Parenteral versus oral iron therapy for adults and children with chronic kidney disease

Parenteral iron therapy in children with iron deficiency anemia

Iron deficiency anemia (IDA) continues to be a global public health problem. Oral iron is the universally accepted first-line therapy, and most children have a prompt and favorable response to oral formulations. In subsets of children who fail to respond due to intolerance, poor adherence, or inadequate intestinal absorption, parenteral iron is indicated. Despite numerous studies in adults with IDA of diverse etiologies, pediatric studies on parenteral iron use are very limited. Although mostly retrospective and small, these studies have documented the efficacy and safety profile of intravenous iron formulations. In this editorial the author comments on the most important published data and underscores the need to seriously consider parenteral iron use in children unresponsive to oral therapy.

Anaesthetic Approach to Enhanced Recovery after Surgery for Kidney Transplantation: A Narrative Review

Enhanced recovery after surgery (ERAS) protocols are designed to reduce medical complications, the length of hospital stays (LoS), and healthcare costs. ERAS is considered safe and effective for kidney transplant (KTx) surgery. KTx recipients are often frail with multiple comorbidities. As these patients follow an extensive diagnostic pathway preoperatively, the ERAS protocol can ideally be implemented at this stage. Small singular changes in a long perioperative pathway can result in significant positive outcomes. We have investigated the current evidence for an ERAS pathway related to anaesthetic considerations in renal transplant surgery for adult recipients.

Iron-Deficiency in Atopic Diseases: Innate Immune Priming by Allergens and Siderophores

Although iron is one of the most abundant elements on earth, about a third of the world's population are affected by iron deficiency. Main drivers of iron deficiency are beside the chronic lack of dietary iron, a hampered uptake machinery as a result of immune activation. Macrophages are the principal cells distributing iron in the human body with their iron restriction skewing these cells to a more pro-inflammatory state. Consequently, iron deficiency has a pronounced impact on immune cells, favoring Th2-cell survival, immunoglobulin class switching and primes mast cells for degranulation. Iron deficiency during pregnancy increases the risk of atopic diseases in children, while both children and adults with allergy are more likely to have anemia. In contrast, an improved iron status seems to protect against allergy development. Here, the most important interconnections between iron metabolism and allergies, the effect of iron deprivation on distinct immune cell types, as well as the pathophysiology in atopic diseases are summarized. Although the main focus will be humans, we also compare them with innate defense and iron sequestration strategies of microbes, given, particularly, attention to catechol-siderophores. Similarly, the defense and nutritional strategies in plants with their inducible systemic acquired resistance by salicylic acid, which further leads to synthesis of flavonoids as well as pathogenesis-related proteins, will be elaborated as both are very important for understanding the etiology of allergic diseases. Many allergens, such as lipocalins and the pathogenesis-related proteins, are able to bind iron and either deprive or supply iron to immune cells. Thus, a locally induced iron deficiency will result in immune activation and allergic sensitization. However, the same proteins such as the whey protein beta-lactoglobulin can also transport this precious micronutrient to the host immune cells (holoBLG) and hinder their activation, promoting tolerance and protecting against allergy. Since 2019, several clinical trials have also been conducted in allergic subjects using holoBLG as a food for special medical purposes, leading to a reduction in the allergic symptom burden. Supplementation with nutrient-carrying lipocalin proteins can circumvent the mucosal block and nourish selectively immune cells, therefore representing a new dietary and causative approach to compensate for functional iron deficiency in allergy sufferers.

Preliminary experience on the use of sucrosomial iron in hemodialysis: focus on safety, hemoglobin maintenance and oxidative stress

PURPOSE

Iron is usually administered in hemodialysis patients by parenteral route, as oral absorption is poor due to high hepcidin levels. However, administrations of intravenous iron and iron overload are associated with high oxidative stress and systemic inflammation that can affect patient survival. With this study, we evaluated an alternative type of oral iron for the treatment of anemia in hemodialysis patients. The formulation consists in ferric pyrophosphate covered by phospholipids plus sucrose ester of fatty acid matrix, named sucrosomial iron, whose absorption is not influenced by hepcidin.

METHODS

Twenty-four (24) patients undergoing chronic hemodialysis switched iron supplementation from intravenous (ferric gluconate 62.5 mg weekly) to oral (sucrosomial iron, 90 mg weekly in 3 administrations of 30 mg) route for 3 months. Classical anemia, iron metabolism, inflammation and nutritional biomarkers were monitored, as well as biomarkers of oxidative stress, such as protein-bound di-tyrosines, protein carbonylation, advanced oxidation protein products and protein thiols.

RESULTS

Over the 3 months, hemoglobin values remained stable, as the values of hematocrit and mean corpuscular volume. In parallel, other anemia parameters dropped, including ferritin, transferrin saturation and serum iron. On the other side, nutritional biomarkers, such as total proteins and transferrin, increased significantly during the time frame. We also observed a significant decrease in white blood cells as well as a non-significant reduction in C-reactive protein and some oxidative stress biomarkers, such as protein carbonyls and di-tyrosines.

CONCLUSION

Our study demonstrates that a therapy with sucrosomial iron in hemodialysis patients is safe and can maintain stable hemoglobin levels in a three-month period with a possible beneficial effect on oxidative stress parameters. However, the reduction of ferritin and transferrin saturation suggests that a weekly dosage of 90 mg is not sufficient in hemodialysis patients in the long time to maintain hemoglobin.

Acquired Refractory Iron Deficiency Anemia

Anemia is a global health problem affecting one-third of the world population, and half of the cases are due to iron deficiency (ID). Iron deficiency anemia (IDA) is the leading cause of disability in several countries. Although multiple mechanisms may coexist, ID and IDA causes can be classified as i) insufficient iron intake for the body requirement, ii) reduced absorption, and iii) blood losses. Oral iron represents the mainstay of IDA treatment. IDA is defined as "refractory" when the hematologic response after 4 to 6 weeks of treatment with oral iron (an increase of >=1 g/dL of Hb) is absent. The cause of iron-refractory anemia is usually acquired and frequently related to gastrointestinal pathologies, although a rare genetic form called iron-refractory iron deficiency anemia (IRIDA) exists. In some pathological circumstances, either genetic or acquired, hepcidin increases, limiting the absorption in the gut, remobilization, and recycling of iron, thereby reducing iron plasma levels. Indeed, conditions with high hepcidin levels are often under-recognized as iron refractory, leading to inappropriate and unsuccessful treatments. This review provides an overview of the iron refractory anemia underlying conditions, from gastrointestinal pathologies to hepcidin dysregulation and iatrogenic or provoked conditions, and the specific diagnostic and treatment approach.

Ferric carboxymaltose vs. ferrous sulfate for the treatment of anemia in advanced chronic kidney disease: an observational retrospective study and cost analysis

In non-dialysis-dependent chronic kidney disease (NDD-CKD), erythropoiesis-stimulating agents (ESAs) and iron supplementation are essential for anemia management. Ferric carboxymaltose (FCM) is a relatively novel intravenous iron formulation used in different clinical settings, although scarce data exist in NDD-CKD patients. Primary objective of this study was to retrospectively evaluate the efficacy of FCM compared with oral ferrous sulfate for the treatment of iron-deficiency anemia in a cohort of NDD-CKD patients, considering also the treatment costs. This was a monocentric, retrospective observational study reviewing 349 NDD-CKD patients attending an outpatient clinic between June 2013 and December 2016. Patients were treated by either FCM intravenous infusion or oral ferrous sulfate. We collected serum values of hemoglobin, ferritin and transferrin saturation (TSAT) and ESAs doses at 12 and 18 months. The costs related to both treatments were also analysed. 239 patients were treated with FCM intravenous infusion and 110 patients with oral ferrous sulfate. The two groups were not statistically different for age, BMI and eGFR values. At 18 months, hemoglobin, serum ferritin and TSAT values increased significantly from baseline in the FCM group, compared with the ferrous sulfate group. ESAs dose and rate of infusion decreased only in the FCM group. At 18 months, the treatment costs, analysed per week, was higher in the ferrous sulfate group, compared with the FCM group, and this was mostly due to a reduction in ESAs prescription in the FCM group. Routine intravenous FCM treatment in an outpatient clinic of NDD-CKD patients results in better correction of iron-deficiency anemia when compared to ferrous sulfate. In addition to this, treating NDD-CKD patients with FCM leads to a significant reduction of the treatment costs by reducing ESAs use.

Anaemia and iron deficiency in patients with rheumatoid arthritis and other chronic diseases

Anaemia is one of the most common symptoms accompanying many chronic diseases, e.g. collagenases, neoplasms, and chronic inflammations (inflammatory bowel disease, chronic kidney disease and heart failure). Iron deficiency anaemia is the most common type of anaemia (80%). It affects 1% to 2% of the population. Iron deficiency (ID) – absolute or functional – is characterised by reduced ferritin levels and transferrin saturation (TSAT) of less than 20%. Iron deficiency is the most common dietary deficiency. However, iron deficiency might be one of the common causes of anaemia of chronic disease (ACD). Anaemia affects 33% to 60% of patients with RA. Rheumatoid arthritis (RA) is a chronic immune-mediated systemic connective tissue disease, in which chronic inflammation of the synovial tissue of the joints damages articular cartilages, bones and other joint structures. The prevalence of RA is approximately 0.3% to 2%. Low haemoglobin levels in RA patients are significantly correlated with disability, activity and duration of the disease as well as damage to joints and joint pain. Treatment of anaemia in RA patients includes iron supplementation, blood transfusions, the use of erythropoiesis-stimulating agents, and treatment of the underlying condition. Biological treatments used in RA patients, such as e.g. infliximab, tocilizumab and anakinra, not only slow the progression of joint involvement but also prevent anaemia.

Potential hazards of recent trends in liberal iron use for renal anemia

A randomized controlled trial,the Proactive IV Iron Therapy in Haemodialysis Patients (PIVOTAL), has recently shown that a high-dose (‘proactive’) intravenous iron regimen was superior to a low-dose (‘reactive’) regimen for hemodialysis patient outcomes and overall safety. However, even in the low-dose group, a substantial amount of iron was administered to maintain serum ferritin >200 ng/mL. This type of comparison may have strongly affected the safety results. Iron has two opposite effects on erythropoiesis: it activates erythroid differentiation directly by supplying iron but inhibits it indirectly by stimulating hepcidin and enhancing oxidative stress. Hepcidin plays an essential role not only in iron homeostasis and the anemia of chronic kidney disease, but also in its complications such as atherosclerosis and infection. Its main stimulation by iron—and to a lesser degree by inflammation—should urge clinicians to avoid prescribing excessive amounts of iron. Furthermore, as serum ferritin is closely correlated with serum hepcidin and iron storage, it would seem preferable to rely mainly on serum ferritin to adjust iron administration, defining an upper limit for risk reduction. Based on our estimations, the optimal range of serum ferritin is ∼50–150 ng/mL, which is precisely within the boundaries of iron management in Japan. Considering the contrasting ranges of target ferritin levels between end-stage renal disease patients in Japan and the rest of the world, the optimal range proposed by us will probably be considered as unacceptable by nephrologists abroad. Only well-balanced, randomized controlled trials with both erythropoiesis-stimulating agents and iron will allow us to settle this controversy.

Iron deficiency and supplementation in heart failure and chronic kidney disease

Iron is a key element for normal cellular function and plays a role in many cellular processes including mitochondrial respiration. The role of iron deficiency (ID) in heart failure (HF) has been a subject of debate amid increasing advocacy for intravenous (IV) supplementation. Both the definition and the approach to treatment of ID in HF have been adapted from the experience in patients with chronic kidney disease (CKD). In this review, we highlight the differences in regulatory mechanisms as well as pathophysiology of ID in CKD and HF population both at the systemic and cellular levels. We will review the major clinical trials in HF patients that have shown symptomatic benefit from IV iron supplementation but without effect on clinical outcomes. Intravenous iron loading bypasses the mechanisms that tightly regulate iron uptake and can potentially cause myocardial and endothelial damage by releasing reactive oxygen species. By contrast, newer oral iron preparations do not have similar toxicity concerns and might have a role in heart failure.

Assessment of cognitive functions and adaptive behavior in children with end-stage renal disease on regular hemodialysis

Chronic kidney disease (CKD) is defined by the Kidney Disease and Outcome Quality Initiative as a child who has kidney damage lasting for at least three months with or without decreased glomerular filtration rate. Hemodialysis (HD) means removal of waste products and extra fluid directly from the blood when the kidneys do not work properly. Studies aimed at investigating neurocognitive impairment in children with CKD have identified a wide range of delays in cognitive development. The aim of this study was to assess the cognitive functions and adaptive behavior in children with end-stage renal disease (ESRD) on regular HD. This case-controlled study was conducted on 30 children suffering from ESRD who were on treatment at the Pediatric Nephrology Unit of Tanta University Hospital. Thirty apparently healthy children served as a control group, in the period from January 2017 to January 2018. All children were subjected to full history taking, careful physical and neurological examination, specific investigations including assessment of intelligence quotient (IQ) using Stanford Binet test 5^th edition; assessment of adaptive behavior, assessment of executive functions by using Wisconsin Card Sorting Test; and continuous performance test. This study showed that mean values of IQ and the Vineland test were significantly lower among patients than controls. The study suggests that children with ESRD had lower IQ, adaptive behavior and executive functions than healthy control children.

The Impact of Iron Supplementation for Treating Anemia in Patients with Chronic Kidney Disease: Results from Pairwise and Network Meta-Analyses of Randomized Controlled Trials

After relative erythropoietin deficiency, iron deficiency is the second most important contributing factor for anemia in chronic kidney disease (CKD) patients. Iron supplementation is a crucial part of the treatment of anemia in CKD patients, and intravenous (IV) iron supplementation is considered to be superior to per os (PO) iron supplementation. The differences between the available formulations are poorly characterized. This report presents results from pairwise and network meta-analyses carried out after a comprehensive search in sources of published and unpublished studies, according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) recommendations (International prospective register of systematic reviews PROSPERO reference ID: CRD42020148155). Meta-analytic calculations were performed for the outcome of non-response to iron supplementation (i.e., hemoglobin (Hgb) increase of <0.5–1.0 g/dL, or initiation/intensification of erythropoiesis-stimulating agent (ESA) therapy, or increase/change of iron supplement, or requirements of blood transfusion). A total of 34 randomized controlled trials (RCT) were identified, providing numerical data for analyses covering 93.7% (n = 10.097) of the total study population. At the network level, iron supplementation seems to have a more protective effect against the outcome of non-response before the start of dialysis than once dialysis is initiated, and some preparations seem to be more potent (e.g., ferumoxytol, ferric carboxymaltose), compared to the rest of iron supplements assessed (surface under the cumulative ranking area (SUCRA) > 0.8). This study provides parameters for adequately following-up patients requiring iron supplementation, by presenting the most performing preparations, and, indirectly, by making it possible to identify good responders among all patients treated with these medicines.

Risk of iron overload with chronic indiscriminate use of intravenous iron products in ESRD and IBD populations

The routine use of recombinant erythropoiesis-stimulating agents (ESA) over the past three decades has enabled the partial correction of anaemia in most patients with end-stage renal disease (ESRD). Since ESA use frequently leads to iron deficiency, almost all ESA-treated haemodialysis patients worldwide receive intravenous iron (IV) to ensure sufficient available iron during ESA therapy. Patients with inflammatory bowel disease (IBD) are also often treated with IV iron preparations, as anaemia is common in IBD. Over the past few years, liver magnetic resonance imaging (MRI) has become the gold standard method for non-invasive diagnosis and follow-up of iron overload diseases. Studies using MRI to quantify liver iron concentration in ESRD have shown a link between high infused iron dose and risk of haemosiderosis in dialysis patients. In September 2017, the Pharmacovigilance Committee (PRAC) of the European Medicines Agency (EMA) considered convergent publications over the last few years on iatrogenic haemosiderosis in dialysis patients and requested that companies holding marketing authorization for iron products should investigate the risk of iron overload, particularly in patients with end-stage renal disease on dialysis and, by analogy, patients with IBD. We present a narrative review of data supporting the views and decision of the EMA, and then give our expert opinion on this controversial field of anaemia therapeutics.

Parenteral versus oral iron therapy for adults and children with chronic kidney disease

BACKGROUND

The anaemia seen in chronic kidney disease (CKD) may be exacerbated by iron deficiency. Iron can be provided through different routes, with advantages and drawbacks of each route. It remains unclear whether the potential harms and additional costs of intravenous (IV) compared with oral iron are justified. This is an update of a review first published in 2012.

OBJECTIVES

To determine the benefits and harms of IV iron supplementation compared with oral iron for anaemia in adults and children with CKD, including participants on dialysis, with kidney transplants and CKD not requiring dialysis.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 7 December 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs in which IV and oral routes of iron administration were compared in adults and children with CKD.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility, risk of bias, and extracted data. Results were reported as risk ratios (RR) with 95% confidence intervals (CI) for dichotomous outcomes. For continuous outcomes the mean difference (MD) was used or standardised mean difference (SMD) if different scales had been used. Statistical analyses were performed using the random-effects model. Subgroup analysis and univariate meta-regression were performed to investigate between study differences. The certainty of the evidence was assessed using GRADE.

MAIN RESULTS

We included 39 studies (3852 participants), 11 of which were added in this update. A low risk of bias was attributed to 20 (51%) studies for sequence generation, 14 (36%) studies for allocation concealment, 22 (56%) studies for attrition bias and 20 (51%) for selective outcome reporting. All studies were at a high risk of performance bias. However, all studies were considered at low risk of detection bias because the primary outcome in all studies was laboratory-based and unlikely to be influenced by lack of blinding.There is insufficient evidence to suggest that IV iron compared with oral iron makes any difference to death (all causes) (11 studies, 1952 participants: RR 1.12, 95% CI 0.64, 1.94) (absolute effect: 33 participants per 1000 with IV iron versus 31 per 1000 with oral iron), the number of participants needing to start dialysis (4 studies, 743 participants: RR 0.81, 95% CI 0.41, 1.61) or the number needing blood transfusions (5 studies, 774 participants: RR 0.86, 95% CI 0.55, 1.34) (absolute effect: 87 per 1,000 with IV iron versus 101 per 1,000 with oral iron). These analyses were assessed as having low certainty evidence. It is uncertain whether IV iron compared with oral iron reduces cardiovascular death because the certainty of this evidence was very low (3 studies, 206 participants: RR 1.71, 95% CI 0.41 to 7.18). Quality of life was reported in five studies with four reporting no difference between treatment groups and one reporting improvement in participants treated with IV iron.IV iron compared with oral iron may increase the numbers of participants, who experience allergic reactions or hypotension (15 studies, 2607 participants: RR 3.56, 95% CI 1.88 to 6.74) (absolute harm: 24 per 1000 with IV iron versus 7 per 1000) but may reduce the number of participants with all gastrointestinal adverse effects (14 studies, 1986 participants: RR 0.47, 95% CI 0.33 to 0.66) (absolute benefit: 150 per 1000 with IV iron versus 319 per 1000). These analyses were assessed as having low certainty evidence.IV iron compared with oral iron may increase the number of participants who achieve target haemoglobin (13 studies, 2206 participants: RR 1.71, 95% CI 1.43 to 2.04) (absolute benefit: 542 participants per 1,000 with IV iron versus 317 per 1000 with oral iron), increased haemoglobin (31 studies, 3373 participants: MD 0.72 g/dL, 95% CI 0.39 to 1.05); ferritin (33 studies, 3389 participants: MD 224.84 µg/L, 95% CI 165.85 to 283.83) and transferrin saturation (27 studies, 3089 participants: MD 7.69%, 95% CI 5.10 to 10.28), and may reduce the dose required of erythropoietin-stimulating agents (ESAs) (11 studies, 522 participants: SMD -0.72, 95% CI -1.12 to -0.31) while making little or no difference to glomerular filtration rate (8 studies, 1052 participants: 0.83 mL/min, 95% CI -0.79 to 2.44). All analyses were assessed as having low certainty evidence. There were moderate to high degrees of heterogeneity in these analyses but in meta-regression, definite reasons for this could not be determined.

AUTHORS' CONCLUSIONS

The included studies provide low certainty evidence that IV iron compared with oral iron increases haemoglobin, ferritin and transferrin levels in CKD participants, increases the number of participants who achieve target haemoglobin and reduces ESA requirements. However, there is insufficient evidence to determine whether IV iron compared with oral iron influences death (all causes), cardiovascular death and quality of life though most studies reported only short periods of follow-up. Adverse effects were reported in only 50% of included studies. We therefore suggest that further studies that focus on patient-centred outcomes with longer follow-up periods are needed to determine if the use of IV iron is justified on the basis of reductions in ESA dose and cost, improvements in patient quality of life, and with few serious adverse effects.

Impact of Inflammation on Ferritin, Hepcidin and the Management of Iron Deficiency Anemia in Chronic Kidney Disease

Iron deficiency anemia (IDA) is a major problem in chronic kidney disease (CKD), causing increased mortality. Ferritin stores iron, representing iron status. Hepcidin binds to ferroportin, thereby inhibiting iron absorption/efflux. Inflammation in CKD increases ferritin and hepcidin independent of iron status, which reduce iron availability. While intravenous iron therapy (IIT) is superior to oral iron therapy (OIT) in CKD patients with inflammation, OIT is as effective as IIT in those without. Inflammation reduces predictive values of ferritin and hepcidin for iron status and responsiveness to iron therapy. Upper limit of ferritin to predict iron overload is higher in CKD patients with inflammation than in those without. However, magnetic resonance imaging studies show lower cutoff levels of serum ferritin to predict iron overload in dialysis patients with apparent inflammation than upper limit of ferritin proposed by international guidelines. Compared to CKD patients with inflammation, optimal ferritin levels for IDA are lower in those without, requiring reduced iron dose and leading to decreased mortality. The management of IDA should differ between CKD patients with and without inflammation and include minimization of inflammation. Further studies are needed to determine the impact of inflammation on ferritin, hepcidin and therapeutic strategy for IDA in CKD.

Optimal Serum Ferritin Levels for Iron Deficiency Anemia during Oral Iron Therapy (OIT) in Japanese Hemodialysis Patients with Minor Inflammation and Benefit of Intravenous Iron Therapy for OIT-Nonresponders

Background: We determined optimal serum ferritin for oral iron therapy (OIT) in hemodialysis (HD) patients with iron deficiency anemia (IDA)/minor inflammation, and benefit of intravenous iron therapy (IIT) for OIT-nonresponders. Methods: Inclusion criteria were IDA (Hb <120 g/L, serum ferritin <227.4 pmol/L). Exclusion criteria were inflammation (C-reactive protein (CRP) ≥ 5 mg/L), bleeding, or cancer. IIT was withheld >3 months before the study. ΔHb ≥ 20 g/L above baseline or maintaining target Hb (tHB; 120-130 g/L) was considered responsive. Fifty-one patients received OIT (ferrous fumarate, 50 mg/day) for 3 months; this continued in OIT-responders but was switched to IIT (saccharated ferric oxide, 40 mg/week) in OIT-nonresponders for 4 months. All received continuous erythropoietin receptor activator (CERA). Hb, ferritin, hepcidin-25, and CERA dose were measured. Results: Demographics before OIT were similar between OIT-responders and OIT-nonresponders except low Hb and high triglycerides in OIT-nonresponders. Thirty-nine were OIT-responders with reduced CERA dose. Hb rose with a peak at 5 months. Ferritin and hepcidin-25 continuously increased. Hb positively correlated with ferritin in OIT-responders (r = 0.913, p = 0.03) till 5 months after OIT. The correlation equation estimated optimal ferritin of 30-40 ng/mL using tHb (120-130 g/L). Seven OIT-nonresponders were IIT-responders. Conclusions: Optimal serum ferritin for OIT is 67.4-89.9 pmol/L in HD patients with IDA/minor inflammation. IIT may be a second line of treatment for OIT-nonreponders.

Safety of Intravenous Iron in Dialysis: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

The safety of intravenous iron dosing in dialysis is uncertain. Higher-dose intravenous iron may be associated with a higher risk of infections, cardiovascular events, hospitalizations, and mortality. This systematic review aimed to determine the safety of higher-dose versus lower-dose intravenous iron, oral iron, or no iron supplementation in adult patients treated with dialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We searched Medline, EMBASE, Cochrane library, and CINAHL from inception to January 6, 2017 for randomized, controlled trials and observational studies comparing higher-dose intravenous iron with lower-dose intravenous iron, oral iron, or no iron in patients treated with dialysis that had all-cause mortality, infection, cardiovascular events, or hospitalizations as outcomes.

RESULTS

Of the 2231 eligible studies, seven randomized, controlled trials and 15 observational studies met inclusion criteria. The randomized, controlled trials showed no association between higher-dose intravenous iron (>400 mg/mo for most studies) and mortality (six studies; n=970; pooled relative risk, 0.93; 95% confidence interval, 0.47 to 1.84; follow-up ranging from 35 days to 26 months) or infection (four studies; n=743; relative risk, 1.02; 95% confidence interval, 0.74 to 1.41). The observational studies showed no association between higher-dose intravenous iron (>200 mg/mo for most studies) and mortality (eight studies; n=241,408; hazard ratio, 1.09; 95% confidence interval, 0.98 to 1.21; follow-up ranging from 3 to 24 months), infection (eight studies; n=135,532; pooled hazard ratio, 1.13; 95% confidence interval, 0.99 to 1.28), cardiovascular events (seven studies; n=135,675; hazard ratio, 1.18; 95% confidence interval, 0.90 to 1.56), or hospitalizations (five studies; n=134,324; hazard ratio, 1.08; 95% confidence interval, 0.97 to 1.19).

CONCLUSIONS

Higher-dose intravenous iron does not seem to be associated with higher risk of mortality, infection, cardiovascular events, or hospitalizations in adult patients on dialysis. Strength of this finding is limited by small numbers of participants and events in the randomized, controlled trials and statistical heterogeneity in observational studies.

Intravenous iron and erythropoiesis-stimulating agents in haemodialysis: A systematic review and meta-analysis

AIM

Higher dosages of erythropoiesis-stimulating agents (ESAs) have been associated with adverse effects. Intravenous iron is used to optimize ESA response and reduces ESA doses in haemodialysis patients; this meta-analysis evaluates the magnitude of this effect.

METHODS

A literature search was performed using MEDLINE, Embase and the Cochrane Collaboration Central Register of Clinical Trials from inception until December 2014, to identify randomized controlled trials of intravenous iron and ESA, in patients undergoing haemodialysis for end-stage kidney disease. Dosing of IV iron in concordance with the Kidney Disease Improving Global Outcomes guidelines was considered optimal iron therapy.

RESULTS

Of the 28 randomized controlled trials identified, seven met the criteria for inclusion in the meta-analysis. Results of random-effects meta-analysis show a statistically significant weighted mean (95% CI) difference of -1733 [-3073, -392] units/week in ESA dose for optimal iron versus suboptimal iron. The weighted average change in ESA dose was a reduction of 23% (range -7% to -55%) attributable to appropriate dosing of intravenous iron. A comparison of intravenous iron versus oral iron/no iron (five trials) showed a greater reduction in ESA dose, although this did not reach statistical significance (weighted mean difference, 95% CI: -2,433 [-5183, 318] units/week). The weighted average change in ESA dose across the five trials was a reduction of 31% (range -8% to -55%).

CONCLUSION

Significant reductions in ESA dosing may be achieved with optimal intravenous iron usage in the haemodialysis population, and suboptimal iron use may require higher ESA dosing to manage anaemia.

Oral Ferric Citrate Hydrate Associated With Less Oxidative Stress Than Intravenous Saccharated Ferric Oxide

Introduction

A recent study suggested that orally dosed ferric citrate hydrate (FC) corrects renal anemia in patients on hemodialysis (HD), suggesting biological differences in effects of iron supplementation using different routes of administration. To address this issue, the present study compared oral FC with i.v. saccharated ferric oxide (FO) in stable HD patients.

Methods

Participants comprised 6 patients administered 3 consecutive protocols in the first HD session of the week in a fasting state: nothing given, as control (C); oral load of FC (480 mg iron), and 5 minutes of i.v. FO (40 mg iron). Iron dynamics in the body and biological impact on redox-inflammation status during the study (6 hours) were examined.

Results

Significant increases in serum iron and transferrin saturation were seen with both FC and FO. Regarding total iron-binding capacity as the sum of serum iron and unsaturated iron-binding capacity, no changes were found in FC, whereas significant increases were seen in FO (appearance of non–transferrin-binding iron [NTBI]), despite the lower serum iron levels in FO. Compared with C, increases were seen in serum myeloperoxidase (oxidative marker) with accompanying significant decreases in thioredoxin (antioxidant) in FO, whereas no changes were found in FC.

Conclusion

Oral FC differs from i.v. FO in areas such as less NTBI generation and less induction of oxidative stress. The result indicates potential clinical benefits of oral FC in terms of iron supplementation for renal anemia in HD patients.

Clinical management of iron deficiency anemia in adults: Systemic review on advances in diagnosis and treatment

Global burden disease studies point out that one of the top cause-specific anemias is iron deficiency (ID). Recent advances in knowledge of iron homeostasis have shown that fragile patients are a new target population in which the correction of ID might impact their morbidity, mortality and quality of life. We did a systematic review using specific search strategy, carried out the review of PubMed database, Cochrane Database of systemic reviews and international guidelines on diagnosis and clinical management of ID from 2010 to 2016. The International guidelines were limited to those with peer-review process and published in journal present in citation index database. The eligible studies show that serum ferritin and transferrin saturation are the key tests in early decision-making process to identify iron deficiency anemia (IDA). The clinician has to carefully consider fragile and high-risk subset of patients such as elders or individuals with chronic diseases (i.e chronic kidney disease, inflammatory bowel disease, chronic heart failure). Treatment is based on iron supplementation. Infusion route should be preferentially considered in frail patients especially in the view of new iron available formulations. The available evidences indicate that (i) recurrent IDA should always be investigated, considering uncommon causes; (ii) IDA might worse the performance and the clinical outcome of fragile and high-risk patients and require an intensive treatment.

Iron Therapy in Patients with Heart Failure and Iron Deficiency: Review of Iron Preparations for Practitioners

In patients with heart failure (HF), iron deficiency (ID) correlates with decreased exercise capacity and poor health-related quality of life, and predicts worse outcomes. Both absolute (depleted iron stores) and functional (where iron is unavailable for dedicated tissues) ID can be easily evaluated in patients with HF using standard laboratory tests (assessment of serum ferritin and transferrin saturation). Intravenous iron therapy in iron-deficient patients with HF and reduced ejection fraction has been shown to alleviate HF symptoms and improve exercise capacity and quality of life. In this paper, we provide information on how to diagnose ID in HF. Further we discuss pros and cons of different iron preparations and discuss the results of major trials implementing iron supplementation in HF patients, in order to provide practical guidance for clinicians on how to manage ID in patients with HF.

Iatrogenic Iron Overload in Dialysis Patients at the Beginning of the 21st Century

Iron overload used to be considered rare in hemodialysis patients but its clinical frequency is now increasingly realized. The liver is the main site of iron storage and the liver iron concentration (LIC) is closely correlated with total iron stores in patients with secondary hemosideroses and genetic hemochromatosis. Magnetic resonance imaging is now the gold standard method for LIC estimation and monitoring in non-renal patients. Studies of LIC in hemodialysis patients by quantitative magnetic resonance imaging and magnetic susceptometry have demonstrated a strong relation between the risk of iron overload and the use of intravenous (IV) iron products prescribed at doses determined by the iron biomarker cutoffs contained in current anemia management guidelines. These findings have challenged the validity of both iron biomarker cutoffs and current clinical guidelines, especially with respect to recommended IV iron doses. Three long-term observational studies have recently suggested that excessive IV iron doses may be associated with an increased risk of cardiovascular events and death in hemodialysis patients. We postulate that iatrogenic iron overload in the era of erythropoiesis-stimulating agents may silently increase complications in dialysis patients without creating frank clinical signs and symptoms. High hepcidin-25 levels were recently linked to fatal and nonfatal cardiovascular events in dialysis patients. It is therefore tempting to postulate that the main pathophysiological pathway leading to these events may involve the pleiotropic master hormone hepcidin (synergized by fibroblast growth factor 23), which regulates iron metabolism. Oxidative stress as a result of IV iron infusions and iron overload, by releasing labile non-transferrin-bound iron, might represent a ‘second hit’ on the vascular bed. Finally, iron deposition in the myocardium of patients with severe iron overload might also play a role in the pathogenesis of sudden death in some patients.

A comprehensive literatures update of clinical researches of superparamagnetic resonance iron oxide nanoparticles for magnetic resonance imaging

This paper aims to update the clinical researches using superparamagnetic iron oxide (SPIO) nanoparticles as magnetic resonance imaging (MRI) contrast agent published during the past five years. PubMed database was used for literature search, and the search terms were (SPIO OR superparamagnetic iron oxide OR Resovist OR Ferumoxytol OR Ferumoxtran-10) AND (MRI OR magnetic resonance imaging). The literature search results show clinical research on SPIO remains robust, particularly fuelled by the approval of ferumoxytol for intravenously administration. SPIOs have been tested on MR angiography, sentinel lymph node detection, lymph node metastasis evaluation; inflammation evaluation; blood volume measurement; as well as liver imaging. Two experimental SPIOs with unique potentials are also discussed in this review. A curcumin-conjugated SPIO can penetrate brain blood barrier (BBB) and bind to amyloid plaques in Alzheime's disease transgenic mice brain, and thereafter detectable by MRI. Another SPIO was fabricated with a core of Fe3O4 nanoparticle and a shell coating of concentrated hydrophilic polymer brushes and are almost not taken by peripheral macrophages as well as by mononuclear phagocytes and reticuloendothelial system (RES) due to the suppression of non-specific protein binding caused by their stealthy ''brush-afforded'' structure. This SPIO may offer potentials for the applications such as drug targeting and tissue or organ imaging other than liver and lymph nodes.

Comparison of the Effects of Iron Oxide, as a New Form of Iron Supplement, and Ferrous Sulfate on the Blood Levels of Iron and Total Iron-Binding Globulin in the Rabbit

Iron oxide is an important biological agent that has a key role in medical processes; however, the mechanism whereby it provides iron for human and animal cells and its biological uses remains unclear. We aimed to evaluate the effects of oral iron oxide on serum iron status and compare the results with those of iron sulfate as a reference salt. Fifteen adult rabbits were divided into 3 groups of 5 each: control group, iron sulfate group, and iron oxide group. The groups received doses of 3.3, 10, and 33 mg/kg in 3 experiments. Venous blood samples were obtained just before the oral administration of iron sulfate and iron oxide (3.3 mg/kg). More blood samples were taken 3 times at the time points of 1, 6, and 12 hours after the administration of the solutions. Serum was separated for the measurement of iron (Fe) and total iron-binding globulin (TIBG) with routine methods. One week later, the same experiment was repeated with 10 mg/kg of iron sulfate and iron oxide; and 1 week later after the second experiment, again the same experiment was repeated with 33 mg/kg of iron sulfate and iron oxide. The results showed that 33 mg/kg of iron sulfate 1 hour after treatment caused a significant difference in the Fe and TIBG levels between all the groups (P=0.014 for Fe and P=0.027 for TIBG). Our data showed that the absorption of iron oxide was similar to that of ferrous sulfate and in high doses was as useful as iron supplement.

Comparison of short-term efficacy of iron sucrose with those of ferric chloride in hemodialysis patients: An open-label study

Background:

It is intriguing and imperative that the comparison of the iron preparations in hemodialysis (HD) patients. This study aimed to observe the short-term efficacy of parenteral iron sucrose and ferric chloride in HD patients.

Materials and Methods:

This was a consecutive 10-week single-blind study in Taiwan. An intravenous iron supplement of 100 mg/week was administered as an infusion in 100 ml of normal saline, until a total dose of 1000 mg was achieved. The primary outcome was evaluated by the changes in serum hematocrit (Hct) levels. The changes in serum Hct and iron indices were evaluated every 2 weeks for 10 weeks. The results were collected from 21 April to 4 July 2013.

Results:

A total of 56 HD patients completed the study. Subjects were randomized into an iron sucrose group (26 patients) and a ferric chloride group (30 patients). Between the two treatment groups, there were no statistically significant differences in the change in serum Hct, ferritin, iron, or total iron binding capacity (P > 0.05). In the iron sucrose group, the increase in Hct levels was statistically significant at weeks 4, 8, and 10. In the ferric chloride group, the increase in Hct levels was statistically significant at week 8. No obvious major side effects were observed in both groups.

Conclusion:

In the study subjects, parenteral iron sucrose was as effective and safe as ferric chloride for treating anemia in HD patients.

Iron supplementation to treat anaemia in adult critical care patients: a systematic review and meta-analysis

BACKGROUND

Anaemia affects 60-80 % of patients admitted to intensive care units (ICUs). Allogeneic red blood cell (RBC) transfusions remain the mainstay of treatment for anaemia but are associated with risks and are costly. Our objective was to assess the efficacy and safety of iron supplementation by any route, in anaemic patients in adult ICUs.

METHODS

Electronic databases (CENTRAL, MEDLINE, EMBASE) were searched through March 2016 for randomized controlled trials (RCT)s comparing iron by any route with placebo/no iron. Primary outcomes were red blood cell transfusions and mean haemoglobin concentration. Secondary outcomes included mortality, infection, ICU and hospital length of stay, mean difference (MD) in iron biomarkers, health-related quality of life and adverse events.

RESULTS

Five RCTs recruiting 665 patients met the inclusion criteria; intravenous iron was tested in four of the RCTs. There was no difference in allogeneic RBC transfusion requirements (relative risk 0.87, 95 % confidence interval (CI) 0.70 to 1.07, p = 0.18, five trials) or mean number of RBC units transfused (MD -0.45, 95 % CI -1.34 to 0.43, p = 0.32, two trials) in patients receiving or not receiving iron. Similarly, there was no difference between groups in haemoglobin at short-term (up to 10 days) (MD -0.25, 95 % CI -0.79 to 0.28, p = 0.35, three trials) or mid-term follow up (last measured time point in hospital or end of trial) (MD 0.21, 95 % CI -0.13 to 0.55, p = 0.23, three trials). There was no difference in secondary outcomes of mortality, in-hospital infection, or length of stay. Risk of bias was generally low although three trials had high risk of attrition bias; only one trial had low risk of bias across all domains.

CONCLUSION

Iron supplementation does not reduce RBC transfusion requirements in critically ill adults, but there is considerable heterogeneity between trials in study design, nature of interventions, and outcomes. Well-designed trials are needed to investigate the optimal iron dosing regimens and strategies to identify which patients are most likely to benefit from iron, together with patient-focused outcomes.

TRIAL REGISTRATION

PROSPERO International prospective register of systematic reviews CRD42015016627 . Registered 2 March 2015.

The rise and rise of randomized clinical evidence in Sub-Saharan Africa

Sub-Saharan Africa is facing a rising tide of chronic disease, including chronic kidney disease, but the current research literature provides little evidence to guide the practice of nephrology in resource-poor settings. In this issue of CKJ, Waziri & Bello present a trial of two formulations of intravenous iron for patients with anaemia of chronic kidney disease in Nigeria. This study typifies a growing body of work from researchers from low-middle income countries addressing the evidence gaps that they meet in their everyday practice. Collaboration with clinical trialists and health economists from the global renal research community is suggested as an important way to expand, at low cost, the randomized evidence-base in this region.

[Diagnostic approach to iron deficiency anemia]

Anemia affects a fourth of the global population, with iron deficiency remaining the primary cause. It is associated with diminished work capacity, fatigue, impaired cognitive function, and can negatively impact the course of diseases like chronic heart failure or chronic kidney disease. Treatment options include oral and intravenous iron; however, conditions such as inflammatory bowel disease, celiac disease, or autoimmune gastritis can diminish the efficacy of oral iron. Timely recognition of iron deficiency anemia and administration of appropriate therapy not only improves quality of life, but also reduces the need for blood transfusions. Proper selection of iron-deficient patients for whom further diagnostic testing is necessary facilitates identification of underlying diseases that require specific treatment, and avoids unnecessary invasive testing.

Controversial issues in CKD clinical practice: position statement of the CKD-treatment working group of the Italian Society of Nephrology

This position paper of the study group "Conservative treatment of Chronic Kidney Disease-CKD" of the Italian Society of Nephrology addresses major practical, unresolved, issues related to the conservative treatment of chronic renal disease. Specifically, controversial topics from everyday clinical nephrology practice which cannot find a clear, definitive answer in the current literature or in nephrology guidelines are discussed. The paper reports the point of view of the study group. Concise and practical advice is given on several common issues: renal biopsy in diabetes; dual blockade of the renin-angiotensin-aldosterone system (RAAS); management of iron deficiency; low protein diet; dietary salt intake; bicarbonate supplementation; treatment of obesity; the choice of conservative therapy vs. dialysis. For each topic synthetic statements, guideline-style, are reported.

Standardised Outcomes in Nephrology-Children and Adolescents (SONG-Kids): a protocol for establishing a core outcome set for children with chronic kidney disease

Background

Children with chronic kidney disease (CKD), requiring dialysis or kidney transplantation, have a mortality rate of up to 30-fold higher than the general aged-matched population, and severely impaired quality of life. Symptoms such as fatigue and pain are prevalent and debilitating. Children with CKD are at risk of cognitive impairment, and poorer educational, vocational, and psychosocial outcomes compared with their well peers, which have consequences through to adulthood. Treatment regimens for children with CKD are long-term, complex, and highly intrusive. While many trials have been conducted to improve outcomes in children with CKD, the outcomes measured and reported are often not relevant to patients and clinicians, and are highly variable. These problems can diminish the value of trials as a means to improve the lives of children with CKD. The Standardised Outcomes in Nephrology—Children and Adolescents (SONG-Kids) study aims to develop a core outcome set for trials in children and adolescents with any stage of CKD that is based on the shared priorities of all stakeholders.

Methods/Design

SONG-Kids involves five phases: a systematic review to identify outcomes (both domains and measures) that have been reported in randomised controlled trials involving children aged up to 21 years with CKD; focus groups (using nominal group technique) with adolescent patients and caregivers of paediatric patients (all ages) to identify outcomes that are relevant and important to patients and their family and the reasons for their choices; semistructured key informant interviews with health professionals involved in the care of children with CKD to ascertain their views on establishing core outcomes in paediatric nephrology; an international three-round online Delphi survey with patients, caregivers, clinicians, researchers, policy-makers, and members from industry to develop consensus on important outcome domains; and a stakeholder workshop to review and finalise the set of core outcome domains for trials in children with CKD (including nondialysis-dependent, dialysis, and kidney transplantation).

Discussion

Establishing a core outcome set to be reported in all trials conducted in children with any stage of CKD will enhance the relevance, transparency, and impact of research to improve the lives of children and adolescents with CKD.

Chronic kidney disease in children

Chronic kidney disease (CKD) is a major health problem worldwide. Although relatively uncommon in children, it can be a devastating illness with many long-term consequences. CKD presents unique features in childhood and may be considered, at least in part, as a stand-alone nosologic entity. Moreover, some typical features of paediatric CKD, such as the disease aetiology or cardiovascular complications, will not only influence the child's health, but also have long-term impact on the life of the adult that they will become. In this review we will focus on the unique issues of paediatric CKD, in terms of aetiology, clinical features and treatment. In addition, we will discuss factors related to CKD that start during childhood and require appropriate treatments in order to optimize health outcomes and transition to nephrologist management in adult life.

Systematic review and meta-analysis of iron therapy in anaemic adults without chronic kidney disease: updated and abridged Cochrane review

AIMS

Anaemia is increasingly recognized as having an independent impact upon patient outcomes in cardiac disease. The role of novel iron therapies to treat anaemia is increasing. This systematic review and meta-analysis assesses the efficacy and safety of iron therapies for the treatment of adults with anaemia.

METHODS AND RESULTS

Electronic databases and search engines were searched as per Cochrane methodology. Randomized controlled trials (RCTs) of iron vs. inactive control or placebo, as well as alternative formulations, doses, and routes in anaemic adults without chronic kidney disease or in the peri-partum period were eligible. The primary outcome of interest was mortality at 1 year. Secondary outcomes were blood transfusion, haemoglobin levels, quality of life, serious adverse events, and length of hospital stay. A total of 64 RCTs (including five studies of heart failure patients) comprising 9004 participants were included. None of the studies was at a low risk of bias. There were no statistically significant differences in mortality between iron and inactive control. Both oral and parenteral iron significantly reduced the proportion of patients requiring blood transfusion compared with inactive control [risk ratio (RR) 0.66, 95% confidence interval (CI) 0.48-0.90; and RR 0.84, 95% CI 0.73-0.97, respectively]. Haemoglobin was increased more by both oral and parenteral iron compared with inactive control [mean difference (MD) 0.91 g/dL, 95% CI 0.48 to 1.35; and MD 1.04, 95% CI 0.52 to 1.57, respectively], and parenteral iron demonstrated a greater increase when compared with oral iron (MD 0.53 g/dL, 95% CI 0.31-0.75). In all comparisons, there were no differences in the results comparing patients with and without heart failure.

CONCLUSION

Both oral and parenteral iron are shown to decrease the proportion of people who require blood transfusion and increase haemoglobin levels, without any benefit on mortality. Further trials at a low risk of bias, powered to measure clinically significant endpoints, are still required.

Iron deficiency anaemia

Anaemia affects roughly a third of the world's population; half the cases are due to iron deficiency. It is a major and global public health problem that affects maternal and child mortality, physical performance, and referral to health-care professionals. Children aged 0-5 years, women of childbearing age, and pregnant women are particularly at risk. Several chronic diseases are frequently associated with iron deficiency anaemia--notably chronic kidney disease, chronic heart failure, cancer, and inflammatory bowel disease. Measurement of serum ferritin, transferrin saturation, serum soluble transferrin receptors, and the serum soluble transferrin receptors-ferritin index are more accurate than classic red cell indices in the diagnosis of iron deficiency anaemia. In addition to the search for and treatment of the cause of iron deficiency, treatment strategies encompass prevention, including food fortification and iron supplementation. Oral iron is usually recommended as first-line therapy, but the most recent intravenous iron formulations, which have been available for nearly a decade, seem to replenish iron stores safely and effectively. Hepcidin has a key role in iron homoeostasis and could be a future diagnostic and therapeutic target. In this Seminar, we discuss the clinical presentation, epidemiology, pathophysiology, diagnosis, and acute management of iron deficiency anaemia, and outstanding research questions for treatment.

Impact of European medicines agency recommendations for hypersensitivity reactions on intravenous iron prescription in haemodialysis centres of the Lombardy region

BACKGROUND

The European Medicines Agency (EMA) has recommended measures to minimize the risk of hypersensitivity reactions (HSRs) to intravenous iron (IVFe). We analysed the effects of these recommendations on IVFe clinical management among haemodialysis centres (HDCs) in Lombardy, Italy.

MATERIALS AND METHODS

A questionnaire was sent to all 117 HDCs to collect information on centre characteristics, e.g. HDC type [hospital centre (HC) vs. centre with limited assistance (CAL)], presence/absence of intensive care unit (ICU) and/or emergency trained staff, IVFe therapy regarding molecules, administration modalities, side effects, and percentage variations in iron prescription between 2014 and 2013 (outcome, Δ-IVFe%). A linear regression model was applied to evaluate the focus effect (β) of HDC type on the outcome, controlling for possible confounding effects of the other characteristics.

RESULTS

Response rate was 73.5 %. IVFe therapy was used in 69.1 % (HDC range 11-100) of patients. Following EMA recommendations, prescription was reduced by 12.6 %, with the largest reduction observed in CALs. No severe HSRs were reported. HCs had more frequently an ICU [97.2 vs. 20 %, odds ratio (OR) = 63.6 (95 % confidence interval 15.56; 537.47), p < 0.001], emergency trained staff [97.2 vs. 61.2 %, OR = 10.7 (2.68; 85.33), p < 0.001] and instrumental facilities (91.7 vs. 58 %, OR = 5.8 (2.03; 23.55), p < 0.001] than CALs. Linear regression demonstrated a significant raw effect of HDC type on Δ- IVFe% [β =  19.6 (9.82; 30.63), p < 0.001]. No association was found when HDC type was adjusted for ICU-presence [β = 6.7 (-2.32; 18.30), p = 0.199] or for all-confounding factors [β = 5.6 (-5.50; 17.08), p = 0.337].

CONCLUSIONS

This survey shows a disparity in IVFe therapy prescription following EMA recommendations, which is largely influenced by the presence/absence of ICUs in HD centres.

Drug therapies to delay the progression of chronic kidney disease

Chronic kidney disease (CKD) is associated with significant morbidity and mortality, impacted not alone by progression to end-stage kidney disease, but also by the high associated incidence of cardiovascular events and related mortality. Despite our current understanding of the pathogenesis of CKD and the treatments available, the reported incidence of CKD continues to rise worldwide, and is often referred to as the silent public healthcare epidemic. The significant cost to patient wellbeing and to the economy of managing the later stages of CKD have prompted efforts to develop interventions to delay the development and progression of this syndrome. In this article, we review established and novel agents that may aid in delaying the progression of CKD and improve patient outcomes.

A randomized, open-label trial of iron isomaltoside 1000 (Monofer®) compared with iron sucrose (Venofer®) as maintenance therapy in haemodialysis patients

BACKGROUND

Iron deficiency anaemia is common in patients with chronic kidney disease, and intravenous iron is the preferred treatment for those on haemodialysis. The aim of this trial was to compare the efficacy and safety of iron isomaltoside 1000 (Monofer®) with iron sucrose (Venofer®) in haemodialysis patients.

METHODS

This was an open-label, randomized, multicentre, non-inferiority trial conducted in 351 haemodialysis subjects randomized 2:1 to either iron isomaltoside 1000 (Group A) or iron sucrose (Group B). Subjects in Group A were equally divided into A1 (500 mg single bolus injection) and A2 (500 mg split dose). Group B were also treated with 500 mg split dose. The primary end point was the proportion of subjects with haemoglobin (Hb) in the target range 9.5-12.5 g/dL at 6 weeks. Secondary outcome measures included haematology parameters and safety parameters.

RESULTS

A total of 351 subjects were enrolled. Both treatments showed similar efficacy with >82% of subjects with Hb in the target range (non-inferiority, P = 0.01). Similar results were found when comparing subgroups A1 and A2 with Group B. No statistical significant change in Hb concentration was found between any of the groups. There was a significant increase in ferritin from baseline to Weeks 1, 2 and 4 in Group A compared with Group B (Weeks 1 and 2: P < 0.001; Week 4: P = 0.002). There was a significant higher increase in reticulocyte count in Group A compared with Group B at Week 1 (P < 0.001). The frequency, type and severity of adverse events were similar.

CONCLUSIONS

Iron isomaltoside 1000 and iron sucrose have comparative efficacy in maintaining Hb concentrations in haemodialysis subjects and both preparations were well tolerated with a similar short-term safety profile.

Is Correction of Iron Deficiency a New Addition to the Treatment of the Heart Failure?

Anemia is present in about 40% of heart failure (HF) patients. Iron deficiency (ID) is present in about 60% of the patients with anemia (about 24% of all HF patients) and in about 40% of patients without anemia (about 24% of all HF patients). Thus ID is present in about half the patients with HF. The ID in HF is associated with reduced iron stores in the bone marrow and the heart. ID is an independent risk factor for severity and worsening of the HF. Correction of ID with intravenous (IV) iron usually corrects both the anemia and the ID. Currently used IV iron preparations are very safe and effective in treating the ID in HF whereas little information is available on the effectiveness of oral iron. In HF IV iron correction of ID is associated with improvement in functional status, exercise capacity, quality of life and, in some studies, improvement in rate of hospitalization for HF, cardiac structure and function, and renal function. Large long-term adequately-controlled intervention studies are needed to clarify the effect of IV iron in HF. Several heart associations suggest that ID should be routinely sought for in all HF patients and corrected if present. In this paper we present our approach to diagnosis and treatment of iron deficiency in heart failure.

A randomized trial of intravenous and oral iron in chronic kidney disease

Although iron is commonly used to correct iron deficiency anemia (IDA) in chronic kidney disease (CKD) its effect on kidney function is unclear. To assess this, we randomly assigned patients with Stage 3 and 4 CKD and IDA to either open-label oral ferrous sulfate (69 patients to 325 mg three times daily for 8 weeks) or intravenous iron sucrose (67 patients to 200 mg every 2 weeks, total 1 gram). The primary outcome was the between group difference in slope of measured glomerular filtration rate (mGFR) change over two years. The trial was terminated early on the recommendation of an independent Data and Safety Monitoring Board based on little chance of finding differences in mGFR slopes, but a higher risk of serious adverse events in the intravenous iron treatment group. mGFR declined similarly over two years in both treatment groups (oral −3.6 mL/min/1.73m², intravenous − 4.0 mL/min/1.73m², between group difference − 0.35 mL/min/1.73m² (95% confidence interval −2.9 to 2.3). There were 36 serious cardiovascular events among 19 participants assigned to the oral iron treatment group and 55 events among 17 participants of the intravenous iron group (adjusted incidence rate ratio 2.51 (1.56−4.04). Infections resulting in hospitalizations had a significant adjusted incidence rate ratio of 2.12 (1.24−3.64). Thus, among non-dialyzed patients with CKD and IDA, intravenous iron therapy is associated with an increased risk of serious adverse events, including those from cardiovascular causes and infectious diseases.

Searching ClinicalTrials.gov and the International Clinical Trials Registry Platform to inform systematic reviews: what are the optimal search approaches?

BACKGROUND

Since 2005, International Committee of Medical Journal Editors (ICMJE) member journals have required that clinical trials be registered in publicly available trials registers before they are considered for publication.

OBJECTIVES

The research explores whether it is adequate, when searching to inform systematic reviews, to search for relevant clinical trials using only public trials registers and to identify the optimal search approaches in trials registers.

METHODS

A search was conducted in ClinicalTrials.gov and the International Clinical Trials Registry Platform (ICTRP) for research studies that had been included in eight systematic reviews. Four search approaches (highly sensitive, sensitive, precise, and highly precise) were performed using the basic and advanced interfaces in both resources.

RESULTS

On average, 84% of studies were not listed in either resource. The largest number of included studies was retrieved in ClinicalTrials.gov and ICTRP when a sensitive search approach was used in the basic interface. The use of the advanced interface maintained or improved sensitivity in 16 of 19 strategies for Clinicaltrials.gov and 8 of 18 for ICTRP. No single search approach was sensitive enough to identify all studies included in the 6 reviews.

CONCLUSIONS

Trials registers cannot yet be relied upon as the sole means to locate trials for systematic reviews. Trials registers lag behind the major bibliographic databases in terms of their search interfaces.

IMPLICATIONS

For systematic reviews, trials registers and major bibliographic databases should be searched. Trials registers should be searched using sensitive approaches, and both the registers consulted in this study should be searched.

Iron therapy for the treatment of iron deficiency in chronic heart failure: intravenous or oral?

This article considers the use and modality of iron therapy to treat iron deficiency in patients with heart failure, an aspect of care which has received relatively little attention compared with the wider topic of anaemia management. Iron deficiency affects up to 50% of heart failure patients, and is associated with poor quality of life, impaired exercise tolerance, and mortality independent of haematopoietic effects in this patient population. The European Society of Cardiology Guidelines for heart failure 2012 recommend a diagnostic work-up for iron deficiency in patients with suspected heart failure. Iron absorption from oral iron preparations is generally poor, with slow and often inefficient iron repletion; moreover, up to 60% of patients experience gastrointestinal side effects. These problems may be exacerbated in heart failure due to decreased gastrointestinal absorption and poor compliance due to pill burden. Evidence for clinical benefits using oral iron is lacking. I.v. iron sucrose has consistently been shown to improve exercise capacity, cardiac function, symptom severity, and quality of life. Similar findings were observed recently for i.v. ferric carboxymaltose in patients with systolic heart failure and impaired LVEF in the double-blind, placebo-controlled FAIR-HF and CONFIRM-HF trials. I.v. iron therapy may be better tolerated than oral iron, although confirmation in longer clinical trials is awaited. Routine diagnosis and management of iron deficiency in patients with symptomatic heart failure regardless of anaemia status is advisable, and, based on current evidence, prompt intervention using i.v. iron therapy should now be considered.

Iron therapy in anaemic adults without chronic kidney disease

BACKGROUND

Anaemia affects about a quarter of the world's population. An estimated 50% of anaemic people have anaemia due to iron deficiency.

OBJECTIVES

To assess the safety and efficacy of iron therapies for the treatment of adults with anaemia who are not pregnant or lactating and do not have chronic kidney disease.

SEARCH METHODS

We ran the search on 11 July 2013. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE (Ovid SP), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) Plus (EBSCO Host), the Institute for Scientific Information Web of Science (ISI WOS) Scientific Citation Index (SCI)-EXPANDED (1970) and Conference Proceedings Citation Index (CPCI)-Science (1990) and Clinicaltrials.gov; we also screened reference lists. An updated search was run on 24 November 2014 but the results have not yet been incorporated into the review.

SELECTION CRITERIA

Two review authors independently selected references for further assessment by going through all titles and abstracts. Further selection was based on review of full-text articles for selected references.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted study data. We calculated the risk ratio (RR) with 95% confidence interval (CI) for binary outcomes and the mean difference (MD) or the standardised mean difference (SMD) with 95% CI for continuous outcomes. We performed meta-analysis when possible, when I(2) was less than or equal to 80% using a fixed-effect or random-effects model, using Review Manager software. The range of point estimates for individual studies is presented when I(2) > 80%.

MAIN RESULTS

We included in this systematic review 4745 participants who were randomly assigned in 21 trials. Trials were conducted in a wide variety of clinical settings. Most trials included participants with mild to moderate anaemia and excluded participants who were allergic to iron therapy. All trials were at high risk of bias for one or more domains. We compared both oral iron and parenteral iron versus inactive controls and compared different iron preparations.The comparison between oral iron and inactive control revealed no evidence of clinical benefit in terms of mortality (RR 1.05, 95% CI 0.68 to 1.61; four studies, N = 659; very low-quality evidence). The point estimate of the mean difference in haemoglobin levels in individual studies ranged from 0.3 to 3.1 g/dL higher in the oral iron group than in the inactive control group. The proportion of participants who required blood transfusion was lower with oral iron than with inactive control (RR 0.74, 95% CI 0.55 to 0.99; three studies, N = 546; very low-quality evidence). Evidence was inadequate for determination of the effect of parenteral iron on mortality versus oral iron (RR 1.49, 95% CI 0.56 to 3.94; 10 studies, N = 2141; very low-quality evidence) or inactive control (RR 1.04, 95% CI 0.63 to 1.69; six studies, N = 1009; very low-quality evidence). Haemoglobin levels were higher with parenteral iron than with oral iron (MD -0.50 g/dL, 95% CI -0.73 to -0.27; six studies, N = 769; very low-quality evidence). The point estimate of the mean difference in haemoglobin levels in individual studies ranged between 0.3 and 3.0 g/dL higher in the parenteral iron group than in the inactive control group. Differences in the proportion of participants requiring blood transfusion between parenteral iron and oral iron groups (RR 0.61, 95% CI 0.24 to 1.58; two studies, N = 371; very low-quality evidence) or between parenteral iron groups and inactive controls (RR 0.84, 95% CI 0.66 to 1.06; eight studies, N = 1315; very low-quality evidence) were imprecise. Average blood volume transfused was less in the parenteral iron group than in the oral iron group (MD -0.54 units, 95% CI -0.96 to -0.12; very low-quality evidence) based on one study involving 44 people. Differences between therapies in quality of life or in the proportion of participants with serious adverse events were imprecise (very low-quality evidence). No trials reported severe allergic reactions due to parenteral iron, suggesting that these are rare. Adverse effects related to oral iron treatment included nausea, diarrhoea and constipation; most were mild.Comparisons of one iron preparation over another for mortality, haemoglobin or serious adverse events were imprecise. No information was available on quality of life. Thus, little evidence was found to support the use of one preparation or regimen over another.Subgroup analyses did not reveal consistent results; therefore we were unable to determine whether iron is useful in specific clinical situations, or whether iron therapy might be useful for people who are receiving erythropoietin.

AUTHORS' CONCLUSIONS

• Very low-quality evidence suggests that oral iron might decrease the proportion of people who require blood transfusion, and no evidence indicates that it decreases mortality. Oral iron might be useful in adults who can tolerate the adverse events, which are usually mild.• Very low-quality evidence suggests that intravenous iron results in a modest increase in haemoglobin levels compared with oral iron or inactive control without clinical benefit.• No evidence can be found to show any advantage of one iron preparation or regimen over another.• Additional randomised controlled trials with low risk of bias and powered to measure clinically useful outcomes such as mortality, quality of life and blood transfusion requirements are needed.

Hepcidin-25, mean corpuscular volume, and ferritin as predictors of response to oral iron supplementation in hemodialysis patients

The benefit of oral iron therapy (OIT) and factors predictive of OIT response are not established in hemodialysis (HD) patients with iron deficiency anemia (IDA). We examined the values of hepcidin-25, mean corpuscular volume (MCV), and ferritin as predictors of OIT response. Oral ferrous fumarate (50 mg/day, 8 weeks) was given to 51 HD patients with IDA (hemoglobin (Hb) < 12 g/dL, ferritin < 100 ng/mL) treated with an erythropoietin activator. Sixteen patients were responders (improvement of Hb (ΔHb) ≥ 2 g/dL) and 35 were non-responders (ΔHb < 2g/dL). Baseline Hb, MCV, serum hepcidin-25, ferritin, iron parameters, and C-reactive protein (CRP) before and ΔHb after OIT were compared between groups. Hepcidin-25, MCV, ferritin, and transferrin saturation were lower in the responders than in the non-responders. Hepcidin-25 positively correlated with ferritin. Hepcidin-25, MCV, and ferritin positively correlated with baseline Hb and negatively correlated with ΔHb. Despite normal CRP levels in all patients, CRP correlated positively with hepcidin-25 and ferritin. Stepwise multiple linear regression analysis and receiver operating characteristics curve analysis revealed that hepcidin-25, MCV, and ferritin could predict OIT response. We conclude that hepcidin-25, MCV, and ferritin could be useful markers of iron storage status and may help predict OIT response in HD patients.

FIND-CKD: a randomized trial of intravenous ferric carboxymaltose versus oral iron in patients with chronic kidney disease and iron deficiency anaemia

BACKGROUND

The optimal iron therapy regimen in patients with non-dialysis-dependent chronic kidney disease (CKD) is unknown.

METHODS

Ferinject® assessment in patients with Iron deficiency anaemia and Non-Dialysis-dependent Chronic Kidney Disease (FIND-CKD) was a 56-week, open-label, multicentre, prospective and randomized study of 626 patients with non-dialysis-dependent CKD, anaemia and iron deficiency not receiving erythropoiesis-stimulating agents (ESAs). Patients were randomized (1:1:2) to intravenous (IV) ferric carboxymaltose (FCM), targeting a higher (400-600 µg/L) or lower (100-200 µg/L) ferritin or oral iron therapy. The primary end point was time to initiation of other anaemia management (ESA, other iron therapy or blood transfusion) or haemoglobin (Hb) trigger of two consecutive values <10 g/dL during Weeks 8-52.

RESULTS

The primary end point occurred in 36 patients (23.5%), 49 patients (32.2%) and 98 patients (31.8%) in the high-ferritin FCM, low-ferritin FCM and oral iron groups, respectively [hazard ratio (HR): 0.65; 95% confidence interval (CI): 0.44-0.95; P = 0.026 for high-ferritin FCM versus oral iron]. The increase in Hb was greater with high-ferritin FCM versus oral iron (P = 0.014) and a greater proportion of patients achieved an Hb increase ≥1 g/dL with high-ferritin FCM versus oral iron (HR: 2.04; 95% CI: 1.52-2.72; P < 0.001). Rates of adverse events and serious adverse events were similar in all groups.

CONCLUSIONS

Compared with oral iron, IV FCM targeting a ferritin of 400-600 µg/L quickly reached and maintained Hb level, and delayed and/or reduced the need for other anaemia management including ESAs. Within the limitations of this trial, no renal toxicity was observed, with no difference in cardiovascular or infectious events.

CLINICALTRIALSGOV NUMBER

NCT00994318.

Safety and effectiveness of ferumoxytol in hemodialysis patients at 3 dialysis chains in the United States over a 12-month period

BACKGROUND

Intravenous (IV) iron is the treatment of choice for iron-deficiency anemia (IDA) in patients with dialysis-dependent chronic kidney disease (DD-CKD). However, IV iron products have been associated with serious adverse events (SAEs), including anaphylactoid reactions. Ferumoxytol is an IV iron preparation that can be injected over a short period of time. Although randomized clinical trials support ferumoxytol's efficacy and safety, additional insights may be drawn from the acquisition of long-term, repeat dosing efficacy and safety data in a real-world setting.

OBJECTIVE

The goal of this study was to characterize the effectiveness and safety profile of ferumoxytol as administered to adult DD-CKD patients with IDA in a real-world setting. The ability of ferumoxytol to maintain hemoglobin (Hb), transferrin saturation (TSAT), and ferritin treatment targets established by the 2006 Kidney Disease Outcomes Quality Initiative guidelines was determined in 3 medium-sized US-based dialysis chains.

METHODS

This retrospective, observational study was conducted to examine laboratory and dosing data for all patients who received any dose of ferumoxytol at 3 US-based dialysis chains over a 12-month period. Investigators and/or physicians from each of the chains also made independent determinations regarding the seriousness of any adverse event (AE). Special attention was paid to the incidence and types of AEs and SAEs that were potentially associated with ferumoxytol.

RESULTS

Over the 12-month observation period, 8666 patients (mean [SD] age in chains A, B and C, 63.9 [14.8], 63.9 [14.9] and 63.6 [15.1], respectively), were treated with 33,358 doses of ferumoxytol across the 3 chains. Treatment with ferumoxytol corresponded to an increased mean monthly Hb level relative to baseline (0.13-0.69 g/dL) and led to an increase in the proportion of patients maintained within the target Hb range of 10 to 12 g/dL (61%-72%). Ferumoxytol was also associated with increases in TSAT and ferritin that stabilized throughout the observation period. Incidence of AEs was similar across the 3 chains; between 0.07% and 1.77% of all patients treated at each chain experienced an AE associated with ferumoxytol administration. SAEs were reported in 0.2% of patients. The most common AEs reported (≥6 patients) were nausea (0.37% of patients), pruritus (0.29%), vomiting (0.25%), hypotension (0.21%), and dyspnea (0.20%). Two patients (0.02%) experienced anaphylactoid reactions. The AE profile of ferumoxytol remained consistent with that reported from controlled clinical trials.

CONCLUSIONS

These long-term data, which include repeat dosing in a large number of DD-CKD patients with IDA in a real-world setting, confirm the effectiveness of ferumoxytol in increasing and maintaining Hb levels within the target range and with favorable assessments of long-term safety.