Iron management in chronic kidney disease: conclusions from a “Kidney Disease: Improving Global Outcomes” (KDIGO) Controversies Conference

Factors associated with hepcidin-25 levels in maintenance hemodialysis patients

This study aimed to investigate the factors that are independently associated with hepcidin-25 and its relationship with doses of erythropoiesis-stimulating agents (ESAs) and intravenous iron in stable maintenance hemodialysis patients (smHD) stratified by ESAs administration. In 103 adult smHD (ESAs therapy (N = 64) and ESAs-free (N = 39)), median values of biologically active hepcidin-25 (chemiluminescent direct ELISA assay) and ferritin levels were significantly higher whereas red blood cell count, hemoglobin, and hematocrit values were lower in ESAs therapy compared to ESAs-free group (P < .001, for all). Our results suggest that ESAs-independent smHD exhibit supposedly normal hepcidin-25 levels and preserved iron homeostasis, with a lower degree of anemia. The results of our multivariable model indicate that hepcidin-25 levels are independently and positively associated with iron stores and inflammation, and inversely with active erythropoiesis, regardless of ESAs administration. Maintenance ESAs and the intravenous iron dose were not related to hepcidin-25 levels.

Burden of Anemia in Chronic Kidney Disease: Beyond Erythropoietin

Anemia is a frequent comorbidity of chronic kidney disease (CKD) and is associated with a considerable burden because of decreased patient health-related quality of life and increased healthcare resource utilization. Based on observational data, anemia is associated with an increased risk of CKD progression, cardiovascular events, and all-cause mortality. The current standard of care includes oral or intravenous iron supplementation, erythropoiesis-stimulating agents, and red blood cell transfusion. However, each of these therapies has its own set of population-specific patient concerns, including increased risk of cardiovascular disease, thrombosis, and mortality. Patients receiving dialysis or those who have concurrent diabetes or high blood pressure may be at greater risk of developing these complications. In particular, treatment with high doses of erythropoiesis-stimulating agents has been associated with increased rates of hospitalization, cardiovascular events, and mortality. Resistance to erythropoiesis-stimulating agents remains a therapeutic challenge in a subset of patients. Hypoxia-inducible factor transcription factors, which regulate several genes involved in erythropoiesis and iron metabolism, can be stabilized by a new class of drugs that act as inhibitors of hypoxia-inducible factor prolyl-hydroxylase enzymes to promote erythropoiesis and elevate hemoglobin levels. Here, we review the burden of anemia of chronic kidney disease, the shortcomings of current standard of care, and the potential practical advantages of hypoxia-inducible factor prolyl-hydroxylase inhibitors in the treatment of patients with anemia of CKD.

Plasma Protein Carbonyls as Biomarkers of Oxidative Stress in Chronic Kidney Disease, Dialysis, and Transplantation

Accumulating evidence indicates that oxidative stress plays a role in the pathophysiology of chronic kidney disease (CKD) and its progression; during renal replacement therapy, oxidative stress-derived oxidative damage also contributes to the development of CKD systemic complications, such as cardiovascular disease, hypertension, atherosclerosis, inflammation, anaemia, and impaired host defence. The main mechanism underlying these events is the retention of uremic toxins, which act as a substrate for oxidative processes and elicit the activation of inflammatory pathways targeting endothelial and immune cells. Due to the growing worldwide spread of CKD, there is an overwhelming need to find oxidative damage biomarkers that are easy to measure in biological fluids of subjects with CKD and patients undergoing renal replacement therapy (haemodialysis, peritoneal dialysis, and kidney transplantation), in order to overcome limitations of invasive monitoring of CKD progression. Several studies investigated biomarkers of protein oxidative damage in CKD, including plasma protein carbonyls (PCO), the most frequently used biomarker of protein damage. This review provides an up-to-date overview on advances concerning the correlation between plasma protein carbonylation in CKD progression (from stage 1 to stage 5) and the possibility that haemodialysis, peritoneal dialysis, and kidney transplantation improve plasma PCO levels. Despite the fact that the role of plasma PCO in CKD is often underestimated in clinical practice, emerging evidence highlights that plasma PCO can serve as good biomarkers of oxidative stress in CKD and substitutive therapies. Whether plasma PCO levels merely serve as biomarkers of CKD-related oxidative stress or whether they are associated with the pathogenesis of CKD complications deserves further evaluation.

SIRT3 Deficiency Sensitizes Angiotensin-II-Induced Renal Fibrosis

Background: Sirtuin 3 (SIRT3) has a crucial role in the cardiovascular diseases. Our previous study revealed that SIRT3 knockout (SIRT3KO) promoted cardiac pericyte–fibroblast transition. In this study, we investigated the involvement of pericyte and iron in angiotensin II (Ang-II)-mediated renal fibrosis in the SIRT3KO mice. Methods and Results: NG2-DsRed mice and NG2-DsRed-SIRT3 knockout (SIRT3KO) mice were infused with saline or Ang-II (1000 ng/kg/min) for 4 weeks. Renal fibrosis, iron content and reactive oxygen species (ROS) were measured. Masson’s trichrome staining showed that SIRT3KO enhanced Ang-II-induced renal fibrosis. Immunostaining showed that Ang-II treatment increased the number of NG2-DsRed+ cells in the kidney, and SIRT3KO further enhanced NG2-DsRed+ cells. Moreover, SIRT3KO promoted pericyte differentiation into fibroblasts as evidenced by co-staining NG2-DsRed/FSP-1. Furthermore, DsRed/FSP-1+ and DsRed/transforming growth factor-β1 (TGF-β1)+ fibroblasts were elevated by SIRT3KO after Ang-II infusion. Ang-II-induced collagen I and TGF-β1 expression was also enhanced in the SIRT3KO mice. SIRT3KO significantly exacerbated Ang-II-induced iron accumulation. This was accompanied by an increase in acetyl-p53, HO-1 and FPN expression. Further, SIRT3KO sensitized Ang-II-induced upregulation of p47phox and gp91phox together with increased ROS formation in the kidney. Conclusion: Our study suggests that SIRT3 deficiency sensitized Ang-II-induced renal fibrosis by the mechanisms involved in promoting differentiation of pericytes into fibroblasts, exacerbating iron overload and accelerating NADPH oxidase-derived ROS formation.

Impact of immediate post-transplant parenteral iron therapy on the prevalence of anemia and short-term allograft function in a cohort of pediatric and adolescent renal transplant recipients

Anemia is common but under-diagnosed and often inadequately treated in KTX recipients. ID is the major cause of early-onset anemia. We introduced routine use of parenteral (IV) iron in patients (2-18 years) who had KTX between January 2011 and December 2015. We explored the clinical benefits of this practice by comparing the iron-treated subjects [TX] with historical controls who had KTX between 2005 and 2010. The prevalence of anemia at 6 months (early-onset) for the cohort (both the study group and controls) was 55% and for anemia at 12 months (late-onset) was 60%. Although cause-effect relationship may not be proven in a retrospective study design, there was a significant greater frequency of ID and anemia at 3 (P < .02) and 6 months (P < .04), and a reduced allograft function (eGFR < 60 mL/min/1.73 m² ) at 12 (P = .03) and 24 months (P = .04) of KTX in the control arm. Furthermore, a greater proportion of the control arm required either ESA (P = .03) or blood transfusion (P = .04) as a rescue treatment for moderate-to-severe anemia. In conclusion, routine parenteral iron treatment was associated with a lower prevalence of early- and late-onset anemia, and a lower requirement for either ESA rescue or blood transfusion.

Management of Anemia in Nondialysis Chronic Kidney Disease: Current Recommendations, Real-World Practice, and Patient Perspectives

In nondialysis CKD (ND-CKD), anemia is a multifactorial and complex condition in which several dysfunctions dynamically contribute to a reduction in circulating hemoglobin (Hb) levels in red blood cells. Anemia is common in CKD and represents an important and modifiable risk factor for poor clinical outcomes. Importantly, symptoms related to anemia, including reduced physical functioning and fatigue, have been identified as high priorities by patients with CKD. The current management of anemia in ND-CKD (i.e., parameters to initiate treatment, Hb and iron indexes targets, choice of therapies, and effect of treatment on clinical and patient-reported outcomes) remains controversial. In this review article, we explore the epidemiology of anemia in ND-CKD and revise current recommendations and controversies in its management. Exploring data from real-world clinical practices, particularly from the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps), we highlight the current challenges to translating current recommendations to clinical practice, providing patients' perspectives of anemia and how it affects their quality of life. Finally, we summarize recent advances in the field of anemia that may change the way this condition will be managed in the future.

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.

Carbonyl iron and iron dextran therapies cause adverse effects on bone health in juveniles with chronic kidney disease

Anemia is a frequent complication of chronic kidney disease (CKD), related in part to the disruption of iron metabolism. Iron therapy is very common in children with CKD and excess iron has been shown to induce bone loss in non-CKD settings, but the impact of iron on bone health in CKD remains poorly understood. Here, we evaluated the effect of oral and parenteral iron therapy on bone transcriptome, bone histology and morphometry in two mouse models of juvenile CKD (adenine-induced and 5/6-nephrectomy). Both modalities of iron therapy effectively improved anemia in the mice with CKD, and lowered bone Fgf23 expression. At the same time, iron therapy suppressed genes implicated in bone formation and resulted in the loss of cortical and trabecular bone in the mice with CKD. Bone resorption was activated in untreated CKD, but iron therapy had no additional effect on this. Furthermore, we assessed the relationship between biomarkers of bone turnover and iron status in a cohort of children with CKD. Children treated with iron had lower levels of circulating biomarkers of bone formation (bone-specific alkaline phosphatase and the amino-terminal propeptide of type 1 procollagen), as well as fewer circulating osteoblast precursors, compared to children not treated with iron. These differences were independent of age, sex, and glomerular filtration rate. Thus, iron therapy adversely affected bone health in juvenile mice with CKD and was associated with low levels of bone formation biomarkers in children with CKD.

Clinical data for intravenous iron - debunking the hype around hypersensitivity

BACKGROUND

Reluctance to use intravenous (IV) iron for the treatment of iron deficiency continues due to a perceived high risk of severe hypersensitivity reactions (HSRs). Additionally, it has been hypothesized that 'dextran-derived' IV iron products (e.g., ferumoxytol [FER] and ferric derisomaltose/iron isomaltoside 1000 [FDI]) have a higher risk of severe HSRs than 'non-dextran-derived' products (e.g., ferric carboxymaltose [FCM] and iron sucrose [IS]). In the present analysis, HSR data from head-to-head randomized controlled trials (RCTs) with IV iron products were evaluated to determine if differences in safety signals are present among these IV iron formulations.

STUDY DESIGN AND METHODS

Reported serious or moderate-to-severe HSR incidence data from five RCTs (FIRM; FERWON-NEPHRO/-IDA; PHOSPHARE-IDA04/-IDA05) were used to calculate risk differences with 95% confidence intervals (CIs) for FER, FCM, FDI, and IS. The rates and risk differences for these HSRs were compared.

RESULTS

The analysis included data for 5247 patients: FER (n = 997), FCM (n = 1117), FDI (n = 2133) and IS (n = 1000). Overall rates of serious or moderate to severe HSRs were low (0.2%-1.7%). The risk differences (95% CIs) showed small differences between the IV iron formulations: FER versus FCM, -0.1 (-0.8 to 0.6); FDI versus IS, 0.1 (-0.3 to 0.5); FDI versus FCM, -0.9 (-3.7 to 1.9).

CONCLUSION

RCT evidence confirms a low risk of serious or moderate to severe HSRs with newer IV iron formulations and no significant differences among existing commercially available products. Thus, RCT data show that the supposed classification of dextran-derived versus non-dextran-derived IV iron products has no clinical relevance.

The changing landscape of iron deficiency

Iron deficiency (ID) with or without anemia is common worldwide. ID is a broad definition encompassing decreased total body iron (absolute deficiency) as well as reduced iron supply to erythropoietic and/or other organs with preserved stores (functional iron deficiency, FID), as it occurs in inflammation. Increased iron needs unbalanced by iron supply, low iron intake, reduced absorption and chronic blood loss, often in combination, are the main causes of absolute ID, easily diagnosed by low ferritin levels. In all these cases hepcidin synthesis is repressed, while in FID is augmented by inflammatory cytokines, causing iron sequestration in stores. Because of increased ferritin levels diagnosis of ID in the latter condition may be tricky: global clinical evaluation, accepted threshold of iron tests together with response to iron treatment may be of help. Search and removal of the responsible cause(s) is as important as diagnosing ID or FID. The response to oral iron treatment is suboptimal when hepcidin levels are high. Future research is needed to establish/validate markers for improved diagnosis of complex cases and to test the therapeutic value of drugs under development aimed at interfering with the altered iron trafficking.

Iron Sucrose: A Wealth of Experience in Treating Iron Deficiency

Iron deficiency and iron-deficiency anemia are associated with increased morbidity and mortality in a wide range of conditions. In many patient populations, this can be treated effectively with oral iron supplementation; but in patients who are unable to take or who do not respond to oral iron therapy, intravenous iron administration is recommended. Furthermore, in certain conditions, such as end-stage kidney disease, chronic heart failure, and inflammatory bowel disease, intravenous iron administration has become first-line treatment. One of the first available intravenous iron preparations is iron sucrose (Venofer®), a nanomedicine that has been used clinically since 1949. Treatment with iron sucrose is particularly beneficial owing to its ability to rapidly increase hemoglobin, ferritin, and transferrin saturation levels, with an acceptable safety profile. Recently, important new data relating to the use of iron sucrose, including the findings from the landmark PIVOTAL trial in patients with end-stage kidney disease, have been reported. Several years ago, a number of iron sucrose similars became available, although there have been concerns about the clinical appropriateness of substituting the original iron sucrose with an iron sucrose similar because of differences in efficacy and safety. This is a result of the complex and unique physicochemical properties of nanomedicines such as iron sucrose, which make copying the molecule difficult and problematic. In this review, we summarize the evidence accumulated during 70 years of clinical experience with iron sucrose in terms of efficacy, safety, and cost-effectiveness.

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.

Intravenous Iron Dosing and Infection Risk in Patients on Hemodialysis: A Prespecified Secondary Analysis of the PIVOTAL Trial

BACKGROUND

Experimental and observational studies have raised concerns that giving intravenous (IV) iron to patients, such as individuals receiving maintenance hemodialysis, might increase the risk of infections. The Proactive IV Iron Therapy in Haemodialysis Patients (PIVOTAL) trial randomized 2141 patients undergoing maintenance hemodialysis for ESKD to a high-dose or a low-dose IV iron regimen, with a primary composite outcome of all-cause death, heart attack, stroke, or hospitalization for heart failure. Comparison of infection rates between the two groups was a prespecified secondary analysis.

METHODS

Secondary end points included any infection, hospitalization for infection, and death from infection; we calculated cumulative event rates for these end points. We also interrogated the interaction between iron dose and vascular access (fistula versus catheter).

RESULTS

We found no significant difference between the high-dose IV iron group compared with the lose-dose group in event rates for all infections (46.5% versus 45.5%, respectively, which represented incidences of 63.3 versus 69.4 per 100 patient years, respectively); rates of hospitalization for infection (29.6% versus 29.3%, respectively) also did not differ. We did find a significant association between risk of a first cardiovascular event and any infection in the previous 30 days. Compared with patients undergoing dialysis with an arteriovenous fistula, those doing so via a catheter had a higher incidence of having any infection, hospitalization for infection, or fatal infection, but IV iron dosing had no effect on these outcomes.

CONCLUSIONS

The high-dose and low-dose IV iron groups exhibited identical infection rates. Risk of a first cardiovascular event strongly associated with a recent infection.

Iron Administration, Infection, and Anemia Management in CKD: Untangling the Effects of Intravenous Iron Therapy on Immunity and Infection Risk

Patients with chronic kidney disease (CKD) are at increased risk for infection, attributable to immune dysfunction, increased exposure to infectious agents, loss of cutaneous barriers, comorbid conditions, and treatment-related factors (eg, hemodialysis and immunosuppressant therapy). Because iron plays a vital role in pathogen reproduction and host immunity, it is biologically plausible that intravenous iron therapy and/or iron deficiency influence infection risk in CKD. Available data from preclinical experiments, observational studies, and randomized controlled trials are summarized to explore the interplay between intravenous iron and infection risk among patients with CKD, particularly those receiving maintenance hemodialysis. The current evidence base, including data from a recent randomized controlled trial, suggests that proactive judicious use of intravenous iron (in a manner that minimizes the accumulation of non-transferrin-bound iron) beneficially replaces iron stores while avoiding a clinically relevant effect on infection risk. In the absence of an urgent clinical need, intravenous iron therapy should be avoided in patients with active infection. Although serum ferritin concentration and transferrin saturation can help guide clinical decision making about intravenous iron therapy, definition of an optimal iron status and its precise determination in individual patients remain clinically challenging in CKD and warrant additional study.

Factors influencing safety and efficacy of intravenous iron-carbohydrate nanomedicines: From production to clinical practice

Iron deficiency is an important subclinical disease affecting over one billion people worldwide. A growing body of clinical records supports the use of intravenous iron-carbohydrate complexes for patients where iron replenishment is necessary and oral iron supplements are either ineffective or cannot be tolerated by the gastrointestinal tract. A critical characteristic of iron-carbohydrate drugs is the complexity of their core-shell structure, which has led to differences in the efficacy and safety of various iron formulations. This review describes parameters influencing the safety and effectiveness of iron-carbohydrate complexes during production, storage, handling, and clinical application. We summarized the physicochemical and biological assessments of commercially available iron carbohydrate nanomedicines to provide an overview of publicly available data. Further, we reviewed studies that described how subtle differences in the manufacturing process of iron-carbohydrate complexes can impact on the physicochemical, biological, and clinical outcomes of original product versus their intended copies or so-called iron "similar" products.

Secondary hemosiderosis presented by porphyria cutanea tarda in a kidney dialysis patient: A case report

A 68-year-old woman with chronic kidney disease receiving dialysis and iron supplementation presented to our hospital with painful blisters, fragile skin, and changes to skin pigmentation on the dorsal side of both upper and lower limbs. Skin biopsy findings and an increase in urine porphyrins confirmed the diagnosis of porphyria cutanea tarda. Upon examination, extremely high serum ferritin levels (6000 µg/L) suggested iron overload. Oral iron supplementation was immediately discontinued, and the patient received treatment with the iron chelators deferoxamine, 10 mg/kg/day intravenously for 4 days, and deferasirox, 540 mg/day orally. After a 4-month follow-up, ferritin levels were normal (97.7 µg/L) and the cutaneous manifestations of porphyria cutanea tarda had improved. Complete remission has been maintained for the last 2 years, and the patient’s liver and heart function are normal. This case of porphyria cutanea tarda caused by secondary hemosiderosis highlights the potential toxicity of iron accumulation as a result of excessive iron supplementation. Although not approved for the treatment of patients on hemodialysis, we report the efficacy of deferasirox without any adverse effects in this case. We also stress the importance of the close monitoring of serum iron levels in kidney dialysis—and indeed all iron-supplemented—patients to avoid potential hepatic, cardiac, and endocrine damage.

Iron deficiency anaemia revisited

Iron deficiency anaemia is a global health concern affecting children, women and the elderly, whilst also being a common comorbidity in multiple medical conditions. The aetiology is variable and attributed to several risk factors decreasing iron intake and absorption or increasing demand and loss, with multiple aetiologies often coexisting in an individual patient. Although presenting symptoms may be nonspecific, there is emerging evidence on the detrimental effects of iron deficiency anaemia on clinical outcomes across several medical conditions. Increased awareness about the consequences and prevalence of iron deficiency anaemia can aid early detection and management. Diagnosis can be easily made by measurement of haemoglobin and serum ferritin levels, whilst in chronic inflammatory conditions, diagnosis may be more challenging and necessitates consideration of higher serum ferritin thresholds and evaluation of transferrin saturation. Oral and intravenous formulations of iron supplementation are available, and several patient and disease-related factors need to be considered before management decisions are made. This review provides recent updates and guidance on the diagnosis and management of iron deficiency anaemia in multiple clinical settings.

Treatment of Renal Anemia with Roxadustat: Advantages and Achievement

Background

Although renal anemia has attracted widespread attention, a large proportion of chronic kidney disease (CKD) patients with anemia still do not meet the hemoglobin (Hb) targets. The discovery of prolyl hydroxylase domain (PHD) enzymes as regulators of hypoxia-inducible factor (HIF)-dependent erythropoiesis has led to the development of novel therapeutic agents for renal anemia. Roxadustat, the first small-molecule HIF-PHD inhibitor, has completed the phase 3 trials. There are currently more than 15 phase 3 clinical trials worldwide assessing the efficacy and safety of roxadustat in CKD patients with anemia. This review will summarize recent findings of roxadustat in the treatment of renal anemia.

Summary

Although the administration of erythropoiesis-stimulating agents (ESAs) and iron supplementation are a well-established and highly effective therapeutic approach for renal anemia, there are several safety concerns. Current findings from phase 2 and 3 trials suggest that roxadustat is clinically effective and well tolerated. On the one hand, roxadustat could increase endogenous erythropoietin (EPO) levels within or near physiological range in a titratable manner by inducing HIF pathway activation transiently. On the other hand, roxadustat also improves iron metabolism by decreasing serum hepcidin and increasing intestinal iron absorption, which is beneficial to functional iron deficiency and absolute iron deficiency. More importantly, the erythropoietic response of roxadustat is independent of baseline inflammatory state of CKD patients. Thus, the discovery of roxadustat will revolutionize the treatment strategy for renal anemia.

Key Messages

Roxadustat is an emerging and promising therapeutic approach against anemia in CKD patients, which differs from those of conventional ESAs. Roxadustat corrects anemia of CKD patients through multiple pathways, beyond elevating EPO levels within physiological range, and also by handling iron metabolism (particularly decreasing the hepcidin levels). Furthermore, the Hb response of roxadustat is independent of the inflammatory microenvironment.

Safety of Intravenous Iron - Cosmofer and Monofer Therapy in Peritoneal Dialysis and Non-Dialysis-Dependent Chronic Kidney Disease Patients

Safety of parenteral iron therapy is critical and has been demonstrated in several studies, but concerns persist on safety. We performed a retrospective single-center study investigating the safety and efficacy of parenteral iron administration using 2 iron preparations-Monofer and Cosmofer (Pharmacosmos A/S, Holbaek, Denmark)-in patients with chronic kidney disease (CKD), on peritoneal dialysis (PD) and non-dialysis. A database of CKD patients receiving intravenous (IV) iron was analyzed. Side effects were recorded during infusion, post-infusion, and after 48 hours. In a population of CKD patients (non-dialysis and PD), IV iron is safe with few major adverse effects for these 2 IV iron preparations studied with similar dosing schedules. These data provide reassurance on the relative short-term safety of IV iron preparations regarding acute infusion-related hypersensitivity reactions.

Erythropoietin attenuates vascular calcification by inhibiting endoplasmic reticulum stress in rats with chronic kidney disease

Previous studies suggested that endoplasmic reticulum (ER) stress induced-apoptosis promoted vascular calcification (VC). Interestingly, erythropoietin (EPO), an endogenous glycoprotein, exerts multiple tissue protective effects by inhibiting ER stress and apoptosis. We investigated the role and potential mechanism of EPO on VC in chronic kidney disease (CKD) rats and cultured vascular smooth muscle cells (VSMCs). The calcification model was established by subtotal nephrectomy in vivo or phosphate overload in vitro. The protein level of EPO receptor (EPOR) was increased in the calcified aortas of CKD rats. EPO prevented the reduction of VSMC phenotypic markers, and reversed the increased calcium content and calcium salt deposition in the aortas of CKD rats and cultured calcified VSMCs. The protein levels of activating transcription factor 4 (ATF4) and glucose-regulated protein 94 (GRP94) were upregulated in aortas and VSMCs under calcifying conditions, indicating ER stress activation. EPO treatment of CKD rats or calcified VSMCs downregulated the protein levels of ATF4 and GRP94. Furthermore, ER stress-mediated apoptosis, determined by the protein levels of CCAAT⁄enhancer-binding protein-homologous protein and cleaved caspase 12, was increased in tunicamycin or calcification media-treated VSMCs, but the increased effect was reversed in EPO-treated groups. The increased apoptotic cells in calcified VSMCs, as indicated by Hoechst staining and flow cytometry, were downregulated by the co-administration of EPO or 4-phenyl butyric acid. In conclusion, EPO might attenuate VC by inhibiting ER stress mediated apoptosis through EPOR signaling.

Histological Scores Validate the Accuracy of Hepatic Iron Load Measured by Signal Intensity Ratio and R2* Relaxometry MRI in Dialysis Patients

Almost all haemodialysis patients are treated with parenteral iron to compensate for blood loss and to allow the full therapeutic effect of erythropoiesis-stimulating agents. Iron overload is an increasingly recognised clinical situation diagnosed by quantitative magnetic resonance imaging (MRI). MRI methods have not been fully validated in dialysis patients. We compared Deugnier’s and Turlin’s histological scoring of iron overload and Scheuer’s classification (with Perls’ stain) with three quantitative MRI methods for measuring liver iron concentration (LIC)—signal intensity ratio (SIR), R2* relaxometry, and R2* multi-peak spectral modelling (Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation (IDEAL-IQ^®)) relaxometry—in 16 haemodialysis patients in whom a liver biopsy was formally indicated for medical follow-up. LIC MRI with these three different methods was highly correlated with Deugnier’s and Turlin’s histological scoring (SIR: r = 0.8329, p = 0.0002; R2* relaxometry: r = −0.9099, p < 0.0001; R2* relaxometry (IDEAL-IQ^®): r = −0.872, p = 0.0018). Scheuer’s classification was also significantly correlated with these three MRI techniques. The positive likelihood ratio for the diagnosis of abnormal LIC by Deugnier’s histological scoring was > 62 for the three MRI methods. This study supports the accuracy of quantitative MRI methods for the non-invasive diagnosis and follow-up of iron overload in haemodialysis patients.

Multicenter Safety and Practice for Off-Label Diagnostic Use of Ferumoxytol in MRI

Background Ferumoxytol is approved for use in the treatment of iron deficiency anemia, but it can serve as an alternative to gadolinium-based contrast agents. On the basis of postmarketing surveillance data, the Food and Drug Administration issued a black box warning regarding the risks of rare but serious acute hypersensitivity reactions during fast high-dose injection (510 mg iron in 17 seconds) for therapeutic use. Whereas single-center safety data for diagnostic use have been positive, multicenter data are lacking. Purpose To report multicenter safety data for off-label diagnostic ferumoxytol use. Materials and Methods The multicenter ferumoxytol MRI registry was established as an open-label nonrandomized surveillance databank without industry involvement. Each center monitored all ferumoxytol administrations, classified adverse events (AEs) using the National Cancer Institute Common Terminology Criteria for Adverse Events (grade 1-5), and assessed the relationship of AEs to ferumoxytol administration. AEs related to or possibly related to ferumoxytol injection were considered adverse reactions. The core laboratory adjudicated the AEs and classified them with the American College of Radiology (ACR) classification. Analysis of variance was used to compare vital signs. Results Between January 2003 and October 2018, 3215 patients (median age, 58 years; range, 1 day to 96 years; 1897 male patients) received 4240 ferumoxytol injections for MRI. Ferumoxytol dose ranged from 1 to 11 mg per kilogram of body weight (≤510 mg iron; rate ≤45 mg iron/sec). There were no systematic changes in vital signs after ferumoxytol administration (P > .05). No severe, life-threatening, or fatal AEs occurred. Eighty-three (1.9%) of 4240 AEs were related or possibly related to ferumoxytol infusions (75 mild [1.8%], eight moderate [0.2%]). Thirty-one AEs were classified as allergiclike reactions using ACR criteria but were consistent with minor infusion reactions observed with parenteral iron. Conclusion Diagnostic ferumoxytol use was well tolerated, associated with no serious adverse events, and implicated in few adverse reactions. Registry results indicate a positive safety profile for ferumoxytol use in MRI. © RSNA, 2019 Online supplemental material is available for this article.

Anemia of Inflammation with An Emphasis on Chronic Kidney Disease

Iron is vital for a vast variety of cellular processes and its homeostasis is strictly controlled and regulated. Nevertheless, disorders of iron metabolism are diverse and can be caused by insufficiency, overload or iron mal-distribution in tissues. Iron deficiency (ID) progresses to iron-deficiency anemia (IDA) after iron stores are depleted. Inflammation is of diverse etiology in anemia of chronic disease (ACD). It results in serum hypoferremia and tissue hyperferritinemia, which are caused by elevated serum hepcidin levels, and this underlies the onset of functional iron-deficiency anemia. Inflammation is also inhibitory to erythropoietin function and may directly increase hepcidin level, which influences iron metabolism. Consequently, immune responses orchestrate iron metabolism, aggravate iron sequestration and, ultimately, impair the processes of erythropoiesis. Hence, functional iron-deficiency anemia is a risk factor for several ailments, disorders and diseases. Therefore, therapeutic strategies depend on the symptoms, severity, comorbidities and the associated risk factors of anemia. Oral iron supplements can be employed to treat ID and mild anemia particularly, when gastrointestinal intolerance is minimal. Intravenous (IV) iron is the option in moderate and severe anemic conditions, for patients with compromised intestinal integrity, or when oral iron is refractory. Erythropoietin (EPO) is used to treat functional iron deficiency, and blood transfusion is restricted to refractory patients or in life-threatening emergency situations. Despite these interventions, many patients remain anemic and do not respond to conventional treatment approaches. However, various novel therapies are being developed to treat persistent anemia in patients.

The multifaceted role of iron in renal health and disease

Iron is an essential element that is indispensable for life. The delicate physiological body iron balance is maintained by both systemic and cellular regulatory mechanisms. The iron-regulatory hormone hepcidin assures maintenance of adequate systemic iron levels and is regulated by circulating and stored iron levels, inflammation and erythropoiesis. The kidney has an important role in preventing iron loss from the body by means of reabsorption. Cellular iron levels are dependent on iron import, storage, utilization and export, which are mainly regulated by the iron response element-iron regulatory protein (IRE-IRP) system. In the kidney, iron transport mechanisms independent of the IRE-IRP system have been identified, suggesting additional mechanisms for iron handling in this organ. Yet, knowledge gaps on renal iron handling remain in terms of redundancy in transport mechanisms, the roles of the different tubular segments and related regulatory processes. Disturbances in cellular and systemic iron balance are recognized as causes and consequences of kidney injury. Consequently, iron metabolism has become a focus for novel therapeutic interventions for acute kidney injury and chronic kidney disease, which has fuelled interest in the molecular mechanisms of renal iron handling and renal injury, as well as the complex dynamics between systemic and local cellular iron regulation.

What do we learn about the “Anemia Module” of the French language Peritoneal Dialysis ? Interest and Results

Background: Anemia is commonly observed in patients with chronic kidney disease (CKD) as soon as the glomerular filtration rate falls below than 30 ml/min. CKD patients frequently have iron deficiency. The use of both erythropoiesis-stimulating agents (ESA) and iron therapy is the backbone of anemia management in CKD. For this reason, an adequate iron supply is mandatory to achieve the optimal therapeutic benefit of erythropoiesis stimulating agents (ESAs). Many groups agree that anemia in peritoneal dialysis (PD) patients is less severe than in hemodialysis (HD) patients and that there are important differences in treatment practices for anemia between PD and HD patients. Methods: Analysis of the Anemia module of the French Language Peritoneal Dialysis Registry (RDPLF) register from the database set up in 2005 with a study of the period 2010-2017. Results: Data from 568 patients who participated in the Anemia module were analysed during the 2010-2017 follow-up period. Their median age were 71 years, 42% were female, median dialysis vintage was 13 months, 40,5% of patients had diabetes mellitus, 74% of patients were treated with ESA, 23% were on oral iron and only 11% have received intravenous iron. In terms of biological assessment, the average hemoglobin level was close to 12 g/dl and median CRP was close to 5 mg/l. For the iron balance, ferritin reached an average level of 270 µg/l in 2013 and stabilized in 2017 at 200 µg/l. The transferrin saturation coefficient always fluctuated between 23 % and 25 % from year 2010 to year 2017. Conclusion: The results of the Anemia module of RDPLF register appear to be in line with the target values of the ERA-EDTA latest European guideline on anemia (ERBP 2013) and show the low use of intravenous iron in PD (usually as second line therapy).

Infectious complications and mortality associated with the use of IV iron therapy: a systematic review and meta-analysis

BACKGROUND

Parental iron is used to optimize hemoglobin and enhance erythropoiesis in end-stage renal disease along with erythropoietin-stimulating agents. Safety of iron has been debated extensively and there is no definite evidence whether parenteral iron increases the risk of infections and mortality. We performed this meta-analysis to evaluate the incidence of infectious complications, hospitalizations and mortality with use of parenteral iron.

METHODS

Medical electronic databases [PubMed, EMBASE, Scopus, Web of Science, and cochrane central register for controlled clinical trials (CENTRAL)] were queried for studies that investigated the association between intravenous iron administration and infection in hemodialysis patients. 24 studies (8 Randomized control trials (RCTs) and 16 observational studies) were considered for qualitative and quantitative analysis.

RESULTS

All-cause mortality Data from 6 RCTs show that high-dose IV iron conferred 17% less all-cause mortality compared to controls; however, this outcome was not statistically significant (OR = 0.83, CI [0.7, 1.01], p = 0.07). Nine observational studies were pooled under the random effects model due to significant heterogeneity (I² = 83%, p < 0.001). The overall HR showed increased risk of all-cause mortality in the high-dose group but was statistically non-significant (HR = 1.1, CI [1, 1.22], p = 0.06). Infections Four RCTs with no heterogeneity among their data (I² = 0%, p = 0.61). Under the fixed effect model, there was no difference in the infection rate between high-dose iron and control group (OR = 0.97, CI [0.82, 1.16], p = 0.77); eight observational studies with significant heterogeneity and utilizing random effects model. Summary HR showed increased yet non-significant risk of infection in the high-dose group (HR = 1.13, CI [0.99, 1.28], p = 0.07) Hospitalization 1 RCT and six observational studies provided data for the rate of all-cause hospitalization. There was marked heterogeneity among observational studies. RCT showed no significant difference between high-dose iron and controls in the rate of hospitalization (OR = 1.03, CI [0.87, 1.23], p = 0.71). Summary HR for observational data showed increased rate of hospitalization in the high-dose group; however, this effect was not statistically significant (HR = 1.11, CI [0.99, 1.24], p = 0.07). Cardiovascular events One RCT compared the rate of adverse cardiovascular events between high-dose and low-dose iron. No significant difference was observed between the two groups (22.3% vs 25.6%, p = 0.12). Six heterogeneous observational studies (I² = 65%, p < 0.001) reported on the rate of cardiovascular events. No significant difference was observed between high-dose iron and controls (HR = 1.18, CI [0.89, 1.57], p = 0.24).

CONCLUSION

High-dose parenteral iron does not seem to be associated with higher risk of infection, all-cause mortality, increased hospitalization or increased cardiovascular events on analysis of RCTs. Observational studies show increased risk for all-cause mortality, infections and hospitalizations that were not statistically significant and were associated with significant heterogeneity.

A prospective, multi-center, randomized comparison of iron isomaltoside 1000 versus iron sucrose in patients with iron deficiency anemia; the FERWON-IDA trial

Iron deficiency anemia (IDA) is prevalent, and intravenous iron, especially if given in a single dose, may result in better adherence compared with oral iron. The present trial (FERWON‐IDA) is part of the FERWON program with iron isomaltoside 1000/ferric derisomaltose (IIM), evaluating safety and efficacy of high dose IIM in IDA patients of mixed etiologies. This was a randomized, open‐label, comparative, multi‐center trial conducted in the USA. The IDA patients were randomized 2:1 to a single dose of 1000 mg IIM, or iron sucrose (IS) administered as 200 mg intravenous injections, up to five times. The co‐primary endpoints were adjudicated serious or severe hypersensitivity reactions, and change in hemoglobin from baseline to week eight. A total of 1512 patients were enrolled. The frequency of patients with serious or severe hypersensitivity reactions was 0.3% (95% confidence interval: 0.06;0.88) vs 0.4% (0.05;1.45) in the IIM and IS group, respectively. The co‐primary safety objective was met, and no risk difference was observed between groups. The co‐primary efficacy endpoint of non‐inferiority in hemoglobin change was met, and IIM led to a significantly more rapid hematological response in the first two weeks. The frequency of cardiovascular events was 0.8% and 1.2% in the IIM and IS group, respectively (P = .570). The frequency of hypophosphatemia was low in both groups. Iron isomaltoside administered as 1000 mg resulted in a more rapid and more pronounced hematological response, compared with IS, which required multiple visits. The safety profile was similar with a low frequency of hypersensitivity reactions and cardiovascular events.

Administration of Intravenous Iron Formulations Induces Complement Activation in-vivo

Background: Intravenous (IV) iron is widely used to treat anemia in chronic kidney disease patients. Previously, iron formulations were shown to induce immune activation in-vitro. The current study aimed to investigate the effect of IV iron on complement activation in-vivo, and whether this subsequently induces inflammation and/or oxidative stress. Methods: Two distinct patient groups were included: 51 non-dialysis and 32 dialysis patients. The non-dialysis group received iron sucrose or ferric carboxymaltose, based on physicians' choice. Plasma samples were collected prior to and 1 h after completion of IV iron infusion. The dialysis group received iron sucrose exclusively. Plasma samples were collected at the start and end of two consecutive hemodialysis sessions, one with and one without IV iron. Finally, plasma levels of MBL, C1q, properdin, factor D, sC5b-9, MPO, PTX3 were assessed by ELISA. Results: In the non-dialysis group, sC5b-9 levels significantly increased after IV iron by 32%, while levels of factor D and MBL significantly dropped. Subgroup analysis demonstrated that iron sucrose induced complement activation whereas ferric carboxymaltose did not. In the dialysis group, levels of sC5b-9 significantly increased by 46% during the dialysis session with IV iron, while factor D levels significantly fell. Furthermore, the relative decrease in factor D by IV iron correlated significantly with the relative increase in sC5b-9 by IV iron. MPO levels rose significantly during the dialysis session with IV iron, but not in the session without iron. Moreover, the relative increase in MPO and sC5b-9 by IV iron correlated significantly. PTX3 levels were not affected by IV iron. Conclusions: Iron sucrose but not ferric carboxymaltose, results in complement activation possibly via the lectin and alternative pathway partially mediating oxidative stress but not inflammation.

Iron Regulation by Molidustat, a Daily Oral Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitor, in Patients with Chronic Kidney Disease

BACKGROUND/AIMS

The current treatment for anemia associated with chronic kidney disease (CKD) includes the administration of erythropoiesis stimulating agents (ESAs) combined with iron supplementation. Molidustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor, has potential to treat anemia associated with CKD through increased erythropoietin production and improved iron availability. Here, we report the effect of molidustat on iron metabolism.

METHOD

Parameters of iron metabolism were monitored in three 16-week, randomized, controlled, phase 2 studies assessing the safety and efficacy of molidustat in the treatment of anemia associated with CKD in different populations: treatment-naïve and previously ESA-treated patients not on dialysis, and previously ESA-treated patients on hemodialysis. Iron supplementation was left at the discretion of the investigator.

RESULTS

In treatment-naïve patients not on dialysis, transferrin saturation (TSAT), hepcidin, ferritin, and iron concentrations decreased with molidustat, whereas total iron binding capacity (TIBC) increased. Similar results were observed in previously ESA-treated patients not on dialysis, although changes in those parameters were larger in treatment-naïve than in previously ESA-treated patients. In previously ESA-treated patients receiving hemodialysis, hepcidin concentration and TIBC remained stable with molidustat, whereas TSAT and ferritin and iron concentrations increased. Generally, similar trends were observed in secondary analyses of subgroups of patients not receiving iron supplementation.

CONCLUSIONS

Molidustat is a potential alternative to standard treatment of anemia associated with CKD, with a different mechanism of action. In patients not receiving dialysis, molidustat increases iron availability. In patients receiving hemodialysis, further investigation is required to understand fully the mechanisms underlying iron mobilization associated with molidustat.

Anemia and iron deficiency among chronic kidney disease Stages 3-5ND patients in the Chronic Kidney Disease Outcomes and Practice Patterns Study: often unmeasured, variably treated

Background

International variation in anemia assessment and management practices in chronic kidney disease (CKD) is poorly understood.

Methods

We performed a cross-sectional analysis of anemia laboratory monitoring, prevalence and management in the prospective Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps). A total of 6766 participants with CKD Stages 3a–5ND from nephrology clinics in Brazil, France, Germany and the USA were included.

Results

Among patients with anemia (hemoglobin <12 g/dL), 36–58% in Brazil, the USA and Germany had repeat hemoglobin measured and 40–61% had iron indices measured within 3 months of the index hemoglobin measurement. Anemia was more common in the USA and Brazil than in France and Germany across CKD stages. Higher ferritin and lower iron saturation (TSAT) levels were observed with lower hemoglobin levels, and higher ferritin with more advanced CKD. The proportion of anemic patients with ferritin <100 ng/mL or TSAT <20% ranged from 42% in Brazil to 53% in France and Germany, and of these patients, over 40% in Brazil, Germany and the USA, compared with 27% in France, were treated with oral or intravenous iron within 3 months after hemoglobin measurement. The proportion of patients with hemoglobin <10 g/dL treated with erythropoiesis-stimulating agents ranged from 28% in the USA to 57% in Germany.

Conclusions

Hemoglobin and iron stores are measured less frequently than per guidelines. Among all regions, there was a substantial proportion of anemic patients with iron deficiency who were not treated with iron, highlighting an area for practice improvement in CKD care.

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.

Low hemoglobin at hemodialysis initiation: an international study of anemia management and mortality in the early dialysis period

Background

Anemia at hemodialysis (HD) initiation is common. Correcting low hemoglobin (Hgb) before HD initiation may improve survival by avoiding potential harms of chronic anemia, high doses of erythropoiesis-stimulating agents (ESAs) and intravenous (IV) iron in the early HD period, and/or rapid Hgb rise.

Methods

We included 4604 incident HD patients from 21 countries in the Dialysis Outcomes and Practice Patterns Study Phases 4–5 (2009–15). Because low Hgb at HD start may reflect comorbidity or ESA hyporesponse, we restricted our analysis to the 80% of patients who achieved Hgb ≥10 g/dL 91–120 days after HD start (Month 4).

Results

About 53% of these patients had Hgb <10 g/dL in Month 1 (<30 days after HD start); they were younger with a similar comorbidity profile (versus Hgb ≥10 g/dL). Month 1 Hgb was associated with first-year HD mortality (adjusted hazard ratio for 1 g/dL higher Hgb was 0.89; 95% confidence interval: 0.81–0.97), despite minimal differences in Month 4 Hgb. Patients with lower Hgb in Month 1 received higher doses of ESA, but not IV iron, over the first 3 months of HD. Results were consistent when excluding catheter users or adjusting for IV iron and ESA dose over the first 3 months.

Conclusions

Even among patients with Hgb ≥10 g/dL 3 months later, anemia at HD initiation was common and associated with elevated mortality. A more proactive approach to anemia management in advanced chronic kidney disease (CKD) may thus improve survival on HD, though long-term prospective studies of non-dialysis CKD patients are needed.

Novel Oral Iron Therapies for Iron Deficiency Anemia in Chronic Kidney Disease

Iron deficiency anemia (IDA) is a frequent complication of chronic kidney disease (CKD) and is associated with adverse outcomes in these patients. Patients with CKD and IDA remain largely undertreated. Conventional oral iron agents are insufficiently effective due to poor absorption and cause gastrointestinal side effects; thus, novel oral iron preparations are needed. This article covers current treatment guidelines for patients with anemia and CKD and clinical trial data for iron-repletion agents currently in use, as well as for novel oral iron therapies in development. Ferric citrate, a novel oral iron-repletion agent approved for patients with non-dialysis-dependent CKD and IDA, demonstrated improvements in hemoglobin levels and iron parameters, with good tolerability in patients with non-dialysis-dependent CKD. When used as a phosphate binder, ferric citrate also improves hemoglobin and iron parameters in dialysis-dependent CKD, but additional trials are needed to evaluate its efficacy as an iron-repletion agent in this setting. Other novel oral iron preparations in development for IDA in patients with CKD include ferric maltol, which is approved in Europe and the United States for IDA in adult patients, and sucrosomial iron, which has been evaluated in IDA associated with CKD and several other clinical settings.

Heart failure in chronic kidney disease: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

The incidence and prevalence of heart failure (HF) and chronic kidney disease (CKD) are increasing, and as such a better understanding of the interface between both conditions is imperative for developing optimal strategies for their detection, prevention, diagnosis, and management. To this end, Kidney Disease: Improving Global Outcomes (KDIGO) convened an international, multidisciplinary Controversies Conference titled Heart Failure in CKD. Breakout group discussions included (i) HF with preserved ejection fraction (HFpEF) and nondialysis CKD, (ii) HF with reduced ejection fraction (HFrEF) and nondialysis CKD, (iii) HFpEF and dialysis-dependent CKD, (iv) HFrEF and dialysis-dependent CKD, and (v) HF in kidney transplant patients. The questions that formed the basis of discussions are available on the KDIGO website http://kdigo.org/conferences/heart-failure-in-ckd/, and the deliberations from the conference are summarized here.

Safety of Dynamic Intravenous Iron Administration Strategies in Hemodialysis Patients

BACKGROUND AND OBJECTIVES

Intravenous iron therapy for chronic anemia management is largely driven by dosing protocols that differ in intensity with respect to dosing approach (i.e., dose, frequency, and duration). Little is known about the safety of these protocols.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using clinical data from a large United States dialysis provider linked to health care utilization data from Medicare, we constructed a cohort of patients with ESKD aged ≥65 years who initiated and continued center-based hemodialysis for ≥90 days between 2009 and 2012, and initiated at least one of the five common intravenous iron administration strategies; ranked by intensity (the amount of iron given at moderate-to-high iron indices), the order of strategies was 3 (least intensive), 2 (less intensive), 1 (reference), 4 (more intensive), and 5 (most intensive). We estimated the effect of continuous exposure to these strategies on cumulative risks of mortality and infection-related events with dynamic Cox marginal structural models.

RESULTS

Of 13,249 eligible patients, 1320 (10%) died and 1627 (12%) had one or more infection-related events during the 4-month follow-up. The most and least commonly initiated strategy was strategy 2 and 5, respectively. Compared with the reference strategy 1, more intensive strategies (4 and 5) demonstrated a higher risk of all-cause mortality (e.g., most intensive strategy 5: 60-day risk difference: 1.3%; 95% confidence interval [95% CI], 0.8% to 2.1%; 120-day risk difference: 3.1%; 95% CI, 1.0% to 5.6%). Similarly, higher risks were observed for infection-related morbidity and mortality among more intensive strategies (e.g., strategy 5: 60-day risk difference: 1.8%; 95% CI, 1.2% to 2.6%; 120-day risk difference: 4.3%; 95% CI, 2.2% to 6.8%). Less intensive strategies (2 and 3) demonstrated lower risks of all-cause mortality and infection-related events.

CONCLUSIONS

Among dialysis patients surviving 90 days, subsequent intravenous iron administration strategies promoting more intensive iron treatment at moderate-to-high iron indices levels are associated with higher risks of mortality and infection-related events.

Ferric Carboxymaltose: A Review in Iron Deficiency

Intravenous ferric carboxymaltose (Ferinject^®; Injectafer^®) is a colloidal solution of nanoparticles which consist of a polynuclear iron (III)-(oxyhydr)oxide core stabilized by carboxymaltose and may be given as a single high-dose, 15-min infusion. This article reviews the clinical use of ferric carboxymaltose in various patient populations with iron deficiency (ID) [± anaemia] and briefly summarizes its pharmacological properties. Based on extensive experience in the clinical trial and real-world settings, ferric carboxymaltose is an effective and generally well tolerated treatment for rapidly replenishing iron stores and correcting anaemia in patients with ID (± anaemia) of various aetiologies, including patients with chronic heart failure (CHF), chronic kidney disease, inflammatory bowel disease or perioperative anaemia, and women with ID during pregnancy, postpartum or associated with heavy uterine bleeding. As it may be given as a single high-dose infusion, ferric carboxymaltose has the potential to provide cost savings from a healthpayer perspective. Thus, ferric carboxymaltose remains an important option for the treatment of ID in adults and, where approved, children aged ≥ 14 years, when oral iron preparations are ineffective or cannot be used.

Canadian expert consensus: management of hypersensitivity reactions to intravenous iron in adults

Background and Objectives

Rare but potentially life‐threatening hypersensitivity reactions can occur during the administration of intravenous iron. To provide guidance to healthcare professionals caring for adults receiving intravenous iron, a panel of 10 Canadian clinical experts developed a practical algorithm for the identification and management of hypersensitivity reactions to intravenous iron.

Materials and methods

A systematic search of PubMed to February 2018 was performed. Articles related to hypersensitivity reactions were selected for review. The algorithm was developed during a 1‐day live meeting based on the literature review and clinical expertise where evidence was lacking. The algorithm was then refined through an iterative process involving a web‐based platform and virtual meetings.

Results

The algorithm provides guidance to healthcare professionals in preparing for and administering IV iron, as well as recognizing and managing hypersensitivity reactions to intravenous iron. Considerations for re‐challenging patients who have experienced prior reactions are provided.

Conclusion

Healthcare professionals who are involved in the care of patients receiving intravenous iron should be trained to anticipate, recognize and manage hypersensitivity reactions to intravenous iron to optimize patient care.

Hepcidin as a therapeutic target for anemia and inflammation associated with chronic kidney disease

INTRODUCTION

Anemia is a common manifestation of chronic kidney disease (CKD). The pathogenesis of CKD-associated anemia is multifactorial. Our understanding of the molecular control of iron metabolism has improved dramatically because of the discovery of hepcidin and attempts to introduce new drugs to stimulate erythropoiesis or affect the hepcidin-ferroportin pathway have recently emerged. Areas covered: We examine the possible role of hepcidin in iron metabolism and regulation and the potential therapeutic options involving hepcidin and hepcidin-ferroportin axis in renal anemia treatment. We focus on therapeutic targeting of hepcidin, the hepcidin-ferroportin axis and key molecules such as anti-hepcidin antibodies, spigelmers, and anticalins. We also discuss compounds affecting the bone morphogenetic protein receptor [BMP/BMPR] complex and molecules that influence hepcidin, such as hypoxia-inducible factor 1 stabilizers. Expert opinion: Hepcidin is a key regulator of iron availability and is a potential future therapeutic target for managing anemia that is associated with CKD. There are potential risks and benefits associated with novel sophisticated therapies and there are several novel options on the horizon; however, clinical data are currently limited and need development. Inhibition of hepcidin via various pathways might be a viable adjunctive therapeutic option in other clinical situations.

Danggui Buxue Tang promotes the adhesion and migration of bone marrow stromal cells via the focal adhesion pathway in vitro

ETHNOPHARMACOLOGY RELEVANCE

Danggui Buxue Tang has been used in China to treat clinical anemia for more than 800 years. However, there is no scientific report on its effect on bone marrow stromal cells.

AIM OF THE STUDY

Here, we aimed to explore the effect of Danggui Buxue Tang on bone marrow stromal cell adhesion and migration.

MATERIALS AND METHODS

Bone marrow stromal cells were used as a model to evaluate the effect of Danggui Buxue Tang on the adhesion and migration of bone marrow stromal cells. RNA-sequencing, quantitative polymerase chain reaction, and western blotting were used to detect and confirm the expression of genes related to the focal adhesion pathway before and after drug delivery.

RESULTS

Danggui Buxue Tang significantly increased the number of bone marrow stromal cells. After 12 days of 16 mg/mL Danggui Buxue Tang treatment, bone marrow stromal cells were significantly increased (by 0.527 ± 0.008 fold; p < 0.001) as compared to the control group (0.180 ± 0.019). The effect was not due to enhanced cell proliferation, as there was no difference in the cell cycle (p > 0.05). The adhesion area of a single cell was doubled by Danggui Buxue Tang treatment (p < 0.001), and the time required for cell adhesion to a Petri dish was shortened. Thus, Danggui Buxue Tang increases the number of bone marrow stromal cells by promoting adhesion. Danggui Buxue Tang also significantly promoted bone marrow stromal cell migration (p <  0.001). Transcript analysis revealed that the focal adhesion and PI3K-Akt signaling pathways were activated. Expression analysis confirmed that the gene and protein expression of focal adhesion-related factors were upregulated.

CONCLUSION

Danggui Buxue Tangaffects bone marrow stromal cell adhesion and migration by enhancing the focal adhesion pathway in vitro, and bone marrow stromal cells are a target of DBT-regulated hematopoiesis, and the active ingredients of DBT involved in the effects require further investigation.

Misdistribution of iron and oxidative stress in chronic kidney disease

Chronic kidney disease (CKD) patients have an extremely high risk of developing cardiovascular diseases (CVD) compared to the general population. Systemic inflammation associated with oxidative stress could be an important determinant of morbidity and mortality associated with CVD. We suspected that dysregulation of iron metabolism should be considered in these patients. Anemia is prevalent in CKD patients and is often treated with erythropoiesis-stimulating agents (ESAs) and iron. In addition, iron administration sometimes causes iron overdose. Excessive iron in the cytosol and mitochondria can accelerate the formation of a highly toxic reactive oxygen species, hydroxyl radicals, which damage lipids, proteins, and DNA. In this review, we propose the following four major reasons for oxidative stress in CKD patients: 1) iron is sequestered in cells by proinflammatory cytokines and hepcidin; 2) the reduction in frataxin increases "free" iron in mitochondria; 3) the accumulation of 5-aminolevulinic acid, a heme precursor, has toxic effects on iron and mitochondrial metabolism; and 4) the elevated levels of the metabolic hormone, leptin, promote hepatic hepcidin production. Although an efficient therapy for preventing oxidative stress in these patients has not yet been well defined, we propose that ESAs for renal anemia may ameliorate these causes of oxidative stress. Further clinical trials are necessary to clarify the effectiveness of ESAs on oxidative stress in CKD patients.

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.

Hepcidin in chronic kidney disease anemia

Chronic kidney disease (CKD) is associated with several complications that worsen with progression of disease; anemia, disturbances in iron metabolism and inflammation are common features. Inflammatory response starts early, releasing pro-inflammatory cytokines, acute phase reactants and hepcidin. Hepcidin production is modulated by several factors, as hypoxia/anemia, erythropoietin and erythropoiesis products, transferrin saturation (TSAT) and liver iron levels, which are altered in CKD. Treatment of CKD anemia is based on pharmaceutical intervention, with erythropoietic stimulating agents and/or iron supplementation; however, in spite of the erythropoietic benefits, this therapy, on a regular basis, involves risks, namely iron overload. To overcome these risks, some therapeutic approaches are under study to target CKD anemia. Considering the actual alerts about risk of iron overload in dialysis patients, inhibition of hepcidin, the central key player in iron homeostasis, could be a pivotal strategy in the management of CKD anemia.