5%, was 20.1%. The majority of severely anemic patients exhibited HRBC values in the upper quartile. Positive associations of hemoglobin levels with creatinine clearance, serum transferrin levels, male gender, transferrin saturation (TSAT), polycystic kidney disease, and age were observed. Negative associations with erythropoietin therapy, use of azathioprine, serum ferritin levels, and body mass index were observed. The risk for anemia was closely related to the highest quartile of HRBC percentages (odds ratio, 2.35; 95% confidence interval, 1.48 to 3.75; P = 0.00029), whereas ferritin levels and TSAT conferred no risk for anemia. Therefore, assessment of the HRBC proportion is superior to decreased ferritin and decreased TSAT measurements for the diagnosis of iron deficiencies among renal transplant recipients.

Unanticipated favorable effects of correcting iron deficiency in chronic hemodialysis patients

BACKGROUND

Correction of anemia in hemodialysis patients is seldom completely attained, and the response of parameters other than hemoglobin concentration to anemia correction has not been evaluated in detail.

METHODS

Laboratory parameters that suggest iron deficiency occurred in 10-15% of 206 recombinant human erythropoietin (rhEPO)-treated patients. Oral iron was given for 9 months and intravenous iron thereafter on a patient-specific basis when iron deficiency was evident. Eighty-seven hemodialysis patients with data for 12 months were followed for another 12 months. A computerized information system enabled data management and analysis.

RESULTS

With oral iron, serum ferritin decreased (P < 0.001), indicating further iron depletion. With intravenous iron, hemoglobin increased, evidence of iron deficiency decreased, and less rhEPO was needed. Striking macrocytosis appeared. Serum albumin and serum creatinine/kg body weight (an index of muscle mass) increased, while blood pressure decreased. Data were reanalyzed in four mean corpuscular volume (MCV) quartiles and two ferritin subsets at study onset. Iron deficient erythropoiesis (low MCV, mean corpuscular hemoglobin [MCH], and transferrin saturation) was striking in quartile 1; low ferritin was prevalent in all quartiles. With intravenous iron, hemoglobin increased only in quartile 1, the quartile with the greatest decrease (52%) in rhEPO dose. MCV increased in all quartiles (P < 0.001). Serum albumin increased in all MCV quartiles and both ferritin subsets, but significant creatinine/kg increase and blood pressure decrease occurred only in the low-ferritin subset.

CONCLUSIONS

Macrocytosis occurred with intravenous iron replacement. The universal MCV increase suggests unrecognized, inadequately treated, folic acid deficiency unmasked by an adequate iron supply. There was also improved well being. Effects were most clearly evident in patients with deficient iron stores.

Anemia management of adult hemodialysis patients in the US results: from the 1997 ESRD Core Indicators Project

BACKGROUND

The Health Care Financing Administration's End-Stage Renal Disease (ESRD) Core Indicators Project collects clinical information on prevalent adult patients receiving in-center hemodialysis (HD) care in the United States to assess the quality of care delivered. Although hematocrit values, transferrin saturations, and iron prescription practices have improved over the last five years, we sought to determine whether continued opportunities for improvement of this domain of care exist.

METHODS

A random sample of 7292 adult in-center HD patients was selected. Dialysis facility staff provided clinical information for the period of October through December 1996 for 6858 (94%) patients; complete laboratory information was available from 4991 (73%) returned forms. Hematocrit values, transferrin saturations, serum ferritin concentrations, epoetin alfa dosing, and iron prescriptions were abstracted from patient medical records to assess anemia management practices.

RESULTS

The mean hematocrit for this cohort was 32.6 +/- 3.5%. Seventy-two percent of patients had hematocrit values> 30%. Forty-two percent had hematocrit values of 33 to 36%, and 10% were severely anemic (hematocrit <28%). Ninety-four percent of the patients received epoetin alfa intravenously (i.v.) and 6% subcutaneously. The mean weekly dose was 202.4 +/- 137.2 units/kg. The mean transferrin saturation was 27.4 +/- 12.6%; 73% of patients had a mean transferrin saturation > or = 20%. The mean serum ferritin concentration was 386 +/- 422 ng/mL; 79 and 12% of patients had a serum ferritin concentration of> 100 and> 800 ng/mL, respectively. Nine percent of the sample (N = 434) had a transferrin saturation <20% and serum ferritin concentration <100 ng/mL. Regardless of the patient's transferrin saturation, approximately three fourths of the patients received either oral or i.v. iron, and only approximately one half of the patients received i.v. iron. Of the subset of patients with transferrin saturation <20% and serum ferritin concentration <800 ng/mL, only 53% were prescribed intravenous iron. Multivariate linear regression analysis revealed that serum albumin, urea reduction ratio, age, and transferrin saturation were significantly positively associated with hematocrit. Epoetin alfa dose and serum ferritin concentration were significantly and negatively associated with the hematocrit (P < 0.001).

CONCLUSION

Although substantial improvements have been made in anemia management for adult in-center HD patients over the past five years, significant opportunities persist to improve iron prescription practices.