Early prediction of response to intravenous iron supplementation by reticulocyte haemoglobin content and high-fluorescence reticulocyte count in haemodialysis patients

Reticulocyte hemoglobin content associated with the risk of iron deficiency anemia

Background/Objective

Reticulocyte hemoglobin content (MCHr) was recognized as a rapid and reliable marker for investigating iron deficiency (ID). We hypothesized that MCHr was associated with the risk of iron deficiency anemia in adults.

Methods

This is a dual-center case-control study. A total of 806 patients and healthy individuals were recruited from Ruijin Hospital and Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine between January 2021 and December 2021. The participants were categorized into iron deficiency anemia (IDA) group (n = 302), non-IDA group (n = 366), and healthy control group (n = 138). According to the MCHr level, the participants were divided into two groups, i.e. normal MCHr (≥25 pg) and decreased MCHr (<25 pg) group. Multivariate logistic regression analysis and adjusted subgroup analysis were conducted to estimate the relative risk between MCHr and IDA, with confounding factors including age, sex, hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), Hematocrit (HCT), serum iron (Fe), ferritin (Ferrit), and total iron binding capacity (TIBC).

Results

Compared with the non-IDA, the MCHr level with IDA decreased significantly. ROC curve analysis showed that MCHr had the largest area under the AUC curve. After comprehensive adjustment for confounding factors, individuals with normal level of MCHr exhibited a decreased risk of IDA (OR = 0.68 [0.60, 0.77], P < 0.01), while the risk of IDA was up to 5 times higher for those with decreased MCHr.

Conclusion

Our findings supported the hypothesis that MCHr was associated with the risk of IDA in adults and could serve as an indicator of IDA severity. MCHr holds clinical value as an auxiliary diagnostic indicator, providing valuable insights into whether invasive examinations are warranted in the assessment of IDA.

Reticulocyte Hemoglobin as a Screening Test for Iron Deficiency Anemia: A New Cut-Off

Introduction: Latent iron deficiency (LID), in which iron stores in the body are depleted without incidental anemia, poses a key diagnostic challenge. Reticulocyte hemoglobin content (Ret-Hb) is directly correlated with the functionally available iron for heme synthesis in erythroblasts. Consequently, Ret-Hb has been proposed as an efficient iron status marker. Aim: To assess the importance of Ret-Hb in detecting latent iron deficiency as well as its use in screening for iron deficiency anemia. Materials and Methods: A study involving 108 individuals was conducted at Najran University Hospital, 64 of whom had iron deficiency anemia (IDA) and 44 of whom had normal hemoglobin levels. All patients were subjected to complete blood count (CBC), reticulocyte percentage, Ret-Hb, serum iron, total iron binding capacity (TIBC), and serum ferritin measurements. Results: A significant decrease in Ret-Hb level was observed in IDA patients compared to non-anemic individuals, with a cut-off value of 21.2 pg (a value below which indicates IDA). Conclusion: The measurement of Ret-Hb, in addition to CBC parameters and indices, provides an accessible predictive marker for both iron deficiency (ID) and IDA. Lowering the Ret-Hb cut-off could better allow for its use as a screening parameter for IDA.

Diagnostic accuracy and clinical usefulness of erythrocyte creatine content to predict the improvement of anaemia in patients receiving maintenance haemodialysis

BACKGROUND

The improvement of anaemia over time by erythropoiesis stimulating agent (ESA) is associated with better survival in haemodialysis patients. We previously reported that erythrocyte creatine content, a marker of erythropoietic capacity, was a reliable marker to estimate the effectiveness of ESA. The aim of this study was to examine the accuracy and clinical usefulness of erythrocyte creatine content to predict the improvement of anaemia in haemodialysis patients.

METHODS

ESA dose was fixed 3 months prior to the enrollment and was maintained throughout the study period. Erythrocyte creatine content and haematologic indices were measured at baseline in 92 patients receiving maintenance haemodialysis. Haemoglobin was also measured 3 months after. Improvement of anaemia was defined as ≥ 0.8 g/dL change in haemoglobin from baseline to 3 months.

RESULTS

Erythrocyte creatine content was significantly higher in 32 patients with improvement of anaemia compared to 60 patients with no improvement of anaemia (2.47 ± 0.74 vs. 1.57 ± 0.49 μmol/gHb, P = 0.0001). When 9 variables (erythrocyte creatine content, ESA dose, reticulocyte, haptoglobin, haemoglobin at baseline, serum calcium, intact parathyroid hormone, transferrin saturation and serum ferritin) were used in the multivariate logistic regression analysis, erythrocyte creatine emerged as the most important variable associated with the improvement of anaemia (P = 0.0001). The optimal cut-off point of erythrocyte creatine content to detect the improvement of anaemia was 1.78 μmol/gHb (Area under the curve: 0.86). Sensitivity and specificity of erythrocyte creatine content to detect the improvement of anaemia were 90.6% and 83.3%.

CONCLUSION

Erythrocyte creatine content is a reliable marker to predict the improvement of anaemia 3 months ahead in patients receiving maintenance haemodialysis.

[Evaluation of serum iron as a predictor of a hemoglobin response to injectable iron treatment in chronic hemodialysis patients]

BACKGROUND

The detection and correction of iron deficiency are essential for the treatment of anemia in chronic hemodialysis patients. The aim of our study was to assess the ability of serum iron to predict hemoglobin response to intravenous iron supplementation in hemodialysis patients.

METHODS

It is a retrospective study in 91 hemodialysis patients during 2016 at Clermont-Ferrand University Hospital for whom intravenous iron supplementation had been started. A responder patient was defined as an increase in hemoglobin greater than or equal to 1 g/dL/month and/or a decrease in the dose of erythropoiesis stimulating agent after two months of iron supplementation.

RESULTS

In responding patients, serum iron was significantly lower (6.7 ± 2.7 μmol/L) compared to non-responding patients (8.9±2.9 μmol/L; P<0.001). The positive response to iron supplementation was significantly associated with low serum iron (odds ratio = 0.58 [0.42-0.81]; P=0.002) in a logistic regression model taking into account ferritin, transferrin saturation coefficient, dose variation monthly iron and erythropoiesis stimulating agent and the duration of dialysis. The area under the receiver operating characteristic curve of serum iron, ferritin and transferrin saturation coefficient to predict the response to iron supplementation were 0.72, 0.51 and 0.64, respectively (serum iron versus ferritin [P=0.006] and serum iron versus transferrin saturation coefficient [P=0.04]). The sensitivity for serum iron below 7.5 μmol/L was better than that for ferritin below 86 ng/mL (P<0.001) and the specificity for serum iron below 7.5 μmol/L was better than that for TSC less than 19% (P=0.02).

CONCLUSION

Serum iron below 7.5 μmol/L can predict the success of the response to iron supplementation in chronic hemodialysis patients.

The effect of reticulocyte hemoglobin content on the diagnosis of iron deficiency anemia: A meta-analysis study

Background

Iron deficiency anemia (IDA) is the most common type of anemia worldwide and has many adverse effects on life quality. This meta-analysis study aims to show that reticulocyte hemoglobin content (CHr) is more effective than routinely used parameters in the diagnosis of IDA.

Methods

Comprehensive and systematic research was done using international databases including PubMed, Web of Science, Cochrane Library, Science Direct, and Google Scholar, which contain all articles published on IDA until December 29, 2020. Seventeen articles were included in the meta-analysis.

Results

The analyses found the Cohen's deffect size (Standardized Mean Difference) values of the parameters. Accordingly, CHr is 2.84 (95% CI 2.36 to 3.31), mean corpus volume (MCV) is 2.46 (95% CI 1.97 to 2.95), ferritin is 2.37 (95% CI 1.63 to 3.11), and transferrin saturation (TSAT) is 3.76 (95% CI 2.14 to 5.38). To diagnose IDA, the sensitivity value of the CHr concentration was found as 83.5% (95% CI 76.1 to 89.8), specificity value to be 91.8% (95% CI 85.5 to 96.4), and mean cut-off value as 28.2 pg.

Conclusions

The results of our study reveal the findings that CHr is a better biomarker than MCV and ferritin used in determining IDA, and its efficacy is lower than TSAT. It is very important to use it routinely for the pre-diagnosis of IDA, which is very important for public health. The groups in the study are heterogeneous but contain bias. Therefore, meta-analyses of studies with less heterogeneity of CHr are needed.

Evaluation of recombinant human erythropoietin responsiveness by measuring erythrocyte creatine content in haemodialysis patients

Background

One of the main causes of anaemia in patients with end-stage renal disease is relative deficiency in erythropoietin production. Eythropoiesis stimulating agent (ESA), a potent haematopoietic growth factor, is used to treat anaemia in haemodialysis patients. The effect of ESA is usually assessed by haematological indices such as red blood cell count, haemoglobin concentration and haematocrit, but erythrocyte indices do not provide information of the rapid change in erythropoietic activity. As erythrocyte creatine directly assess erythropoiesis, the aim of this study was to evaluate the effect of ESA in haemodialysis patients by measuring the erythrocyte creatine content.

Methods

ESA dose was fixed 3 months prior to the enrollment and was maintained throughout the entire study period. Erythrocyte creatine was measured with haematologic indices in 83 haemodialysis patients. Haemoglobin was also measured 3 months after.

Results

ESA dose (152.4 ± 62.9 vs. 82.2 ± 45.5 units/kg/week, P = 0.0001) and erythrocyte creatine (2.07 ± 0.73 vs. 1.60 ± 0.41 μmol/gHb, p = 0.0003) were significantly higher in 27 patients with haemoglobin <10 g/dL compared to 56 patients with haemoglobin ≥10 g/dL. There was a fair correlation between ESA dose and the concentration of creatine in the erythrocytes (r = 0.55, P < 0.0001). Increase in haemoglobin (>0.1 g/dL) was observed in 37 patients, whereas haemoglobin did not increase in 46 patients. Erythrocyte creatine levels were significantly higher in those patients with an increase in haemoglobin compared to those without (2.04 ± 0.64 vs. 1.52 ± 0.39 μmol/gHb, p < 0.0001). When 8 variables (ESA dose, erythropoietin resistance index, C-reactive protein, intact parathyroid hormone, iron supplementation, presence of anaemia, erythrocyte creatine and reticulocyte) were used in the multivariate logistic analysis, erythrocyte creatine levels emerged as the most important variable associated with increase in haemoglobin (Chi-square = 6.19, P = 0.01).

Conclusion

Erythrocyte creatine, a useful marker of erythropoietic capacity, is a reliable marker to estimate ameliorative effectiveness of ESA in haemodialysis patients.

The Reticulocyte Hemoglobin Equivalent as a Screening Marker for Iron Deficiency and Iron Deficiency Anemia in Children

Background: Iron deficiency (ID) is one of the most common nutritional deficiencies in children worldwide and may result in iron deficiency anemia (IDA). The reticulocyte hemoglobin equivalent (Ret-He) provides information about the current availability of iron in erythropoiesis. This study aims to examine the validation of Ret-He as a screening marker for ID and IDA in children. Methods: Blood samples were retrospectively obtained from medical records. Anemia was defined according to the definition provided by the World Health Organization (WHO) for children. ID was defined by transferrin saturation (TSAT) < 20% and ferritin < 100 ng/mL. Children were classified into four groups: IDA, non-anemia iron deficiency (NAID), control and others. Results: Out of 970 children, 332 (34.2%) had NAID and 278 (28.7%) presented with IDA. Analysis revealed that Ret-He significantly correlates with ferritin (rho = 0.41; p < 0.001), TSAT (rho = 0.66; p < 0.001) and soluble transferrin receptor (sTfR) (rho = −0.72; p < 0.001). For ROC analysis, the area under the curve (AUC) was 0.771 for Ret-He detecting ID and 0.845 for detecting IDA. The cut-off value for Ret-He to diagnose ID was 33.5 pg (sensitivity 90.7%; specificity 35.8%) and 31.6 pg (sensitivity 90.6%; specificity 50.4%) to diagnose IDA. Conclusions: The present study demonstrates Ret-He to be a screening marker for ID and IDA in children. Furthermore, Ret-He can be used as a single screening parameter for ID and IDA in children without considering other iron parameters. Economically, the use of Ret-He is highly relevant, as it can save one blood tube per patient and additional costs.

Evaluation of Iron Status by Reticulocyte Haemoglobin Content (Chr) in Chronic Kidney Disease Patients on Haemodialysis and Erythropoietin

Diagnosing iron deficiency with currently available tests is difficult in patients with chronic kidney disease (CKD) due to the inflammatory state associated with uraemia. The aim of this study was to evaluate the importance of reticulocyte haemoglobin (CHr) as a diagnostic tool of iron deficiency and a predictor to intravenous iron therapy in a cohort of CKD patients on haemodialysis in Sri Lanka. This was a descriptive cross sectional study involving hundred (100) patients with CKD on regular haemodialysis and erythropoietin. Patients were categorised into groups depending on serum ferritin, transferrin saturation and reticulocyte haemoglobin (CHr). All patients with CHr < 29 pg were treated with a single dose of intravenous(IV) iron 500 mg. The CHr was measured 72 h after the IV iron treatment to assess the response. Within the population mean haemoglobin was 9.27 g/dL, mean serum ferritin was 243.5 ng/mL, mean transferrin saturation was 18.6% and mean CHr was 29.2 pg. Thirty three of the 100 patients (33%) were subjected to IV iron therapy and there was a significant increase of CHr 72 h after IV iron treatment (p < 0.001). As a diagnostic tool in iron deficiency in CKD patients on haemodialysis, CHr showed a sensitivity of 56%, specificity of 73% and positive predictive value of 84%. Reticulocyte haemoglobin (CHr) can be used as an early predictor of response to IV iron therapy. However, further evaluation is necessary to consider CHr as a diagnostic tool to detect iron deficiency in CKD patients on haemodialysis.

Anemia and iron deficiency in Crohn's disease

Introduction: Anemia is a common extraintestinal complication of Crohn's disease (CD) mainly caused by iron deficiency, that affects the quality of life in CD patients. Elucidation of the etiology and pathology of iron-deficiency anemia (IDA) and anemia of chronic diseases (ACD) has developed in recent years. Common biochemical parameters of iron status are insufficient for assessment of patients with anemia and CD. Thus, novel iron indices are required for accurate assessment in IDA patients with CD. Oral iron supplementation for IDA treatment is common and is associated with minor gastrointestinal side effects. Intravenous substitution improves safety profiles but may be not tolerable in some patients. Fortunately, additional therapies for anemia of active CD have emerged in recent years.Area covered: Here, we propose the review article on the link among anemia, iron deficiency, and Crohn's disease. We discuss the current diagnosis and therapy of anemia and iron deficiency in CD and propose the new directions for future research.Expert commentary: Exploring pathogeneses and treatments of anemia and iron deficiency in Crohn's disease will develop potential tools for early diagnosis and effective treatment of anemia in CD patients, and improve their life quality.

Reticulocyte hemoglobin content as a function of iron stores at 35-36 weeks post menstrual age in very premature infants

BACKGROUND

Premature infants are born with lower iron stores and are at risk for iron deficiency during early infancy. To prevent iron deficiency, premature infants are routinely supplemented with 2 mg/kg/day oral elemental iron. Reticulocyte hemoglobin content (RET-He), a measure of iron deficiency, has not been well evaluated prior to discharge in premature infants.

OBJECTIVES

Our objectives were to evaluate RET-He and its correlation with serum ferritin (SF), an index of iron stores, at 35-36 weeks postmenstrual age (PMA) in ≤32 weeks gestational age (GA) infants.

METHODS

We performed a prospective nested study involving 24-32 weeks GA infants who were receiving 2 mg/kg/day oral elemental iron with full enteral feedings at 35-36 weeks PMA. Infants with the following conditions were excluded: craniofacial malformation, chromosomal disorders, TORCH (toxoplasmosis, other infections, rubella, cytomegalovirus, and herpes simplex), culture-proven sepsis, C-reactive protein >5 mg/l within 10 days of iron status assessment, or erythropoietin therapy. SF and RET-He were measured at 35-36 weeks PMA using chemiluminescence immunoassay and Sysmex XN hematology analyzer, respectively. RET-He <27 pg was deemed indicative of iron deficiency.

RESULTS

Ninety-eight infants were studied, of which 21 infants had RET-He <27 pg. There was a positive correlation between RET-He and SF (coefficient 0.22, p = .03) that remained significant after controlling for GA (coefficient 0.21, p = .03) and frequency of prior erythrocyte transfusions (coefficient 0.21, p = .03). On stratified analysis, there was a positive correlation between SF and RET-He in females (N = 52, coefficient 0.23, p = .02), but not in males (N = 46, coefficient 0.05).

CONCLUSIONS

Most premature infants receiving 2 mg/kg/day oral elemental iron are iron replete for erythropoiesis at 35-36 weeks PMA. RET-He increases with an increase in iron stores, suggesting that additional iron supplementation prior to discharge to very premature infants with borderline low RET-He may help prevent iron deficiency during early infancy.

Evaluation of Iron Status in Patients of Chronic Kidney Disease - A Study to Assess the Best Indicators Including Serum Transferrin Receptor Assay

Anemia is an early complication of chronic kidney disease (CKD). The iron deficiency is an important contributor, more so in the Indian population. As routine standalone iron tests do not accurately reflect the actual status in the complex environment of CKD, there is a need to study better indicators. Serum iron, ferritin, total iron-binding capacity (TIBC), and serum transferrin receptor (sTfR) levels were estimated in 100 primary iron deficiency anemia (IDA) patients (controls-Group 1) and 68 newly diagnosed CKD cases. The CKD patients were divided into two groups: Serum ferritin <=100 μg/L (Group 2) and >100 μg/L (Group 3). The values of percentage saturation, log of ferritin (log_ferritin), and the ratio of sTfR to log ferritin (sTfR/log_f or sTfR index) were calculated. The CKD cases were further divided depending on ferritin cut-offs of 30, 50, 70, and 100 μg/L and statistically analyzed including ROC and AUC, to choose the best diagnostic parameter for accurate assessment of iron status in CKD cases. The mean serum ferritin was 11.34 μg/L, 28.70 μg/L, and 281.81 μg/L, and the mean sTfR was 2.34 μg/ml, 1.82 μg/ml, and 1.28 μg/ml in Groups 1, 2, and 3. Among all groups, the difference was found to be significant for serum iron, log_ferritin, and sTfR/log_f. The sTfR and sTfR/log_f showed good discrimination between IDA and Anemia of chronic disease in CKD cases, but sTfR/log_f gave the best discrimination at all cut-off levels of ferritin. At a ferritin cut-off of 50 μg/L, the sTfR/log_f value of 0.83 had a sensitivity of 93.5% and specificity of 95.45%, and at a ferritin cut-off 100 μg/L, the same value of 0.83 had a sensitivity of 95.5% and specificity of 86.5%. The ratio of sTfR/log_f is the best indicator for assessing iron status in CKD.

Measurement of iron status in chronic kidney disease

Anemia is a common complication of chronic kidney disease (CKD) in children, and dysregulation of iron homeostasis plays a central role in its pathogenesis. Optimizing iron status is a prerequisite for effective treatment of anemia. Insufficient iron can lead to inappropriate escalation of the erythropoiesis-stimulating agent (ESA) dose, which is associated with adverse outcomes. Excess iron supplementation also has negative sequelae including free radical tissue damage and increased risk of systemic infection. Notwithstanding the importance of optimizing bioavailable iron for erythropoiesis for children with advanced CKD, achieving this remains challenging for pediatric nephrologists due to the historical lack of practical and robust measures of iron status. In recent years, novel techniques have come to the fore to facilitate accurate and practical assessment of iron balance. These measures are the focus of this review, with emphasis on their relevance to the pediatric CKD population.

Markers of iron status in chronic kidney disease

Anemia is one of the main comorbidities related to chronic kidney disease (CKD). Until the advent of erythropoiesis stimulating agents (ESA), endogenous erythropoietin deficiency has been thought to be the main culprit of anemia in CKD patients. The use of ESAs has shed new light on the physiology of CKD anemia, where iron homeostasis plays an increasingly important role. Disorders of iron homeostasis occurring in CKD turn the anemia management in those patients into a complex multifactorial therapeutic task, where ESA and Iron dose must be properly balanced to achieve the desired outcome without exposing the patients to the risk of serious adverse events. This review covers diagnostic markers traditionally used for quantifying iron status in CKD patients, such as serum ferritin and transferrin saturation, new ones, such as reticulocyte hemoglobin content and percent hypochromic red cells (HRC), as well as experimental ones, such as hepcidin and soluble transferrin receptor (sTfR). Each marker is presented in terms of their diagnostic performance, followed by biological and analytical variability data. Advantages and disadvantages of each marker are briefly discussed. Although serum ferritin and transferrin saturation are easily available, they exhibit large biological variability and require caution when used for diagnosing iron status in CKD patients. Reticulocyte hemoglobin content and the percentage of HRC are more powerful, but their widespread use is hampered by the issue of sample stability in storage. sTfR and hepcidin show promise, but require further investigation as well as the development of standardized, low-cost assay platforms.

Comparison of reticulocyte hemoglobin equivalent with traditional markers of iron and erythropoiesis in pediatric dialysis

BACKGROUND

Anemia is a major complication for patients on chronic dialysis. Erythropoietin is effective if iron is available, however unnecessary iron supplementation results in iron overload. Reticulocyte hemoglobin equivalent (Ret-He) may be useful for assessing iron status.

METHODS

A national retrospective cohort study including all children on chronic dialysis in New Zealand between 2007 and 2013, pairing Ret-He with demographic information, anemia indices, and markers of iron status.

RESULTS

In 606 observations, we found a modest relationship between Ret-He and transferrin saturation (TSAT) (r = 0.34, p < 0.001) and a poor correlation between Ret-He and ferritin (r = 0.09, p = 0.04). There was a negative correlation between ferritin and hemoglobin (r = -0.14, p = 0.002), a weak positive correlation between TSAT and hemoglobin (r = 0.12, p = 0.007), and a modest positive correlation between Ret-He and hemoglobin (r = 0.22, p < 0.001). The diagnostic performance of Ret-He to detect absolute iron deficiency (cut-off value 28.9 pg, sensitivity 90 %, specificity 75 %, AUC 0.87) was good.

CONCLUSIONS

Ret-He is a more relevant marker of iron status than ferritin and TSAT. This supports prospectively testing Ret-He to distinguish between iron deficiency and suboptimal erythropoietin dosing as competing causes for anemia. Ferritin is an unhelpful biomarker of iron deficiency in this setting.

Evaluation of the hypochromic erythrocyte and reticulocyte hemoglobin content provided by the Sysmex XE-5000 analyzer in diagnosis of iron deficiency erythropoiesis

Background:

Iron deficiency represents the most frequent cause of anemia. To diagnose iron deficiency some biochemical tests such as serum ferritin and the transferring saturation percent (TSAT%) are usually used. Recently, some hematological parameters such as mean reticulocyte hemoglobin content (CHr or Ret-He) and percentage of hypochromic RBCs (Hypo% or %Hypo-He) were proposed as alternative to biochemical tests. In this study, the analytic performance and the diagnostic efficiency of these two parameters provided by Sysmex XE5000 analyzer on iron deficiency patients with or without anemia (IDA and ID, respectively) were evaluated.

Methods:

One hundred and sixty-four healthy adults, 58 with IDA, 21 with iron depleted stores (ID), 23 with β-thalassemia trait, and 24 with non iron deficiency anemia were selected. The gold standard used to define iron deficiency was the coexistence of serum ferritin below 15 μg/L (12 in women) and TSAT <16%.

Results:

For %Hypo-He, the best cut-off value for both IDA and ID is 0.9% while for Ret-He is 30.6 pg. For both parameters the performance was better to diagnose IDA (AUC, 0.96 and 0.98) than ID (AUC, 0.93 and 0.95). The Ret-He behavior was always slightly better than that of %Hypo-He.

Conclusions:

The use of these two parameters is useful to detect iron deficiency conditions if the hemoglobin synthesis has already been compromised.

How the Target Hemoglobin of Renal Anemia Should Be

Renal anemia is caused by the deficiency of endogenous erythropoietin (Epo) due to renal dysfunction. We think that it is possible to slow the progression of chronic kidney disease (CKD) in case we initiate Epo early in pre-dialysis patients, especially in the non-diabetic population. Erythropoiesis stimulating agent (ESA) treatments targeting mild anemia (10-12 g/dl) can decrease the risk of occurrence of cardiovascular disease (CVD) in patients with hypertension, diabetes mellitus and congestive heart failure. As the large randomized controlled trials such as Cardiovascular Risk Reduction by Early Anemia Treatment with Epoetin Beta, Correction of Hemoglobin and Outcomes in Renal Insufficiency and Trial to Reduce Cardiovascular Events with Aranesp Thearpy in the Western countries suggested, we do not recommend high doses of ESA to achieve the target hemoglobin (Hb) level. The target Hb of >13 g/dl might lead to increase in the risk of CVD although maintaining a high Hb of >12 g/dl without ESA is not harmful for CKD patients. It is desirable to determine the target Hb in dialysis patients depending on their ages. Renal anemia should be monitored constantly to start ESA and iron replacement therapy at an appropriate time, while avoiding their excess in order to minimize the occurrence of CVD and other complications. Taken all the international guidelines and our clinical experiences together, we should consider administration of ESA when the Hb level becomes <11 g/dl in pre-dialysis patients and <10 g/dl in dialysis patients.

Efficacy and Safety of Intravenous Ferric Carboxymaltose in Geriatric Inpatients at a German Tertiary University Teaching Hospital: A Retrospective Observational Cohort Study of Clinical Practice

Current iron supplementation practice in geriatric patients is erratic and lacks evidence-based recommendations. Despite potential benefits in this population, intravenous iron supplementation is often withheld due to concerns regarding pharmacy expense, perceived safety issues, and doubts regarding efficacy in elderly patients. This retrospective, observational cohort study aimed to evaluate the safety and efficacy of intravenous ferric carboxymaltose (FCM, Ferinject) in patients aged >75 years with iron deficiency anaemia (IDA). Within a twelve-month data extraction period, the charts of 405 hospitalised patients aged 65–101 years were retrospectively analysed for IDA, defined according to WHO criteria for anaemia (haemoglobin: <13.0 g/dL (m)/<12.0 g/dL (f)) in conjunction with transferrin saturation <20%. Of 128 IDA patients screened, 51 (39.8%) received intravenous iron. 38 patient charts were analysed. Mean cumulative dose of intravenous FCM was 784.4 ± 271.7 mg iron (1–3 infusions). 18 patients (47%) fulfilled treatment response criteria (≥1.0 g/dL increase in haemoglobin between baseline and hospital discharge). AEs were mild/moderate, most commonly transient increases of liver enzymes (n = 5/13.2%). AE incidence was comparable with that observed in patients <75 years. No serious AEs were observed. Ferric carboxymaltose was well tolerated and effective for correction of Hb levels and iron stores in this cohort of IDA patients aged over 75 years.

Using the hemoglobin content of reticulocytes (RET-He) to evaluate anemia in patients with cancer

OBJECTIVES

Evaluation of anemia, particularly iron deficiency, in patients with cancer is difficult. This study examined using the hemoglobin content of reticulocytes (RET-He) to rule out iron deficiency, as defined by serum iron studies (transferrin saturation <20%, serum iron <40 μg/dL, and ferritin <100 ng/mL), in an unselected cancer patient population.

METHODS

Patients were entered into the study based on the existence of concurrent laboratory test requests for CBC and serum iron studies.

RESULTS

Using a threshold of 32 pg/cell, RET-He ruled out iron deficiency with a negative predictive value (NPV) of 98.5% and 100%, respectively, in the study population (n = 209) and in a subpopulation of patients with low reticulocyte counts (n = 19). In comparison, the NPV of traditional CBC parameters (hemoglobin, <11 g/dL; mean corpuscular volume, <80 fL) was only 88.5%.

CONCLUSIONS

These results support the use of RET-He in the evaluation of iron deficiency in a cancer care setting.

Efficacy and safety of intravenous iron therapy for functional iron deficiency anemia in hemodialysis patients: a meta-analysis

BACKGROUND

Studies on benefits of intravenous iron therapy among hemodialysis patients with functional iron deficiency anemia have shown conflicting results. We conducted a meta-analysis to assess the efficacy and safety of intravenous iron in this subset of patients.

METHODS

We searched MEDLINE (through December 2012), the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov for single-arm studies and randomized controlled trials (RCT) that examined the effect of intravenous iron for functional iron deficiency anemia in hemodialysis patients on anemia parameters and markers of oxidative stress and inflammation. Studies of absolute iron deficiency were excluded. Random-effect model meta-analyses were used to compute changes in outcomes of interest.

RESULTS

We identified 34 studies (2,658 patients), representing 24 single-arm studies, and 10 parallel-arm RCT. In the analyses of the study arms, intravenous iron therapy resulted in a significant increase in hemoglobin, serum ferritin, transferrin saturation rate, serum iron, reticulocyte hemoglobin content as well as a significant decrease in the percentage of hypochromic erythrocytes and erythropoietin dose. There were significant increases in plasma malonyldialdehyde level and thiobarbituric acid-reactive substances, and a decrease in neutrophil respiratory burst. The analyses of the RCT revealed less robust net changes in these parameters, and there was no increased risk of adverse events including infections, cardiac events and mortality.

CONCLUSIONS

Intravenous iron therapy for functional iron deficiency anemia in hemodialysis patients improves anemia parameters but exerts some effects on markers of oxidative stress that are of unclear clinical significance. The long-term safety and efficacy of this treatment strategy requires further study.

The iron cycle in chronic kidney disease (CKD): from genetics and experimental models to CKD patients

Iron is essential for most living organisms but iron excess can be toxic. Cellular and systemic iron balance is therefore tightly controlled. Iron homeostasis is dysregulated in chronic kidney disease (CKD) and contributes to the anemia that is prevalent in this patient population. Iron supplementation is one cornerstone of anemia management in CKD patients, but has not been rigorously studied in large prospective randomized controlled trials. This review highlights important advances from genetic studies and animal models that have provided key insights into the molecular mechanisms governing iron homeostasis and its disturbance in CKD, and summarizes how these findings may yield advances in the care of this patient population.

Iron indices and survival in maintenance hemodialysis patients with and without polycystic kidney disease

BACKGROUND

Anemia is less prominent in patients with polycystic kidney disease (PKD). Such iron indices as ferritin and transferrin saturation (TSAT) values are used to guide management of anemia in individuals on maintenance hemodialysis (MHD). Optimal levels of correction of anemia and optimal levels of TSAT and ferritin are unclear in chronic kidney disease patients and have not been studied specifically in PKD.

METHODS

We studied 2969 MHD patients with and 128 054 patients without PKD from 580 outpatient hemodialysis facilities between July 2001 and June 2006. Using baseline, time-dependent and time-averaged values with unadjusted and multivariable adjusted analysis models, the survival predictabilities of TSAT and ferritin were studied.

RESULTS

PKD patients were 58 ± 13 years old and included 46% women, whereas non-PKD patients were 62 ± 15 years old and 45% women. In both PKD and non-PKD patients, a time-averaged TSAT between 30 and 40% was associated with the lowest mortality. Time-averaged ferritin between 100 and <800 ng/mL was associated with the lowest mortality in PKD patients, although this range was 500 to <800 ng/mL in non-PKD patients.

CONCLUSIONS

In MHD patients with and without PKD, there was a U-shaped relationship between the average TSAT and mortality, and a TSAT of 30-40% was associated with the best survival. However, an average ferritin of 100-800 ng/mL was associated with the best survival in PKD patients, whereas that of non-PKD patients was 500-800 ng/mL. Further studies in PKD and non-PKD patients are necessary to determine whether or not therapeutic attempts to keep TSAT and ferritin levels in these ranges will improve survival.

Clinical significance of reticulocyte hemoglobin content in the diagnosis of iron deficiency anemia

Objective: The aim of this study was to evaluate the clinical significance of reticulocyte hemoglobin content (CHr) in the diagnosis of iron deficiency anemia (IDA) and to compare it with other conventional iron parameters.

Materials and Methods: A total of 32 female patients with IDA (serum hemoglobin <120 g/L and serum ferritin <20 ng/ mL) and 18 female patients with iron deficiency (serum hemoglobin > 120 g/L and serum ferritin <20 ng/mL) were enrolled.

Results: CHr was 24.95±3.92 pg in female patients with IDA and 29.93±2.96 pg in female patients with iron deficiency. CHr showed a significant positive correlation with hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, serum iron, and transferrin saturation and a significant negative correlation with transferrin and total iron-binding capacity. The cut-off value of CHr for detecting IDA was 29 pg.

Conclusion: Our data demonstrate that CHr is a useful parameter that can be confidently used in the diagnosis of IDA, and a CHr cut-off value of 29 pg predicts IDA.

Conflict of interest:None declared.

Reticulocyte parameters: markers of early response to oral treatment in children with severe iron-deficiency anemia

The aim of the present study was to determine the effects of exclusive oral iron supplementation (iron sulphate 2 mg/kg/die) in asymptomatic children with severe iron-deficiency anemia [median hemoglobin (Hb) level before treatment 6.3 g/dL; range 4.5 to 7 g/dL] and to investigate the accuracy of Hb, reticulocyte hemoglobin content (CHr), and absolute reticulocyte count (ARC) as markers for monitoring early response to treatment. The increase in ARC and CHr was statistically significant at day +3. There was a significant association between suitable logarithmic functions of the percentage increase in CHr and ARC at day +3 and the fraction of required Hb increase compared with baseline to reach the mean reference value for age and sex at day +14. If these results are confirmed in a larger population, ARC and CHr could be considered affordable and widely available markers to detect early responders to oral iron therapy, and to switch unresponsive children to parenteral iron supplementation or transfusion.

Evidence for tissue iron overload in long-term hemodialysis patients and the impact of withdrawing parenteral iron

BACKGROUND/AIMS

Erythropoiesis in long-term hemodialyzed (LTH) patients is supported by erythropoietin (rHuEpo) and intravenous (IV) iron. This treatment may end up in iron overload (IO) in major organs. We studied such patients for the parameters of IO in the serum and in major organs.

METHODS

Patients were treated with rHuEpo (6-8 x 10(3) units × 1-3/wk) and IV 100 mg ferric saccharate.

RESULTS

Of 115 patients, 21 had serum ferritin (SF) > 1000 ng/mL. This group was further analyzed. Their SF and transferrin saturation (TSAT) were 2688 ± 1489 ng/mL and 54.2 ± 32.7%, respectively (vs. 125-360 ng/mL and 20-50% in normal controls). Serum hepcidin was 60.1 ± 29.5 nm (vs. 10.61 ± 6.44 nm in controls) (P < 0.001). Nineteen patients had increased malonyldialdehyde, a product of lipid peroxidation, indicating oxidative stress. T2* MRI disclosed in 19 of 21 patients moderate to severe IO in the liver and spleen, in three of eight patients in the pancreas, but in no patient in the heart. After stopping IV iron for a mean of 12 months, while continuing rHuEpo, the mean SF decreased in 11 patients to 1682 ng/mL and the mean TSAT decreased to 28%, whereas hemoglobin did not change indicating that tissue iron was utilized.

CONCLUSION

High SF correlates with IO in the liver and spleen, but not in the heart.

Diagnosing anemia in inflammatory bowel disease: beyond the established markers

The main types of anemia in inflammatory bowel disease (IBD) are iron deficiency anemia (IDA) and anemia of inflammatory etiology, or anemia of chronic disease (ACD). In the management of IBD patients with anemia it is essential for the physician to diagnose the type of anemia in order to decide in an evidence-based manner for the appropriate treatment. However, the assessment of iron status in IBD in many cases is rather difficult due to coexistent inflammation. For this assessment several indices and markers have been suggested. Ferritin, seems to play a central role in the definition and diagnosis of anemia in IBD and transferrin, transferrin saturation (Tsat), and soluble transferrin receptors are also valuable markers. All these biochemical markers have several limitations because they are not consistently reliable indices, since they are influenced by factors other than changes in iron balance. In this review, in addition to them, we discuss the newer alternative markers for iron status that may be useful when serum ferritin and Tsat are not sufficient. The iron metabolism regulators, hepcidin and prohepcidin, are still under investigation in IBD. Erythrocytes parameters like the red cell distribution width (RDW) and the percentage of hypochromic red cells as well as reticulocyte parameters such as hemoglobin concentration of reticulocytes, red blood cell size factor and reticulocyte distribution width could be useful markers for the evaluation of anemia in IBD.

Diagnosis of iron deficiency in patients undergoing hemodialysis

To diagnose iron deficiency in patients undergoing hemodialysis, the percentage of hypochromic RBCs (with cellular hemoglobin concentration <280 g/L [HYPO%]) and mean reticulocyte hemoglobin content (CHret) provided by the Siemens ADVIA 120 and 2120 analyzers (Siemens Diagnostic Solutions, Tarrytown, NY) were proposed as alternatives to biochemical tests. Sysmex, with its XE-5000 analyzer (Sysmex, Kobe, Japan), also proposed the percentage of erythrocytes with cellular hemoglobin content lower than 17 pg (%Hypo-He) and equivalent of the mean reticulocyte hemoglobin content (Ret-He) with similar clinical applications. Our aim was to verify the clinical usefulness of the biochemical and cellular parameters as predictors of iron deficiency in patients undergoing long-term hemodialysis. We studied 69 patients undergoing hemodialysis 3 times weekly. The baseline values of serum ferritin and percentage of transferrin saturation were poor predictors of iron responsiveness. Better ability was demonstrated by reticulocyte indices (area under the curve [AUC], 0.74 for CHret and 0.72 for Ret-He; best cutoff values, 31.2 and 30.6 pg, respectively) and erythrocyte parameters (AUC, 0.72 for HYPO% and 0.68 for %Hypo-He; best cutoff values, 5.8 and 2.7, respectively). The newly proposed Ret-He and %Hypo-He can provide clinicians with information equivalent to CHret and HYPO%.

Quality counts: new parameters in blood cell counting

Recently several parameters have been introduced to the complete blood count such as nucleated red blood cells, immature granulocytes; immature reticulocyte fraction, immature platelet fraction and red cell fragments as well as new parameters for detection of functional iron deficiency. Leucocyte positional parameters, which may diagnose specific diseases (e.g. differentiate between abnormal lymphocytes in leukaemia and viral conditions and may also detect malarial infection) are now available. At this time they are only used for research; however, generally such parameters later become reportable. One manufacturer's routine analyser allows measurement of cells by flow cytometry using monoclonal antibodies. Currently, there are no accredited external quality assessment schemes (EQAS) for these parameters. For a number of parameters, on some instruments, there is no internal quality control, which brings into question whether these parameters should be used for clinical decision making. Other more established parameters, such as mean platelet volume, red cell distribution width and the erythrocyte sedimentation rate do not have EQAS available. The UK National EQAS for General Haematology held a workshop earlier this year in 2008 to discuss these parameters. Participants were asked to provide a consensus opinion on which parameters are the most important for inclusion in future haematology EQAS.

Evaluation of reticulocyte haemoglobin content as marker of iron deficiency and predictor of response to intravenous iron in haemodialysis patients

Because serum ferritin and transferrin saturation (TS) have a limitation in estimating iron status in haemodialysis patients, the reticulocyte haemoglobin content (CHr) has been proposed as a new tool. We investigate the accuracy of CHr in comparison with conventional tests and the relationship between changes in CHr and haemoglobin levels after therapy. We selected 140 haemodialysis patients receiving rHuEPO and intravenous iron supplementation and measured their complete blood count, CHr and iron parameters. Iron deficiency was defined as a ferritin <100 microg/l and/or a TS <20%. Hb, CHr, ferritin and TS levels were determined 1 month after therapy. Fifty-three patients were iron deficient. CHr were distributed with 33.7 +/- 1.4 pg in the iron sufficient group and with 29.9 +/- 1.9 pg in the iron deficient group (P = 0.001). The cutoff value of CHr for detecting iron deficiency was <32.4 pg. In iron deficient patients, a significant correlation was found between CHr and TS. The change in CHr after therapy was significantly larger in iron-deficient patients, and a lower baseline CHr is associated with a greater haemoglobin change. CHr is useful in screening iron status in dialysis patients, and a CHr cut-off value of 32 pg is appropriate for the assessment of iron deficiency. Moreover, CHr may serve as a predictor of the response to anaemia treatment.

Reticulocyte hemoglobin content

Under normal conditions, reticulocytes are the youngest erythrocytes released from the bone marrow into circulating blood. They mature for 1-3 days within the bone marrow and circulate for 1-2 days before becoming mature erythrocytes. Measurement of cellular hemoglobin concentration has long been reported by automated hematology analyzers as one of the red blood cell indices. The reticulocyte hemoglobin content (CHr or Ret-He) provides an indirect measure of the functional iron available for new red blood cell production over the previous 3-4 days. Measurement of reticulocyte hemoglobin content in peripheral blood samples is useful for diagnosis of iron deficiency in adults (Mast et al., Blood 2002;99:1489-1491) and children (Brugnara et al., JAMA 1999;281:2225-2230; Ullrich et al., JAMA 2005;294:924-930; Bakr and Sarette, Eur J Pediatr 2006;165:442-445). It provides an early measure of the response to iron therapy increasing within 2-4 days of the initiation of intravenous iron therapy (Brugnara et al., Blood 1994;83:3100-3101). Sequential measurements of reticulocyte hemoglobin content in patients with iron deficiency anemia provide a rapid means for assessing the erythropoietic response to iron replacement therapy (Brugnara et al., Blood 1994;83:3100-3101). It is also an early indicator or iron-restricted erythropoiesis in patients receiving erythropoietin therapy (Fishbane et al., Kidney Int 1997;52:217-222; Fishbane et al., Kidney Int 2001;60:2406-2411; Mittman et al., Am J Kidney Dis 1997;30:912-922; Tsuchiya et al., Clin Nephrol 2003;59:115-123; Chuang et al., Nephrol Dial Transplant 2003;18:370-377). Thus, reticulocyte hemoglobin content is a recent addition to an expanding list of biomarkers that can be used to differentiate iron deficiency from other causes of anemia.

Parenteral iron with erythropoiesis-stimulating agents for chemotherapy-induced anemia

Purpose. To discuss the clinical issues we addressed in the development of our institutional guidelines regarding the assessment of iron stores for cancer- and treatment-related anemia and the administration of parenteral iron with erythropoiesis-stimulating agents (ESAs).

Data sources. Studies published from January 1995 to August 2007 were identified by computer searches of Medline and hand searching of bibliographies of the articles identified via the computer searches. The current clinical practice guidelines were identified by computer searches of the web sites for national professional organizations that represent health care professionals who treat patients with cancer.

Results of data analysis. Hematopoietic responses demonstrate that epoetin alfa and darbepoetin alfa provide similar outcomes for patients with chemotherapy-induced anemia (CIA); however, up to 50% of patients receiving these agents fail to adequately respond. Functional iron deficiency defined as a state of iron-restricted erythropoiesis is likely the primary contributor to the lack of response. Hematopoietic responses following ESA therapy with parenteral iron are substantially higher compared to response with no or oral iron.

Conclusions. Iron stores should be assessed in all patients with cancer- or treatment-related anemia and parenteral iron should be administered to patients receiving ESA therapy to improve hematopoietic response. A unique algorithm that summarizes our institutional guidelines to assess iron stores and administer parenteral iron with ESA therapy in patients with CIA is included. J Oncol Pharm Practice (2008) 14: 5—22.

Effectiveness of oral and intravenous iron therapy in haemodialysis patients

Anaemia is a common and serious complication in patients with end-stage renal disease. Iron therapy is crucial in managing anaemia and maintenance of haemodialysis (HD) patients. This study investigated the efficacy of both oral and intravenous (i.v.) therapies, and the possible factors deleteriously affecting patient response to iron therapy. Forty patients on maintenance HD from a single institution were enrolled in this 6-month retrospective study. Group I (n = 20) received i.v. two ampoules of atofen (ferric chloride hexahydrate 193.6 mg) per week for a total of 6 weeks (total dosage, 960 mg). Group II (n = 20) received oral ferrous sulphate S.C. Tab (ferrous sulphate 324 mg) one pill three times daily (total dosage, 63,000 mg). Patients whose haematocrit (Hct) level increased at minimum 3% within the period were classified as responders. Iron i.v. ferric chloride (960 mg) was more effective than oral ferrous sulphate (63,000 mg) in correcting anaemia in HD patients with iron deficiency. In group I, serum triglyceride (TG) levels were significantly lower in patients responding to i.v. iron therapy than in patients with no response. In group II, serum high-sensitive C-reactive protein (hs-CRP) level was significantly lower in patients responding to oral iron therapy than patients with no response. The i.v. ferric chloride is more effective than oral ferrous sulphate in treating anaemia in HD patients with iron deficiency. Serum hs-CRP and TG levels may be parameters for predicting hyporesponsiveness to oral and i.v. iron therapies, respectively.

Assessing iron status: beyond serum ferritin and transferrin saturation

The increasing prevalence of multiple comorbidities among anemic patients with chronic kidney disease has made the use of serum ferritin and transferrin saturation more challenging in diagnosing iron deficiency. Because serum ferritin is an acute-phase reactant and because the inflammatory state may inhibit the mobilization of iron from reticuloendothelial stores, the scenario of patients with serum ferritin >800 ng/ml, suggesting iron overload, and transferrin saturation <20%, suggesting iron deficiency, has become more common. This article revisits the basis for the Kidney Disease Outcomes Quality Initiative recommendations regarding the use of serum ferritin and transferrin saturation in guiding iron therapy, then explores some of the newer alternative markers for iron status that may be useful when serum ferritin and transferrin saturation are insufficient. These newer tests include reticulocyte hemoglobin content, percentage of hypochromic red cells, and soluble transferrin receptor, all of which have shown some promise in limited studies. Finally, the role of hepcidin, a hepatic polypeptide, in the pathophysiology of iron mobilization is reviewed briefly.

Iron homeostasis in chronic inflammation

Inflammation induced anemia and resistance to erythropoietin are common features in patients with chronic kidney disease (CKD). Elevated levels of cytokines and enhanced oxidative stress, conditions associated with inflammatory states, are implicated in the development of anemia. Accumulating evidence suggests that activation of cytokine cascade and the associated acute-phase response, as it often occurs in patients with CKD, divert iron from erythropoiesis to storage sites within the reticuloendothelial system leading to functional iron deficiency and subsequently to anemia or resistance to erythropoietin. Other processes have also been shown to be involved in the pathogenesis of anemia provoked by the activated immune system including an inhibition of erythroid progenitor proliferation and differentiation, a suppression of erythropoietin production and a blunted response to erythropoietin. The present review concerns the underlying alterations in iron metabolism induced by chronic inflammation that result in anemia.

Ferric gluconate is highly efficacious in anemic hemodialysis patients with high serum ferritin and low transferrin saturation: results of the Dialysis Patients' Response to IV Iron with Elevated Ferritin (DRIVE) Study

Few data exist to guide treatment of anemic hemodialysis patients with high ferritin and low transferrin saturation (TSAT). The Dialysis Patients' Response to IV Iron with Elevated Ferritin (DRIVE) trial was designed to evaluate the efficacy of intravenous ferric gluconate in such patients. Inclusion criteria were hemoglobin <or=11 g/dl, ferritin 500 to 1200 ng/ml, TSAT <or=25%, and epoetin dosage >or=225 IU/kg per wk or >or=22,500 IU/wk. Patients with known infections or recent significant blood loss were excluded. Participants (n=134) were randomly assigned to no iron (control) or to ferric gluconate 125 mg intravenously with eight consecutive hemodialysis sessions (intravenous iron). At randomization, epoetin was increased 25% in both groups; further dosage changes were prohibited. At 6 wk, hemoglobin increased significantly more (P=0.028) in the intravenous iron group (1.6 +/- 1.3 g/dl) than in the control group (1.1 +/- 1.4 g/dl). Hemoglobin response occurred faster (P=0.035) and more patients responded after intravenous iron than in the control group (P=0.041). Ferritin <or=800 or >800 ng/ml had no relationship to the magnitude or likelihood of responsiveness to intravenous iron relative to the control group. Similarly, the superiority of intravenous iron compared with no iron was similar whether baseline TSAT was above or below the study median of 19%. Ferritin decreased in control subjects (-174 +/- 225 ng/ml) and increased after intravenous iron (173 +/- 272 ng/ml; P<0.001). Intravenous iron resulted in a greater increase in TSAT than in control subjects (7.5 +/- 7.4 versus 1.8 +/- 5.2%; P<0.001). Reticulocyte hemoglobin content fell only in control subjects, suggesting worsening iron deficiency. Administration of ferric gluconate (125 mg for eight treatments) is superior to no iron therapy in anemic dialysis patients receiving adequate epoetin dosages and have a ferritin 500 to 1200 ng/ml and TSAT <or=25%.

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.

Iron Supplementation in Renal Anemia

Iron-deficiency frequently develops in patients with chronic kidney disease who are treated with recombinant human erythropoietin (rHuEPO). It results in reduced effectiveness of anemia therapy; patients may fail to reach hemoglobin targets or may require excessively large doses of rHuEPO. It has been recognized widely that iron management, monitoring for iron deficiency, and effective iron supplementation forms a core component of anemia therapy. This review discusses the physiology of iron balance, derangements in iron balance in chronic kidney disease (CKD), and the diagnosis and treatment of iron deficiency in patients treated with rHuEPO.