Parenteral iron use in the management of anemia in end-stage renal disease patients

The clinical demand and supply of blood in India: A National level estimation study

Background

Estimating the clinical demand for blood and components arising in a health facility is crucial to ensure timely availability of blood. This study aims to estimate disease-specific clinical demand, supply and utilization of whole blood and components in India.

Methods

We conducted a national level cross-sectional study in five randomly selected states from five regions of the country. We included 251 public and private facilities representing primary, secondary and tertiary care facilities. We collected annual disease-specific demand, supply and utilization of blood and components using a structured tool. We estimated the national demand by extrapolating the study data (demand and beds) to the total number of estimated beds in the country.

Findings

According to the study, the total clinical demand of 251 health facilities with 51,562 beds was 474,627 whole blood units. Based on this, the clinical demand for India was estimated at 14·6 million whole blood units (95 CI: 14·59–14·62), an equivalent of 36·3 donations per 1,000 eligible populations, which will address whole blood and component requirement. The medicine specialty accounted for 6·0 million units (41·2%), followed by surgery 4·1 million (27·9%), obstetrics and gynecology 3·3 million (22·4%) and pediatrics 1·2 million (8·5%) units. The supply was 93% which is equivalent to 33·8 donations against the demand.

Conclusion

The study indicated a demand and supply gap of 2.5 donations per 1,000 eligible persons which is around one million units. The gap emphasises the need for sustained and concerted efforts from all stakeholders and for increasing the awareness about repeat voluntary non-remunerated blood donation (VNRBD); optimizing the availability of blood components through efficient blood component separation units; promoting modern principles of patient blood management and strengthening capacities of human resources in the blood transfusion system in India.

Nutrition care for chronic kidney disease during pregnancy: an updated review

Cases of chronic kidney disease (CKD), including CKD in pregnant women, have increased globally in recent years. CKD during pregnancy is associated with a higher risk of adverse outcomes, including gestational hypertension, preeclampsia, intrauterine growth restriction, and preterm birth, among others. Nutrition plays a significant role in many metabolic and physiological changes during pregnancy. Women with CKD are at increased risk of nutrition deficiencies and metabolic issues than women without CKD. Currently, we lack evidence regarding metabolic and nutritional adaptations during pregnancy in women with CKD and how these adaptations relate to perinatal outcomes. In this review, dietary and supplementation recommendations for CKD in adults and pregnant women are summarized from current clinical guidelines. We present the main nutrition care practices that have been studied in CKD pregnancies. This review will be helpful to health professionals as a preliminary reference for nutrition assessment and therapy in pregnant women with CKD.

Experience with a Large Dose (500 MG) of Intravenous Iron Dextran and Iron Saccharate in Peritoneal Dialysis Patients

Objective

To compare efficacy in anemia correction and side effects of large doses of intravenous (IV) iron dextran and iron saccharate preparations in peritoneal dialysis (PD) patients.

Setting

Tertiary-care teaching hospital of University of Toronto.

Design

Retrospective analysis of 379 PD patients who attended PD clinics in past 5 years. Of these 379 patients, 62 were selected to receive IV iron based on ferrokinetic markers of iron deficiency, noncompliance to or ineffectiveness of oral iron, or increased erythropoietin (EPO) requirement.

Intervention

Sixty-one patients received two IV iron injections of 500 mg each, 1 week apart, 33 patients received iron dextran, 23 received iron saccharate, and 5 received both iron dextran and iron saccharate. One patient developed anaphylaxis to a test dose of iron dextran and was excluded from further therapy. Blood samples were collected before and 3 and 6 months after iron infusions.

Results

At 3 months, the group's average hemoglobin rose from 98.3 ± 18.3 g/L to 110.6 ± 16.4 g/L ( p < 0.0001). Ferritin rose from 104.9 ± 115.4 μg/L to 391.5 ± 294.1 μg / L ( p < 0.0001), and iron saturation from 0.17 ± 0.07 to 0.26 ± 0.19 ( p < 0.0001). Erythropoietin requirements fell from 7278.7 IU/week to 5900 IU/week ( p < 0.01). Five of the 34 patients who received iron dextran developed minor side effects and 1 patient had anaphylaxis to the test dose. Of the 23 patients who received iron saccharate, 1 had an anaphylactic reaction and 2 had transient chest pain, which subsided without therapy. Overall, there were more side effects with iron dextran (7.4% of injections) compared to the iron saccharate group (4.3% of injections), but this difference was statistically insignificant. Although statistically insignificant, there was an increase in the number of peritonitis episodes during the 6 months after IV iron infusion, especially with iron dextran, compared to the peritonitis episodes during the 6 months before iron infusions.

Conclusion

Our study indicates that IV iron in PD patients is effective in restoring iron stores and in decreasing EPO requirements. One anaphylactic reaction occurred in each group. Our data suggest that as much caution be exercised with iron saccharate as with iron dextran. The slight trend toward increased peritonitis rates after iron infusions needs to be investigated in a larger group of patients.

Efficacy of a Low-Dose Intravenous Iron Sucrose Regimen in Peritoneal Dialysis Patients

Objective

Sufficient iron substitution leads to a decrease in the required recombinant human erythropoietin (rHuEPO) dose and/or an increased hematocrit in dialysis patients. Intravenous (IV) application of larger doses of iron sucrose may be associated with hyperferritinemia, appearance of catalytically free iron, and impaired phagocyte function. Therefore, we investigated the effectiveness of a low-dose IV iron regimen in peritoneal dialysis (PD) patients.

Patients and Interventions

Forty-five PD patients were followed over a period of 1 year. Serum ferritin, serum transferrin saturation, and hemoglobin were measured monthly. In cases of absolute iron deficiency (serum ferritin < 100 μg/L), 50 mg iron sucrose was given IV every second week. In cases of functional iron deficiency (ferritin ≥ 100 μg/L and transferrin saturation < 20%) and in iron repleted patients (ferritin ≥ 100 μg/L and transferrin saturation ≥ 20%), 50 mg IV iron sucrose was applied monthly. Iron therapy was stopped in cases of acute infection (until complete recovery) and when serum ferritin level was ≥ 600 μg/L.

Results

To analyze the influence of iron substitution on erythropoiesis and rHuEPO requirements, the EPO resistance index (ERI; quotient of rHuEPO dose in units/kilogram/week and hemoglobin in grams per deciliter) was calculated every 3 months. The ERI decreased significantly during the course of the study in the whole patient group ( p = 0.009) as well as in the subgroup of 21 patients with absolute iron deficiency ( p = 0.01). A nonsignificant decrease in the ERI was observed within the group of 14 iron repleted patients ( p = 0.5). There was no significant change in the ERI in 10 patients with functional iron deficiency ( p = 0.6).

Conclusion

The low-dose IV iron regimen used in this study substantially decreased rHuEPO requirements in patients with absolute iron deficiency and was effective in maintaining iron stores in iron repleted patients. However, in the absence of significant hyperparathyroidism, aluminum toxicity, or inadequate dialysis, it did not improve the ERI in patients with functional iron deficiency.

Sex-age-specific handgrip strength and mortality in an incident hemodialysis cohort: The risk explained by nutrition and comorbidities

OBJECTIVE:

To investigate associations of sex-age-specific handgrip strength by a dynamometer with all-cause mortality and the percent excess risk explained (%ERE) by comorbidities and nutritional indicators in incident maintenance hemodialysis patients.

METHODS:

Prospective cohort of 413 adult patients (165 women, 248 men, 299 <60 years and 114 ⩾60 years) with <6 months (82% <3 months) on dialysis enrolled in PROHEMO in Salvador, Brazil. Low and high handgrip strength groups were based on sex-age-specific cutoffs (17.8 kg for women <60 years, 13.8 kg for women ⩾60 years, 29.5 kg for men <60 years, and 21.9 kg for men ⩾60 years). We used Cox regression to estimate the mortality hazard ratio. The %ERE was determined by the equation (HR1 - HR2)/(HR1 - 1) × 100, in which HR1 represented the hazard ratio in a model with a smaller number of covariates and HR2 represented the hazard ratio in a subsequent model with the inclusion of new covariates plus the variables included in the previous model.

RESULTS:

The mortality hazard ratio comparing low and high handgrip strength was 2.58 (95% confidence interval: 1.73, 3.85) in the model with sociodemographic factors and vintage and 2.25 (95% confidence interval: 1.49, 3.43) with addition of comorbidities, corresponding to a %ERE of 21%. The hazard ratio was 1.98 (95% confidence interval: 1.29, 3.06) after addition of nutritional indicators corresponding to %ERE of 38%. Results stratified by age and gender followed similar patterns.

CONCLUSION:

These results provide support for the assessment of handgrip strength in all maintenance hemodialysis patients for early identification of those who may require special care to improve nutritional status and survival.

Iron sucrose: assessing the similarity between the originator drug and its intended copies

Iron sucrose (IS) is a complex nanocolloidal intravenous suspension used in the treatment of iron-deficiency anemia. Follow-on IS products (iron sucrose similars (ISSs)) have obtained marketing authorization by the generic pathway, implying that identical copies of IS may be manufactured. However, recent prospective and retrospective clinical studies showed discrepancies in clinical outcomes, which might be related to differences in physicochemical properties. The aim of this work is to measure and compare the physicochemical properties of IS and three ISSs available in the market using innovative analytical procedures. The comprehensive elucidation of size, size distribution, morphology, and stability of these complex drugs revealed very significant differences between the products. This study serves to provide the basis to define critical quality attributes that may be linked to differences in clinical outcome and thus may contribute to an adequate regulatory approach for IS and its follow-on products.

Integrating Clinical Nutrition Practice Guidelines in Chronic Kidney Disease

Chronic kidney disease (CKD) is a permanent, progressive loss of kidney function characterized by a decline in glomerular filtration rate (GFR). Early identification of CKD risk factors provides an opportunity to prevent or delay the progression of kidney disease and decrease morbidity and mortality. There is increasing evidence to suggest that the adverse outcomes of CKD can be delayed or prevented by early detection and treatment. Current literature suggests that a low-protein, low-phosphorus diet may retard the progression of kidney disease. Other modifiable risk factors affecting CKD include proteinuria, hypertension, hyperglycemia, dyslipidemia, bone disease, anemia, and obesity. This discussion will review the current clinical nutrition guidelines for managing adult patients with CKD.

Challenges of Providing Nutrition Support in the Outpatient Dialysis Setting

Malnutrition is prevalent in maintenance hemodialysis (MHD) patients and has been strongly associated with increased morbidity and mortality. There are numerous contributors to the development, occurrence, and persistence of malnutrition in the MHD patient. Intensive diet counseling and use of enteral supplements may not be effective interventions for patients exhibiting high nutrition risk. More aggressive nutrition options such as enteral and parenteral support are less often used and have associated risks. Intradialytic parenteral nutrition (IDPN) as a form of PN delivered during the dialysis procedure is a convenient and attractive convention that is underused because of its history and controversy. There is a lack of randomized controlled trials demonstrating improved morbidity and mortality with all nutrition support interventions in MHD patients. This research is particularly crucial for IDPN in order to render change in Medicare reimbursement. Qualification of patients for this therapy is difficult because of the very strict coverage criteria. For those patients who do qualify for IDPN, clinician nutrition support knowledge is essential for safe administration of solutions and effective physical, metabolic, and nutrition management of the patient. Attention to other factors that contribute to malnutrition in MHD such as treatment adequacy and comorbid conditions is important; however, the early detection of malnutrition in the MHD patient with appropriate level of nutrition intervention is critical. Future improved understanding of the malnutrition of uremia will allow for development and investigation of other strategies that are anti-catabolic or anabolic.

Protein and Energy Depletion in Chronic Hemodialysis Patients: Clinical Applicability of Diagnostic Tools

Protein and energy depletion states are common and associated with increased morbidity and mortality in chronic hemodialysis (CHD) patients. Therefore, proper use of diagnostic tools to assess depleted states in CHD patients is critical. Assessment of protein and energy status can be done by an array of methodologies that include simple estimates of the visceral and somatic pools of protein to more refined techniques to measure protein and energy balance. The nutritional and metabolic derangements in the CHD population are highly complex and can be confounded by multiple comorbidities and fluid shifts between body compartments. Therefore, assessment of protein and energy status in CHD patients requires a wide range of methodologies that not only identify depleted states but also monitor nutrition therapy and predict clinical outcome. Most important, these methods require cautious and individualized interpretation in order to minimize the interference of comorbid conditions frequently observed in the CHD population. Currently, there is not a single method that can be considered the gold standard for assessment of protein and energy status in CHD patients. Therefore, a combination of methods is recommended. In this review, we describe available methods to assess protein and energy status, with special considerations pertaining to CHD patients.

Carnitine Treatment Improved Quality-of-Life Measure in a Sample of Midwestern Hemodialysis Patients

BACKGROUND

Previously, we demonstrated that selected groups of hemodialysis patients might be more likely to have abnormalities of carnitine metabolism. The purpose of the present study was to examine the effects of carnitine therapy in these selected groups of hemodialysis patients on quality-of-life measures and erythropoietin dose.

METHODS

This was a double-blind, randomized, controlled trial, in which 50 hemodialysis patients were treated with either 2 g i.v. carnitine or placebo. The treatment period was for 24 weeks.

RESULTS

Thirty-four patients (15 in the treatment group) completed the study. The mean age was 69 +/- 15 years, 35% were women, and 44% had diabetes. Mean initial plasma total, free, short-chain acyl and long-chain acyl carnitine concentrations (micromol/L; mean +/- SEM) were 35.9 +/- 1.8, 18.2 +/- 1.1, 11.6 +/- 0.6, and 6.0 +/- 0.3, whereas the plasma acyl-to-free-carnitine ratio was 1.02 +/- 0.05. With respect to the Medical Outcomes Short Form-36 (SF-36), improvements from baseline were noted in the treatment group (n = 13) for role-physical (33.9 +/- 1.9 to 43.2 +/- 3.0, p < .05) and the SF-36 physical component summary score (36.1 +/- 2.7 to 39.7 +/- 2.3, p = .09) relative to changes in the control group (n = 14). The erythropoietin dose over the 24-week period was reduced from baseline in the treatment group relative to the placebo group (-1.62 +/- 0.91 vs 1.33 +/- 0.79 units erythropoietin/dry weight/hemoglobin concentration, respectively, p < .05).

CONCLUSIONS

After 24 weeks of i.v. carnitine therapy, SF-36 scores were improved and erythropoietin doses were reduced in hemodialysis patients, relative to the control group.

A Review of Ferric Pyrophosphate Citrate (Triferic) Use in Hemodialysis Patients

PURPOSE

The objective of this short review is to evaluate the efficacy of ferric pyrophosphate citrate and to determine its place in therapy based on the current published literature.

METHODS

A literature search was conducted and pared down to yield 4 placebo controlled Phase II and III clinically relevant trials.

FINDINGS

Ferric pyrophosphate citrate is a new intradialytic iron supplementation product that has been found to reduce the dose of erythropoiesis-stimulating agents and intravenous iron supplementation and to increase serum ferritin concentrations.

IMPLICATIONS

This agent may be administered to patients with stage 5 chronic kidney disease receiving hemodialysis as a new iron supplementation option to maintain hemoglobin, transferrin saturation, and ferritin concentrations.

Evaluation of Nutritional Status in Children during Predialysis, or Treated By Peritoneal Dialysis or Hemodialysis

OBJECTIVE

Malnutrition is one of the major causes of morbidity and mortality in children with chronic kidney disease (CKD). The objective of this study was to evaluate nutritional status of children with stage 3-4 CKD and treated by peritoneal dialysis or hemodialysis using anthropometric measurements, biochemical parameters and bioelectrical impedance analysis.

PATIENTS AND METHODS

The study included a total of 52 patients and 46 healthy children.

RESULTS

In anthropometric evaluation, the children with CKD had lower values for standard deviation score for weight, height, body mass index, skinfold thickness and mid-arm circumference than those of healthy children (p < 0.05). The fat mass (%) and the body cell mass (%) measurements performed by bioelectrical impedance analysis were lower compared with the control group (p < 0.05).

CONCLUSION

It is considered that bioelectrical impedance analysis measurement should be used with anthropometric measurements, which are easy to perform, to achieve more accurate nutritional evaluation in children.

Managing hyperphosphatemia in patients with chronic kidney disease on dialysis with ferric citrate: latest evidence and clinical usefulness

Ferric citrate is a novel phosphate binder that allows the simultaneous treatment of hyperphosphatemia and iron deficiency in patients being treated for end-stage renal disease with hemodialysis (HD). Multiple clinical trials in HD patients have uniformly and consistently demonstrated the efficacy of the drug in controlling hyperphosphatemia with a good safety profile, leading the US Food and Drug Administration in 2014 to approve its use for that indication. A concurrent beneficial effect, while using ferric citrate as a phosphate binder, is its salutary effect in HD patients with iron deficiency being treated with an erythropoietin-stimulating agent (ESA) in restoring iron that becomes available for reversing chronic kidney disease (CKD)-related anemia. Ferric citrate has also been shown in several studies to diminish the need for intravenous iron treatment and to reduce the requirement for ESA. Ferric citrate is thus a preferred phosphate binder that helps resolve CKD-related mineral bone disease and iron-deficiency anemia.

Utilization Patterns of IV Iron and Erythropoiesis Stimulating Agents in Anemic Chronic Kidney Disease Patients: A Multihospital Study

Intravenous (IV) iron and Erythropoiesis Stimulating Agents (ESAs) are recommended for anemia management in chronic kidney disease (CKD). This retrospective cohort study analyzed utilization patterns of IV iron and ESA in patients over 18 years of age admitted to University Health System Hospitals with a primary or secondary diagnosis of CKD between January 1, 2006 to December 31, 2008. A clustered binomial logistic regression using the GEE methodology was used to identify predictors of IV iron utilization. Only 8% (n = 6678) of CKD patients on ESA therapy received IV iron supplementation in university hospitals. Those receiving iron used significantly less amounts of ESAs. Patient demographics (age, race, primary payer), patient clinical conditions (admission status, severity of illness, dialysis status), and physician specialty were identified as predictors of IV iron use in CKD patients. Use of IV iron with ESAs was low despite recommendations from consensus guidelines. The low treatment rate of IV iron represents a gap in treatment practices and signals an opportunity for healthcare improvement in CKD anemic patients.

The importance of body composition and dry weight assessments in patients with chronic kidney disease

Chronic volume overload is the major cause of hypertension and other cardiovascular morbidity in dialysis patients. One of the most important goals of physicians who take care of patients with chronic renal failure is to obtain near euvolemia or "dry body weight" in order to maintain or normalize blood pressure and prevent further cardiovascular events. In clinical practice, exact estimation of dry weight in hemodialysis patients remains a major challenge. Alterations in body composition, particularly malnutrition, are common in patients receiving long-term hemodialysis and contribute to a high mortality rate. In contrast, obesity - a known risk factor for cardiovascular morbidity and mortality - is prevalent amongst kidney allograft recipients in - long term after renal transplantation. Several technological tools and biochemical markers for estimation of plasma volume and body composition are available for clinical use. Our aim was to highlight the importance of control of body fluid volume and body composition in patients with chronic kidney disease and to describe the different methods available for such measurements.

Obesity control and low protein diet preserve or even improve renal functions in Bardet-Biedl syndrome: a report of two cases

Background

Bardet-Biedl syndrome (BBS) is a rare autosomal-recessive disorder characterized by abdominal obesity, mental retardation, dysmorphic extremities, retinal dystrophy, hypogonadism, and kidney structural abnormalities or functional impairment. It is now considered a significant cause of chronic and end-stage renal disease in children. To the best of our knowledge there have been no previous studies on the role of diet in the management of renal functions in patients with BBS.

Case Reports

Two siblings, aged 32 and 27 years, with BBS are presented. On admission both patients were obese, with body mass indexes (BMI) of 40 and 39 kg/m². Their creatinine clearances (CrCl) were 41 and 24 mL/min. After 2 years of follow-up with a diet consisting of 0.6 g/kg/day protein and 1400 kcal/day energy, their BMI’s were decreased to 29 and 27 kg/m², whereas their CrCl’s were increased to 44 and 32 mL/min, respectively. ^99mTc-MAG3 scintigraphy also revealed improved renal function.

Conclusions

Since this syndrome most likely results in end-stage renal disease, follow-up of renal dysfunction is essential. Low protein diet and/or obesity control may slow the progression of renal failure in patients with BBS.

Assessment of body composition in peritoneal dialysis patients using bioelectrical impedance and dual-energy x-ray absorptiometry

INTRODUCTION

Protein energy wasting is closely related to increased morbidity and mortality in peritoneal dialysis (PD) patients. Simple reliable and easily available methods of determining nutritional status and recognition of short-term changes in body composition are therefore important for clinical practice.

METHODS

We compared whole-body and segmental composition using multifrequency bioelectrical impedance analysis (MF-BIA) and dual-energy X-ray absorptiometry (DEXA) in 104 stable PD patients.

RESULTS

Assessment of whole-body composition showed that lean body mass (LBM) was highly correlated with good method agreement using DEXA as the reference test (r = 0.95, p < 0.0001; bias -0.88 kg, 95% CI -1.53 to 0.23 kg). Similarly, high correlation and good method agreement were found for fat mass (r = 0.93, p < 0.0001; bias 0.69 kg, 95% CI 0.03-1.36 kg). Segmental analysis of LBM revealed strong correlations between LBM for trunk, left and right arms and legs (r = 0.90, 0.84, 0.86, 0.89 and 0.90, respectively, p < 0.0001). Bone mineral content derived by MF-BIA overestimated that measured by DEXA (bias 0.740 kg, 95% CI 0.66-0.82 kg).

CONCLUSION

MF-BIA may potentially be a useful tool for determining nutritional status in PD patients and serial estimations may help recognize short-term changes in body composition.

Consequences and therapy of the metabolic acidosis of chronic kidney disease

Metabolic acidosis is common in patients with chronic kidney disease (CKD), particularly once the glomerular filtration rate (GFR) falls below 25 ml/min/1.73 m(2). It is usually mild to moderate in magnitude with the serum bicarbonate concentration ([HCO(3)(-)]) ranging from 12 to 23 mEq/l. Even so, it can have substantial adverse effects, including development or exacerbation of bone disease, growth retardation in children, increased muscle degradation with muscle wasting, reduced albumin synthesis with a predisposition to hypoalbuminemia, resistance to the effects of insulin with impaired glucose tolerance, acceleration of the progression of CKD, stimulation of inflammation, and augmentation of β(2)-microglobulin production. Also, its presence is associated with increased mortality. The administration of base to patients prior to or after initiation of dialysis leads to improvement in many of these adverse effects. The present recommendation by the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKF KDOQI) is to raise serum [HCO(3)(-)] to ≥ 22 mEq/l, whereas Caring for Australians with Renal Impairment (CARI) recommends raising serum [HCO(3)(-)] to >22 mEq/l. Base administration can potentially contribute to volume overload and exacerbation of hypertension as well as to metastatic calcium precipitation in tissues. However, sodium retention is less when given as sodium bicarbonate and sodium chloride intake is concomitantly restricted. Results from various studies suggest that enhanced metastatic calcification is unlikely with the pH values achieved during conservative base administration, but the clinician should be careful not to raise serum [HCO(3)(-)] to values outside the normal range.

Safety issues with intravenous iron products in the management of anemia in chronic kidney disease

Anemia is a very common clinical problem in patients with chronic kidney disease (CKD) and is associated with increased morbidity and mortality in these patients. Erythropoietin is a hormone synthesized that is deficient in the majority of patients with advanced kidney disease, thereby predisposing these patients to anemia. The other cause of anemia is deficiency of iron. Iron deficiency anemia is common in people with CKD and its importance in supporting erythropoiesis is unquestioned, especially in those patients treated with erythropoietin. Intravenous iron is frequently used to treat anemia in CKD patients and is very efficacious in increasing hemoglobin but at the same time there are some safety issues associated with it. The objective of this review is to assess the frequency of adverse drug events associated with four different iron formulations: two iron dextran products known as high and low molecular weight iron dextran, iron sucrose, and sodium ferric gluconate complex. Several electronic databases were searched. In general, with the exception of high molecular weight iron dextran, serious or life-threatening adverse events appeared rare. Iron sucrose has the least reported adverse events and high molecular weight iron dextran has the highest number of reported adverse events. Low molecular weight iron dextran and ferric gluconate fall in between these two for number of adverse drug events.

Iron therapy for renal anemia: how much needed, how much harmful?

Iron deficiency is the most common cause of hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) in end-stage renal disease (ESRD) patients. Iron deficiency can easily be corrected by intravenous iron administration, which is more effective than oral iron supplementation, at least in adult patients with chronic kidney disease (CKD). Iron status can be monitored by different parameters such as ferritin, transferrin saturation, percentage of hypochromic red blood cells, and/or the reticulocyte hemoglobin content, but an increased erythropoietic response to iron supplementation is the most widely accepted reference standard of iron-deficient erythropoiesis. Parenteral iron therapy is not without acute and chronic adverse events. While provocative animal and in vitro studies suggest induction of inflammation, oxidative stress, and kidney damage by available parenteral iron preparations, several recent clinical studies showed the opposite effects as long as intravenous iron was adequately dosed. Thus, within the recommended international guidelines, parenteral iron administration is safe. Intravenous iron therapy should be withheld during acute infection but not during inflammation. The integration of ESA and intravenous iron therapy into anemia management allowed attainment of target hemoglobin values in the majority of pediatric and adult CKD and ESRD patients.

The New KDOQITM Clinical Practice Guidelines and Clinical Practice Recommendations for Diabetes and CKD

BACKGROUND/AIMS

The National Kidney Foundation (NKF) recently published new guidelines and clinical practice recommendations for the diagnosis and management of patients with diabetes and chronic kidney disease (CKD).

METHODS

Guidelines were developed using an evidence-based approach. When sufficient evidence was lacking, recommendations were developed that reflect expert opinion.

RESULTS

Guidelines describe the process for screening and diagnosis of kidney disease in the setting of diabetes and the management of hyperglycemia, hypertension, dyslipidemia, and nutrition. Recommendations describe the management of albuminuria in the normotensive diabetic patient and the potential value of albuminuria as a marker of treatment efficacy; the impact of diabetes and CKD in special populations; the importance of behavioral self-management; and the value of intensive multifaceted intervention in these high risk patients.

CONCLUSIONS

The new guidelines and recommendations update and extend the scope of the NKF's Kidney Disease Outcomes Quality Initiative (KDOQI(TM)).

Haemodialysis Fluid: Composition and Clinical Importance

Dialysis fluid is produced by the blending of treated water with electrolytes at the patients bed side. Its preparation and composition are important elements of treatment optimisation since many of the constituents play a role in patient well-being. Ideally the composition of the dialysis fluid should match that of plasma, but due to differences between patients, as well as the increasing number of elderly patients receiving treatment, have resulted in a move towards individualisation of the electrolyte and buffer composition to patient needs. Such individualisation is facilitated by the availability of technology, however it is not yet possible to individualise minor electrolytes, such as K(+), Ca(2+) and Mg(2+). Early dialysis treatments were frequently accompanied by pyrogen reactions arising from bacterial contamination of the dialysis fluid. Today the focus is on the stimulation of mononuclear cells by bacterial fragments contributing to chronic inflammation associated with long-term haemodialysis therapy, and which has led to suggestions regarding the desirability of using ultra-pure dialysis fluid to prevent or to delay complications associated with their presence.

Selected pharmacokinetic issues in patients with chronic kidney disease

Pharmacotherapy plays an important role in the care of a chronic kidney disease (CKD) patient but delivering this therapy can be challenging. Besides alterations in the pharmacokinetic parameters of absorption, distribution, metabolism and elimination, the average CKD patient must take multiple medications each day. The likelihood of an adverse drug reaction increases with each medication added to these patients' daily regimen. In this article we discuss selected pharmacokinetic issues unique to CKD patients.

Does hepcidin affect erythropoiesis in hemodialysis patients?

INTRODUCTION

Prohepcidin is the precursor of hepcidin, a liver-derived peptide involved in iron metabolism by blocking its intestinal absorption and its release by the reticuloendothelial system. Iron overload and inflammation increase hepcidin expression, whereas anemia and hypoxia suppress it. In the present study prohepcidin levels were determined in the serum of hemodialysis (HD) patients and its correlations with iron metabolism markers, C-reactive protein (CRP) and hematocrit (Hct) were assessed.

PATIENTS AND METHODS

Forty-sixHD patients and 22 healthy volunteers were enrolled in the study. Hct, serum prohepcidin, CRP, iron, ferritin, transferrin saturation and transferrin receptors were measured. The weekly erythropoietin dose, last-month intravenous iron dose and the patients' demographics were recorded.

RESULTS

In comparison to the healthy volunteers, the HD patients had higher serum ferritin, transferrin receptors and CRP, lower serum iron and similar transferrin saturation and prohepcidin levels. In the patient group prohepcidin levels were negatively correlated with Hct but not with any other of the examined parameters. Multiple linear regression analysis considering age, inflammation, iron adequacy, erythropoietin dose and prohepcidin levels revealed that prohepcidin was the predominant determinant of Hct.

CONCLUSIONS

Taking into account the low Hct levels in the HD patients of our study, it seems plausible that the prohepcidin levels assessed in this group are inappropriately high. These functionally high prohepcidin levels may be associated with the factors that inhibit erythropoiesis in HD patients. On the other hand, the absence of other expected correlations indicates that further studies are needed in order to definitely clarify this aspect.

The effect of intravenous iron on oxidative stress in hemodialysis patients at various levels of vitamin C

BACKGROUND/AIMS

Vitamin C levels decrease during hemodialysis (HD), which deteriorates antioxidant defense. Vitamin C may also act pro-oxidatively, via reduction in Fe(III). We sought to determine whether intravenous iron (Fe(iv))-induced oxidative stress differs in HD patients with low and physiological vitamin C levels and whether intravenous vitamin C (C(iv)) administration during HD would change the response to Fe(iv).

PATIENTS AND METHODS

Twenty patients with vitamin C deficiency (median 15.7 micromol/l, range 8.0-22.7) received Fe(iv) (100 mg iron sucrose between 150 and 180 min of HD). After 4 weeks of oral supplementation, the levels of vitamin C were comparable with those of controls (60.1 micromol/l, range 47.4-70.9). Patients were subsequently treated with (1) Fe(iv), (2) Fe(iv) and continuous 2 mg/min C(iv) throughout HD, (3) saline (S), and (4) S+C(iv). Plasma thiobarbituric acid reacting substances (TBARS) and vitamin C were assessed before, during and after FE(iv)(S), and 15, 30 and 60 min after infusion.

RESULTS

Fe(iv) induced a comparable rise in TBARS in patients with vitamin C deficiency (before Fe(iv), 1.9 micromol/l, range 1.4-1.9; after Fe(iv), 2.6 micromol/l, range 2.3-2.9; p < 0.01) and in those with normal vitamin C (before Fe(iv), 1.9 micromol/l, range 1.7-2.1; after Fe(iv), 2.6 micromol/l, range 2.5-2.9; p < 0.01). Fe(iv)+C(iv) resulted in a greater increase in TBARS (after Fe(iv), 3.1 micromol/l, range 2.8-3.2) compared with Fe(iv) (p < 0.01).

CONCLUSION

Iron sucrose-induced oxidative stress is comparable in HD patients with vitamin C deficiency and in those with normal vitamin C. We documented a pro-oxidative effect of vitamin C during Fe(iv)+C(iv) administration.

Weekly low-dose treatment with intravenous iron sucrose maintains iron status and decreases epoetin requirement in iron-replete haemodialysis patients

BACKGROUND

Haemodialysis patients need sustained treatment with intravenous iron because iron deficiency limits the efficacy of recombinant human epoetin therapy in these patients. However, the optimal intravenous iron maintenance dose has not been established yet.

METHODS

We performed a prospective multicentre clinical trial in iron-replete haemodialysis patients to evaluate the efficacy of weekly low-dose (50 mg) intravenous iron sucrose administration for 6 months to maintain the iron status, and to examine the effect on epoetin dosage needed to maintain stable haemoglobin values in these patients. Fifty patients were enrolled in this prospective, open-label, single arm, phase IV study.

RESULTS

Forty-two patients (84%) completed the study. After 6 months of intravenous iron sucrose treatment, the mean ferritin value showed a tendency to increase slightly from 405 +/- 159 at baseline to 490 +/- 275 microg/l at the end of the study, but iron, transferrin levels and transferrin saturation did not change. The haemoglobin level remained stable (12 +/- 1.1 at baseline and 12.1 +/- 1.5 g/dl at the end of the study). The mean dose of darbepoetin alfa could be reduced from 0.75 to 0.46 microg/kg/week; epoetin alfa was decreased from 101 to 74 IU/kg/week; and the mean dose of epoetin beta could be reduced from 148 to 131 IU/kg/week at the end of treatment.

CONCLUSIONS

A regular 50 mg weekly dosing schedule of iron sucrose maintains stable iron stores and haemoglobin levels in haemodialysed patients and allows considerable dose reductions for epoetins. Low-dose intravenous iron therapy may represent an optimal approach to treat the continuous loss of iron in dialysis patients.

Benchmarking iron dextran sensitivity: reactions requiring resuscitative medication in incident and prevalent patients

BACKGROUND

Reliable information on the incidence of severe reactions to iron dextran is limited. Administration of agents of resuscitation in acute anaphylaxis may serve as a marker to quantify life-threatening adverse drug reactions.

METHODS

To determine the incidence of the most serious reactions to intravenous (i.v.) iron dextran, we searched the Gambro Healthcare US medical database for evidence of same-day administration of both i.v. iron dextran and parenteral adrenaline, corticosteroids or antihistamines. We confirmed each case as an iron dextran sensitivity reaction by direct inquiry. We also determined the total reported number of suspected adverse iron dextran reactions.

RESULTS

During the 16 month study period, we determined that 1,066,099 doses of i.v. iron dextran were given to 48,509 patients, including 20,213 patients who had not previously received iron dextran (iron dextran naïve). We identified seven patients who experienced reactions requiring resuscitative agents, all in response to a test dose (five patients) or first therapeutic dose (two patients), and therefore all in the iron-naïve (incident) group. Thus, we found the incidence of iron dextran reactions requiring resuscitative agents to be 0.035% (7 out of 20,213). No reaction was fatal. In a combined group of incident and prevalent patients, we found 337 total reports of suspected adverse reactions to iron dextran, without regard to severity of reaction, yielding an overall per patient adverse drug event (ADE) rate of 0.69% (337 out of 48,509) and per exposure rate of 0.03% (337 out of 1,066,099).

CONCLUSIONS

The incidence of reactions to iron dextran requiring resuscitative medications, per exposure or per patient, is approximately 0.035%. Reactions of this severity occur after either the test dose or first dose of iron dextran.

Intravenous iron in a primary-care clinic

The preferable route of iron delivery for most iron-deficient patients is oral. Parenteral iron therapy is used in patients who cannot tolerate oral iron or in cases in which oral iron is not sufficiently effective. The most frequent indications for parenteral iron therapy are unbearable gastrointestinal side effects induced by oral iron itself, worsening of inflammatory bowel disease symptoms, insufficient intestinal absorption, renal failure-caused anemia that is treated with erythropoietin, and unresolved ongoing bleeding, which would cause the acceptable oral doses of iron therapy to be exceeded. The serious adverse effects of iron dextran that was used in the past could explain the reluctance of medical personnel to prescribe this effective treatment. Patients with iron deficiency anemia were treated with intravenous iron in a primary care clinic. The iron gluconate was given in a dosage of 62.5 mg diluted in 150 mL of normal saline and was infused intravenously over 30 min, while iron sucrose was given in a dosage of 100 mg diluted in the same volume of normal saline and given at the same rate. In total, 724 infusions were administered to 57 patients. Iron sucrose was used in 628 infusions, and iron gluconate was used in the remaining 96. The frequency of the infusion treatments depended on the underlying disease and ranged from three times a week to once a month. Adverse effects were seldom observed and were minor in patients receiving iron gluconate, and were not registered at all in patients treated with iron sucrose. Two cases of flushing with paresthesias occurred. Slowing the infusion rate successfully eliminated these side effects. One case of hypotension was treated successfully with 500 cc of normal saline infusion. One case of dropout occurred, due to the patient's refusal to cooperate. No anaphylactic reactions were observed. Iron gluconate and iron sucrose are effective and safe for use in primary care clinics. The risk of adverse effects is low.

Parenteral iron therapy in treatment of anemia in end-stage renal disease patients: a comparative study between iron saccharate and gluconate

BACKGROUND

Anemia in hemodialysis patients is a complex syndrome. The impetus of this study was to assess the safety and efficacy of iron saccharate complex (ISC) and sodium ferric gluconate complex (SFGC) in treating anemia in hemodialysis patients.

METHODS

Forty-eight adult anemic patients of both genders (33 males and 15 females) who had an adequate level of both hemodialysis and nutrition status and received neither EPO nor parenteral iron therapy during the preceding 6 months were randomized to 2 groups. The first group comprised 22 patients who were treated with parenteral ISC, 100 mg twice weekly for 2 months and once weekly thereafter. The second group included 26 patients who received SFGC, 62.5 mg twice weekly for 2 months and once weekly thereafter. The patients were followed up for 6 months.

RESULTS

This head-to-head study showed that iron stores were adequately repleted by the use of both drugs. Repletion of iron stores was associated with a significant rise in both hemoglobin and hematocrit in both groups at the end of the follow-up period in comparison to their initial values at the start of the study (p < 0.001). Both parenteral iron therapy preparations were tolerated without a statistical difference between both groups.

CONCLUSION

This head-to-head study confirmed that both parenteral iron preparations are effective for adequate repletion of iron stores and constituted a step forward in the management of anemic hemodialysis patients without noticeable adverse effects related to the administration of both iron preparations.

Iron sucrose in hemodialysis patients: safety of replacement and maintenance regimens

BACKGROUND

Parenteral iron replacement and maintenance are frequently required in hemodialysis patients. However, serious adverse events have been reported after single doses of some intravenous iron products. This multicenter phase IV clinical trial examined the safety of iron sucrose for the treatment of iron deficiency and for the maintenance of iron sufficiency in hemodialysis patients.

METHODS

In this safety study, iron sucrose was given in two dosing regimens. Iron deficient patients were treated with intravenous iron sucrose, 100 mg, during 10 consecutive hemodialysis sessions (replacement regimen). Iron replete patients were given iron sucrose, 100 mg intravenous (iv) over 5 minutes, weekly for 10 weeks (maintenance regimen). At the end of each 10-dose cycle, iron status was reassessed, and dosing during the subsequent cycle was based on the adequacy of iron stores as per Dialysis Outcome Quality Initiative (K/DOQI) Guidelines. With each dosing regimen, adverse events, if any, were recorded and described.

RESULTS

Six hundred and sixty-five hemodialysis patients, including 80 who had experienced previous intolerance to other parenteral iron preparations, received a total of 8583 doses of iron sucrose. One hundred eighty-eight patients received more than one iv iron cycle (replacement, maintenance, or both). There were no serious or life-threatening drug-related adverse events.

CONCLUSION

Iron sucrose is safe when given as treatment for iron deficiency or for maintenance of iron stores.

The effects of iron dextran on the oxidative stress in cardiovascular tissues of rats with chronic renal failure

BACKGROUND

Redox-active iron can promote oxidative stress and tissue injury by catalyzing hydroxyl radical generation and lipid peroxidation. Intravenous iron preparations are routinely administered in conjunction with erythropoietin to treat anemia in patients with chronic renal failure (CRF), a condition that is marked by oxidative stress and inflammation. This treatment frequently elevates iron burden, which can potentially intensify oxidative stress and, thus, cardiovascular disease in this population.

METHODS

We studied renal function and oxidative stress parameters in the cardiovascular tissues of CRF (5/6 nephrectomized) and sham-operated control rats 3 months after a single intravenous infusion of iron dextran (500 mg/kg).

RESULTS

Arterial pressure was equally elevated and creatinine clearance was equally reduced in both iron-treated and -untreated CRF groups. Iron administration significantly raised the blood hemoglobin, serum iron concentration, and transferrin saturation in both CRF and control groups. Iron administration resulted in a significant rise in plasma concentration of lipid peroxidation product, malondialdehyde in the CRF rats, and an insignificant rise in the control group. Plasma oxidized low-density lipoprotein (LDL) concentration was increased in the CRF groups, and was not affected by iron administrations. Iron administration raised nitrotyrosine abundance in the aorta of CRF but not in the control group. Left ventricular tissue abundance of p22(phox) subunit of NAD(P)H oxidase was elevated in CRF group and was not affected, whereas p67(phox) subunit abundance was raised by prior iron administration. Iron administration insignificantly lowered aorta p22(phox), but had no effect on p67(phox) subunit abundance in the treated CRF group. Previous iron administration significantly lowered superoxide dismutase and catalase abundance in the aorta and glutathione peroxidase in the left ventricle of CRF animals, but did not significantly change these parameters in the iron-treated control animals.

CONCLUSION

A single intravenous injection of iron dextran increased oxidative stress in the cardiovascular tissues in the CRF group, but not the control rats, pointing to heightened susceptibility to iron-mediated toxicity in CRF. However, administration of iron dextran did not adversely affect kidney function, and favorably affected hemoglobin concentration in rats with CRF induced by renal mass reduction. Further studies are needed to explore the effects of other parenteral iron preparations, repeated intravenous iron administration, and presence of comorbid conditions such as diabetes.

Determination of iron sucrose (Venofer) or iron dextran (DexFerrum) removal by hemodialysis: an in-vitro study

Background

Intravenous iron is typically administered during the hemodialysis (HD) procedure. HD patients may be prescribed high-flux (HF) or high-efficiency (HE) dialysis membranes. The extent of iron sucrose and iron dextran removal by HD using HF or HE membranes and by ultrafiltration rate (UFR) is unknown.

Methods

Two in vitro HD systems were designed and constructed to determine the dialyzabiltiy of iron from a simulated blood system (SBS) containing 100 mg iron sucrose or iron dextran (system A) or 1000 mg iron sucrose (system B). Both in vitro systems utilized a 6-L closed-loop SBS system that was subject to 4 different HD conditions conducted over 4 hours: HE membrane + 0 ml/hr UFR; HE membrane + 500 ml/hr UFR; HF membrane + 0 ml/hr UFR; HF membrane + 500 ml/hr UFR. Blood flow and dialysate flow rates were 500 ml/min and 800 ml/min, respectively. The dialysate compartment was a 192-L open system for system A and a 6-L closed-loop system for system B. Samples from the SBS and dialysate compartments were taken at various time points and iron elimination rate and HD clearance was determined. Iron removal from the SBS > 15% was considered clinically significant.

Results

The greatest percentage removal from the SBS was 13.5% and -0.03% utilizing system A and B, respectively. Iron sucrose and iron dextran dialysate concentration was below the lower limits of assay (< 2 ppm) for system A. Dialysate recovery of iron was negligible: 0 – 5.4 mg system A and 5.47 – 23.59 mg for system B. Dialyzer type or UFR did not affect iron removal.

Conclusion

HF or HE dialysis membranes do not remove clinically significant amounts of iron sucrose or dextran formulations over a 4-hour HD session. This effect remained constant even controlling for UFR up to 500 ml/hour. Therefore, iron sucrose and iron dextran are not dialyzed by HE or HF dialysis membranes irrespective of UFR.

Advances in Anemia Management in Chronic Kidney Disease

The prevalence of chronic kidney disease (CKD) is increasing in the United States. Efforts to promote earlier intervention to screen for CKD and manage secondary complications are of paramount importance to improve overall care of this population. Anemia is a secondary complication of CKD that develops as kidney function declines. Historically, anemia management efforts have been primarily emphasized in patients with end-stage renal disease; however, early detection and treatment of anemia in the early stages of the disease are essential to prevent negative consequences of anemia such as reduced quality of life, left ventricular hypertrophy and mortality. With the increased prevalence of CKD and efforts focused on identifying this disorder early in its course, it is likely that more pharmacists will be involved in the management of CKD and secondary complications such as anemia. Treatment approaches must also be based on the more recently advocated guidelines from the National Kidney Foundation’s Kidney Disease Outcomes Quality Initiative (NKF-K/DOQI). This article reviews therapeutic issues of anemia of CKD, new agents for management, and the NKF-K/DOQI anemia management guidelines from a clinical perspective that will assist pharmacists involved in the care of these patients.

Iron sucrose: the oldest iron therapy becomes new

Several parenteral iron preparations are now available. This article focuses on iron sucrose, a hematinic, used more widely than any other for more than five decades, chiefly in Europe and now available in North America. Iron sucrose has an average molecular weight of 34 to 60 kd, and after intravenous (IV) administration, it distributes into a volume equal to that of plasma, with a terminal half-life of 5 to 6 hours. Transferrin and ferritin levels can be measured reliably 48 hours after IV administration of this agent. Iron sucrose carries no "black-box" warning, and a test dose is not required before it is administered. Doses of 100 mg can be administered over several minutes, and larger doses up to 300 mg can be administered within 60 minutes. The efficacy of iron sucrose has been shown in patients with chronic kidney disease (CKD) both before and after the initiation of dialysis therapy. Iron sucrose, like iron gluconate, has been associated with a markedly lower incidence of life-threatening anaphylactoid reactions and may be administered safely to those with previously documented intolerance to iron dextran or iron gluconate. Nonanaphylactoid reactions, including non-life-threatening hypotension, nausea, and exanthema, also are extremely uncommon with iron sucrose. Management of patients with the anemia of CKD mandates that we carefully examine the effectiveness and safety of this oldest of iron preparations and the accumulating present-day data regarding it and contemporaneous agents.

Issues related to iron replacement in chronic kidney disease

Recent epidemiologic studies show that iron deficiency occurs in the vast majority of patients with chronic kidney disease (CKD). In patients with CKD, increased iron losses and, to a lesser extent, poor oral absorption, can lead to iron-deficiency anemia. Correction of iron-deficiency anemia is preferable by the oral route, however, data on oral iron use are limited in this population. In CKD patients, parenteral iron administered with recombinant human erythropoietin (rHuEpo), is the best potential option for the correction of anemia. Nondextran iron preparations are preferable because of a reduced incidence of serious adverse events. Parenteral iron in CKD patients may not be entirely innocuous and, although commonly used, have not received Food and Drug Administration approval for use in this patient population. Exposure to intravenous (IV) iron may lead to oxidative stress, renal injury, infection, cardiovascular disease, and osteomalacia. Studies are needed to confirm the existence and magnitude of these complications. The current data suggest that the overall risk-benefit ratio favors use of IV iron when compared with untreated or partially treated iron-deficiency anemia.

Safety and efficacy of sodium ferric gluconate complex in patients with chronic kidney disease

BACKGROUND

We hypothesized that intravenous iron will improve hemoglobin (Hgb) concentrations in anemic patients with chronic kidney disease (CKD), and the response would be greater if the underlying erythropoietin deficiency also was treated.

METHODS

Charts of 58 CKD veterans (glomerular filtration rate < 80 mL/min) administered at least 125 mg of sodium ferric gluconate complex in sucrose (SFGC) during a period of 1 year for the primary outcome of an increase in Hgb level by at least 0.5 g/dL were reviewed.

RESULTS

Mean Hgb level at baseline was 10.5 +/- 1.4 (SD) g/dL (105 +/- 14 g/L) in the 30 patients administered recombinant human erythropoietin (rHuEPO) plus SFGC and 10.1 +/- 1.3 g/dL (101 +/- 13 g/L) in the 28 patients administered SFGC alone (P = not significant). The primary event occurred in 83% of the rHuEPO-plus-SFGC group at 31 days compared with 60% at 62 days in the group administered SFGC alone (P = 0.037, Cox F test). In patients administered SFGC alone, mean maximal Hgb level was 11.4 +/- 0.9 g/dL (114 +/- 9 g/L) in contrast to 12.4 +/- 1.7 g/dL (124 +/- 17 g/L) in the combination group, which remained significantly different even after adjustment for biologically important covariates (P = 0.01, analysis of covariance). Of the 240 doses of SFGC administered for which infusion records were available, 237 doses were well tolerated; three hypotensive episodes occurred in 2 patients, which did not result in discontinuation of the drug in either case.

CONCLUSION

Correction of anemia with parenteral iron alone suggests a high prevalence of iron deficiency in patients with CKD. Treatment of concomitant iron deficiency with SFGC was well tolerated in patients with CKD and appears to optimize management of anemia.

Dyslipidemia in pediatric renal disease: epidemiology, pathophysiology, and management

Dyslipidemia increases the risk of cardiovascular events among individuals with renal disease, and there is a growing body of evidence that it hastens the progression of renal disease itself. Children with nephrotic syndrome or renal transplants have easily recognized hyperlipidemia. Among those with chronic renal insufficiency or end-stage renal disease, detection of dyslipidemia requires more careful analysis and knowledge of normal pediatric ranges. Disordered lipoprotein metabolism results from complex interactions among many factors, including the primary disease process, use of medications such as corticosteroids, the presence of malnutrition or obesity, and diet. The systematic treatment of dyslipidemia in children with chronic renal disease is controversial because conclusive data regarding the risks and benefits are lacking. Hepatic 3-methylglutaryl coenzyme A reductase inhibitors (statins), fibrates, plant stanols, bile acid-binding resins, and dietary manipulation are options for individualized treatment. Prospective investigations are required to guide clinical management.

Evaluation of intestinal iron absorption by indirect methods in patients on hemodialysis receiving oral iron and recombinant human erythropoietin

Intestinal iron absorption was evaluated in 40 patients on hemodialysis therapy treated over 4 months with 105 mg/d of oral iron and recombinant human erythropoietin (rHuEPO). The effect of iron stores, erythropoietic activity (EA), and route of rHuEPO administration on absorption was evaluated. Iron was administered after basal determinations had been made and was stopped 15 days before obtaining the final determinations. Intestinal iron absorption was calculated by summing the increase in hemoglobin (Hb) iron (iron used for the synthesis of new Hb) and variations in estimated tissue iron reserves (reserves at the end of the study minus basal reserves). Markers of EA included soluble transferrin receptors (sTfRs) and erythron transferrin uptake (ETU). Iron losses caused by dialysis or normal obligatory iron losses were not measured. Hb levels increased from 8.38 +/- 1.4 to 10.75 +/- 1.5 g/dL (P < 0.05). sTfR levels reached their maximum value at 45 days (3.22 +/- 0.84 mg/mL; P < 0.05), and ETU increased from 40 +/- 26 to 61 +/- 39 micromol/L whole blood/d (P = 0.007). Intestinal iron absorption was 238 mg (interquartile range [Q75 to Q25], 255) at 2 months and 348 mg (Q75 to Q25, 475) at 4 months (P =0.02) and correlated positively with hematocrit at the end of the study (r = 0.826; P = 0.0001). No relationship between iron absorption and basal serum ferritin level or EA markers was observed. Intestinal iron absorption was similar regardless of the route of rHuEPO administration. In conclusion, intestinal iron absorption from medicinal iron covers erythropoietic requirements and allows Hb levels to increase significantly. It is proportional to the degree of efficient erythropoiesis reached and independent of tissue iron stores present before treatment, markers of EA, and rHuEPO administration route.