Kidney Disease: Improving Global Outcomes guidelines on anaemia management in chronic kidney disease: a European Renal Best Practice position statement

Vascular Access Thrombosis Events in Patients With Dialysis-Dependent CKD Treated With Vadadustat or Darbepoetin Alfa: The INNO2VATE Trial Program

Rationale & Objective

In the global phase 3 INNO2VATE program of patients with dialysis-dependent chronic kidney disease (DD-CKD) and CKD-related anemia (2 trials: patients new to [NCT02865850] and established on maintenance dialysis [NCT02892149]), vadadustat was noninferior to the erythropoiesis-stimulating agent darbepoetin alfa for cardiovascular safety and hemoglobin efficacy. Here, we investigated between-group differences in positively adjudicated vascular access thrombosis (VAT) events.

Study Design

Phase 3, global, open-label, randomized, active-controlled clinical trials.

Setting & Participants

A total of 3,902 patients who initiated dialysis within the past 16 weeks (incident DD-CKD trial; N = 365) or who had been treated with dialysis for >12 weeks (prevalent DD-CKD trial; N = 3,537).

Intervention

Eligible patients randomized 1:1 to vadadustat or darbepoetin alfa.

Outcomes

Positively adjudicated VAT events.

Results

In the INNO2VATE program, at baseline, 3,590 (92.0%) randomized patients were receiving hemodialysis: 2,709 (69.4%) via an arteriovenous fistula and 340 (8.7%) via an arteriovenous graft. During 6,468 patient-years (PY) of follow-up, there were 426 positively adjudicated VAT events in 266 individual patients, with 146 randomized to vadadustat and 120 randomized to darbepoetin alfa. Corresponding first VAT rates were 4.79 and 3.86 per 100 PY, respectively (rate difference, 0.94; 95% CI, -0.10 to 1.97; hazard ratio [HR], 1.27; 95% CI, 0.99-1.62). When considering first and recurrent events, VAT rates were 6.58 and 6.59 per 100 PY for the vadadustat and darbepoetin alfa groups, respectively (rate difference, -0.01; 95% CI, -1.26 to 1.24; HR, 1.00; 95% CI, 0.83-1.21).

Limitations

Trials were not specifically designed to assess VAT rates; uncertain generalizability to nontrial populations.

Conclusions

In this secondary analysis of the INNO2VATE program in patients with DD-CKD and CKD-related anemia receiving hemodialysis, first VAT rates were numerically higher among patients treated with vadadustat versus darbepoetin alfa but statistically not different. The rates of first and recurrent VAT events were similar between treatment groups.

Associations between iron markers with hemoglobin and outcomes in peritoneal dialysis patients: results from the PDTAP study

Background and hypothesis

Iron metabolism markers, such as transferrin saturation (TSAT) and ferritin, are crucial in anemia management in patients with CKD and those undergoing dialysis, yet optimal levels remain unelucidated.

Methods

We conducted a prospective multicenter cohort study using data from the nationwide Peritoneal Dialysis Telemedicine-based Management Platform (PDTAP) to analyze TSAT, ferritin, and hemoglobin (Hb) levels, and their associations with mortality in the peritoneal dialysis (PD) population.

Results

Our study included 4429 PD patients, analyzing data through restricted cubic splines and Cox regression models, adjusted for multiple confounders. Non-linear associations between Hb levels and TSAT/ferritin were observed. Hb levels increased with TSAT up to 40%, then plateaued, whereas ferritin levels increased with the decline of Hb. Further, ferritin levels above 200 ng/mL were independently linked to increased mortality risk [hazard ratio (HR) 1.207, 95% confidence interval (CI) 1.134-1.286], with this effect decreasing as high-sensitivity C-reactive protein levels rose. This risk was notably significant in patients with a history of cardiovascular disease. A ferritin/Hb ratio >2 was associated with increased risk of mortality after adjusting for demographic, nutritional factors and erythropoiesis agents (HR 1.219, 95% CI 1.144-1.299). The ferritin/Hb ratio demonstrated superior predictive ability for iron responsiveness compared with ferritin alone.

Conclusion

Serum ferritin level exceeding 200 ng/mL was indepently associated with a higher risk of martality in Chinese PD population. Monitoring the ferritin/Hb ratio may help assess the relative iron content in the body and provide reference for iron supplementation among patients undergoing PD.

Vadadustat Three Times Weekly in Patients With Anemia Due to Dialysis-Dependent CKD

RATIONALE & OBJECTIVE

Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) may offer an alternative to erythropoiesis-stimulating agents (ESAs) for the treatment of anemia in the setting of chronic kidney disease (CKD). The objective of this study was to investigate the efficacy and safety of conversion from the long-acting ESA methoxy polyethylene glycol-epoetin-ß (MPG-EPO) to the oral HIF-PHI vadadustat 3 times weekly versus maintenance therapy with MPG-EPO.

STUDY DESIGN

Phase 3b, open-label, noninferiority trial.

SETTING & PARTICIPANTS

Multicenter study in the United States in 456 adult participants with anemia and dialysis-dependent CKD.

INTERVENTION

Participants were randomized 1:1:1 to vadadustat at a starting dose of 600mg thrice weekly, vadadustat at a starting dose of 900mg thrice weekly, or MPG-EPO for up to 52 treatment weeks and 4 safety follow-up weeks after the end of treatment or early termination.

OUTCOMES

Primary and secondary efficacy end points were the mean change in hemoglobin concentration from baseline during primary (weeks 20-26) and secondary (weeks 46-52) evaluation periods, respectively. Noninferiority was specified as a lower bound of the 95% CI above -0.75g/dL for the difference in mean change in hemoglobin concentration from baseline. Other efficacy end points were the proportion of participants with hemoglobin levels within the target range and the proportions of participants requiring ESA or red blood cell transfusion rescue for anemia during the evaluation periods. Primary safety end points were any treatment-emergent and serious adverse events (AEs).

RESULTS

After combining the vadadustat groups (600mg and 900mg thrice weekly; n=304), vadadustat was noninferior to MPG-EPO (n=152) for primary (least-squares mean treatment difference, -0.33; 95% CI, -0.53 to-0.13) and secondary (-0.33; -0.56 to-0.09) efficacy end points. Mean hemoglobin concentrations were stable for all groups except for an initial slight decrease in the vadadustat 600mg group, which stabilized by week 12. ESA rescue for anemia was more frequent in the MPG-EPO group (primary evaluation period, 27.7%; secondary evaluation period, 16.2%) than in the combined vadadustat (14.2%; 7.3%) groups. Transfusion rates were low and occurred at similar rates across treatment groups (2.7% and 4.0% in the combined vadadustat and MPG-EPO groups, respectively). The incidences of any treatment-emergent and serious treatment-emergent AEs were similar across treatment groups.

LIMITATIONS

Potential errors in attribution of AEs as drug-related.

CONCLUSIONS

Three-times-weekly vadadustat was noninferior to MPG-EPO in its effect on hemoglobin levels without detectable differences in AEs.

FUNDING

Funding from a private entity (Akebia Therapeutics, Inc).

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study identifier NCT04707768.

PLAIN-LANGUAGE SUMMARY

Vadadustat, taken 3 times a week, was noninferior to methoxy polyethylene glycol-epoetin-ß (MPG-EPO) in treating anemia. Vadadustat is an oral drug used to treat anemia in people with chronic kidney disease. This study enrolled participants undergoing dialysis for kidney failure and compared the efficacy and safety of continuing to receive MPG-EPO, a long-acting injectable anemia treatment, or switching to vadadustat, taken by mouth 3 times per week for 1 year. Vadadustat was noninferior to MPG-EPO in maintaining hemoglobin levels. Hemoglobin levels remained stable across all groups, except for a slight decrease in the lower-dose vadadustat group, which stabilized with dose titration by week 12. The occurrence of new or serious side effects was similar across treatment groups.

Mean Corpuscular Volume Is Not a Reliable Predictor of Iron Deficiency in Patients With Chronic Kidney Disease: A Post-Hoc Analysis of the BRIGHTEN Trial

Introduction Timely diagnosis of iron deficiency is crucial for managing anemia in patients with non-dialysis-dependent chronic kidney disease (ND-CKD). However, iron status results are not always immediately available. We aimed to examine the performance of mean corpuscular volume (MCV) in diagnosing iron deficiency as a primary objective and of iron status in predicting the onset of iron deficiency as a secondary objective. Methods This retrospective cohort study included adult patients with ND-CKD from the BRIGHTEN (oBservational clinical Research In chronic kidney disease patients with renal anemia: renal proGnosis in patients with Hyporesponsive anemia To Erythropoiesis-stimulating agents, darbepoetiN alfa) trial (enrolled from June 2014 to September 2016) in Japan who were started on darbepoetin-alpha for renal anemia and patients who were not started on iron supplementation during weeks 0-24. Diagnostic performance analysis assessed the MCV at week 24 and changes in MCV from week 12 to 24 for diagnosing iron deficiency (ferritin < 100 ng/mL) at week 24, using receiver operating characteristic curves, area under the curve (AUC), sensitivity, and specificity. For the patients without iron deficiency at week 12, ferritin levels at week 12 were assessed by predictive performance analysis to predict new-onset iron deficiency at week 24. Results A total of 796 participants were included in the diagnostic performance analysis (mean age, 70.0 years; mean estimated glomerular filtration rate, 19.2 mL/min/1.73 m²), and 338 were included in the predictive performance analysis. Diagnostic performance analysis revealed an AUC for MCV of 0.55 (95% confidence interval (CI), 0.51-0.59); for MCV changes, it was 0.52 (95% CI, 0.48-0.57). Prognostic performance analysis revealed that ferritin at week 12 demonstrated an AUC of 0.77 (95% CI, 0.67-0.86), with a sensitivity of 83% and a specificity of 66% at a cutoff of 131.5 ng/mL. Conclusion Neither MCV nor the changes in MCV could reliably diagnose iron deficiency in patients with ND-CKD. Ferritin level < 130 ng/mL could predict new-onset iron deficiency within 12 weeks.

Intravenous iron in chronic kidney disease without anaemia but iron deficiency: A scoping review

Iron deficiency (ID) is a prevalent complication of chronic kidney disease (CKD), often managed reactively when associated with anaemia. This scoping review evaluates the evidence supporting intravenous (IV) iron therapy in non-anaemic individuals with CKD and ID, focusing on safety, efficacy, and emerging therapeutic implications. Current diagnostic markers, including serum ferritin, transferrin saturation, and reticulocyte haemoglobin content, are reviewed alongside their limitations in the context of inflammation and variability. The pathophysiology of ID in CKD is explored, highlighting the roles of hepcidin, hypoxia-inducible factor pathways, and uraemic toxins. Comparative studies reveal that IV iron offers a more rapid correction of iron stores, improved compliance, and fewer gastrointestinal side effects compared to oral iron. Evidence from trials such as "iron and heart" and "iron and muscle" suggests potential benefits of IV iron on functional capacity and fatigue, though findings were statistically non-significant. Insights from heart failure trials support the safety and efficacy of IV iron in improving quality of life and reducing hospitalizations, with newer formulations like ferric derisomaltose demonstrating favourable safety profiles. This review underscores the need for standardized screening protocols for ID in CKD, even in the absence of anaemia, to facilitate earlier intervention. Future research should prioritise robust outcome measures, larger sample sizes, and person-specific treatment strategies to optimise dosing and administration frequency. Tailored approaches to IV iron therapy have the potential to significantly improve functional outcomes, quality of life, and long-term health in people with CKD.

Anemia Management in the Cardiorenal Patient: A Nephrological Perspective

Heart failure (HF) and chronic kidney disease (CKD) frequently coexist, sharing significant overlap in prevalence and pathophysiological mechanisms. This coexistence, termed cardiorenal syndrome (CRS), often leads to anemia, which exacerbates both HF and CKD, thereby increasing morbidity and death. Managing anemia in CRS is complex due to conflicting guidelines and the multifactorial nature of the condition. Anemia in CRS is influenced by factors such as inadequate erythropoietin production, iron deficiency, reduced red blood cell life span, and chronic inflammation, which inhibit iron absorption and mobilization. This interplay of mechanisms worsens anemia, further aggravating HF and CKD. Anemia significantly impacts the prognosis of both HF and CKD, and recent trials have shown that hemoglobin increases, particularly with sodium-glucose cotransporter 2 inhibitors, can improve outcomes in patients with HF and CKD. Iron deficiency is also prevalent in both patients with HF and patients with CKD and is associated with poorer exercise capacity and a higher mortality rate. Guidelines for diagnosing and treating iron deficiency differ between HF and CKD. Furthermore, treatment of anemia in CRS is controversial: While sodium-glucose cotransporter 2 inhibitors and intravenous iron has shown consistent benefits in patients with CRS, normalization of hemoglobin with erythropoiesis-stimulating agents improves symptoms and quality of life but have not consistently demonstrated cardiovascular benefits. There are no definitive guidelines for anemia management in CRS. Treatment should address HF, CKD, and anemia concurrently. A proposed algorithm includes correcting iron deficiency, initiating sodium-glucose cotransporter 2 inhibitors, and considering erythropoiesis-stimulating agents if hemoglobin remains <10 g/dL. Further research is needed to optimize anemia management strategies in patients with CRS.

Ziltivekimab for anemia and atherosclerosis in chronic kidney disease: a new hope?

Anemia of chronic kidney disease is a multifactorial condition secondary to various etiologies, including nutritional deficiencies, chronic inflammation, erythropoietin deficiency or resistance, bone marrow suppression, iron deficiency and adverse drug effects. The major therapeutic intervention for anemia among chronic kidney disease patients is erythropoiesis-stimulating agents. However, a limitation of erythropoiesis-stimulating agents is the risk for thromboembolic events, hypertension, seizures, solid organ malignancies and hyporesponsiveness. A novel interleukin-6 monoclonal antibody, ziltivekimab, has been evaluated for managing anemia in chronic kidney disease patients in pilot clinical trials with promising outcomes, including an improvement in hemoglobin levels and reduction of inflammatory parameters. These trials have shown that ziltivekimab does not increase the risk for cytopenia or infectious complications as has been described for other interleukin-6-targeting monoclonal antibodies, like tocilizumab. Furthermore, potentially beneficial effects on serum lipid profile have been reported, leading to the hypothesis of a favorable impact of the drug on atherosclerotic complications. In addition, ziltivekimab has shown efficacy in improving anemia parameters, including hemoglobin levels and iron studies. Ziltivekimab deserves full scale clinical development, and to this aim, large-scale clinical trials are under way.

Regulation of the blood-brain barrier function by peripheral cues in health and disease

The blood-brain barrier (BBB) is formed by microvascular endothelial cells which are ensembled with pericytes, astrocytes, microglia and neurons in the neurovascular unit (NVU) that is crucial for neuronal function. Given that the NVU and the BBB are highly dynamic and regulated structures, their integrity is continuously challenged by intrinsic and extrinsic factors. Herein, factors from peripheral organs such as gonadal and adrenal hormones may influence vascular function also in CNS endothelial cells in a sex- and age-dependent manner. The communication between the periphery and the CNS likely takes place in specific areas of the brain among which the circumventricular organs have a central position due to their neurosensory or neurosecretory function, owing to physiologically leaky blood vessels. In acute and chronic pathological conditions like liver, kidney, pulmonary disease, toxins and metabolites are generated that reach the brain via the circulation and may directly or indirectly affect BBB functionality via the activation of the immunes system. For example, chronic kidney disease (CKD) currently affects more than 840 million people worldwide and is likely to increase along with western world comorbidities of the cardio-vascular system in continuously ageing societies. Toxins leading to the uremic syndrome, may further lead to neurological complications such as cognitive impairment and uremic encephalopathy. Here we summarize the effects of hormones, toxins and inflammatory reactions on the brain vasculature, highlighting the urgent demand for mechanistically exploring the communication between the periphery and the CNS, focusing on the BBB as a last line of defense for brain protection.

Comparative iron management in hemodialysis and peritoneal dialysis patients: a systematic review

Background

Patients with kidney failure undergoing dialysis often suffer from anemia. Iron deficiency, along with a shortage in erythropoietin, is a common cause. Peritoneal dialysis (PD) patients may have a different iron metabolism compared to hemodialysis (HD) patients. This study aims to compare both dialysis modalities regarding their differences in iron management.

Methods

PubMed (MEDLINE) and Embase were screened for randomized controlled trials and observational studies including both patients on HD or PD with information on iron management. Outcomes for iron management for this systematic review included: prevalence of supplementation, route of administration, dose, frequency and hemoglobin and iron status parameters.

Results

15 eligible studies (930,436 patients), of which 8 cohort and 7 cross-sectional, were analyzed. The prevalence of intravenous (IV) iron supplementation ranged from 11.7% to 84.4% in HD patients, compared to 1.6% to 49.0% in PD patients. Ten studies reported that HD patients only received IV iron, while five studies reported this for PD patients. For oral iron supplementation, three studies involved HD patients, whereas seven studies involved PD patients. The cumulative monthly IV iron dose ranged from 108 to 750 mg in the HD group, compared to 65 to 250 mg in the PD group. Hemoglobin levels ranged from 10.0 to 12.0 g/dL in HD patients, versus 9.6 to 11.9 g/dL in PD patients.

Conclusion

Iron management differs between HD and PD patients, with HD patients receiving higher doses and more frequent IV iron. There was significant heterogeneity in the outcomes between the studies, primarily due to the lack of a uniform global policy on iron management. Despite these differences, hemoglobin levels and iron status parameters were comparable between the two groups. Future research should explore the underlying mechanisms and broader impacts of iron treatment, including patient-reported outcomes, to optimize anemia management and improve quality of life for dialysis patients.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022336970.

Associations of anaemia and iron deficiency with health-related quality of life in patients with chronic kidney disease stage G3b-5 in Japan: sub analysis of the Reach-J CKD cohort study

BACKGROUND

Iron deficiency is a major contributor to anaemia in chronic kidney diseases. The association of anaemia and iron deficiency with health-related quality of life in Japanese patients with non-dialysis chronic kidney disease has not been examined. In this study, we evaluated anaemia and iron deficiency in patients with chronic kidney disease G3b-5 and examined their associations with health-related quality of life.

METHODS

This nationwide cohort study included 2,249 patients with advanced chronic kidney disease receiving nephrologist care from 31 representative facilities throughout Japan; they were randomly selected through stratification by region and facility size and aligned with the Chronic Kidney Disease Outcomes and Practice Patterns Study. Using baseline patient data, we assessed the association of anaemia and iron deficiency with health-related quality of life, employing the 36-item Kidney Disease Quality of Life Questionnaire.

RESULTS

The mean mental and physical component summary scores for all patients were 49 and 47, respectively. Patients with haemoglobin levels < 10 g/dL had worse three kidney disease subscale, mental component summary, physical component summary, and subdomain scores than those with haemoglobin levels > 12 g/dL. Patients with absolute iron deficiency (TSAT < 20% and ferritin < 100 ng/mL) had worse three kidney disease subscale and mental component summary scores than those with functional iron deficiency (TSAT < 20% and ferritin ≥ 100 ng/mL).

CONCLUSIONS

Japanese patients with chronic kidney disease G3b-5 with anaemia or absolute iron deficiency had worse health-related quality of life. Our results provide clinical evidence of renal anaemia in Japan and will be useful for international comparisons.

Study protocol for a consortium linking health medical records, biospecimens, and biosignals in Korean patients with acute kidney injury (LINKA cohort)

Background

Acute kidney injury (AKI) may transition into acute kidney disease (AKD) or chronic kidney disease (CKD), leading to subacute and chronic deterioration, respectively. Despite extensive research on AKI, a significant gap exists in understanding the specific biomarkers and development of individualized treatments prior to progression to AKD and CKD.

Methods

As a consortium linking health medical records, biospecimens, and biosignals, eight Korean tertiary hospitals participated in the establishment of a retrospective and prospective cohort, each comprising approximately 1,500 patients with AKI receiving continuous kidney replacement therapy (CKRT). Other information included AKI-related information, CKRT prescriptions, and patient outcomes. Follow-up timeframes were set at baseline, 1 week, 3 months, and 1 year after the initiation of CKRT. Human biospecimens will be collected from the prospective cohort. An artificial intelligence model was developed using the retrospective cohort to predict the prognosis of AKD and its subsequent sequelae and to formulate patient-individualized treatments, with validation planned in a prospective cohort. Follow-up studies are scheduled to identify biomarkers related to outcomes using biospecimens. Finally, based on the results and literature review, decision-making on the prevention and management of diseases, as well as the development of treatment guidelines, are being planned.

Conclusion

This study will provide scientific evidence on clinical insights and appropriate management targets for AKI and AKD, which will form the basis for relevant treatment guidelines. Additionally, these findings may facilitate a more personalized approach to patient care, enabling clinicians to tailor treatments based on individual biomarker profiles and predictive models.

Safety and Efficacy of Vadadustat Once Daily and Three Times Weekly in Patients With Dialysis-Dependent CKD With Anemia

Key Points

Background

Vadadustat is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor for treating anemia in CKD. This study investigated the safety and efficacy of once-daily and three-times-weekly dosing in patients with dialysis-dependent CKD compared with darbepoetin alfa (DA).

Methods

This phase 3b, randomized (1:1:1; vadadustat once daily [starting dose: 300 or 450 mg], vadadustat three times weekly [starting dose: 600 or 750 mg], DA), open-label, active-controlled, noninferiority trial included conversion (weeks 0–20) and maintenance (weeks 20–52) periods. Primary and secondary efficacy end points were mean change in hemoglobin from baseline during the primary evaluation period (PEP, weeks 20–26) and secondary evaluation period (weeks 46–52). Other end points included proportion of patients requiring erythropoiesis-stimulating agent (ESA) rescue (hemoglobin <9.5 g/dl or with increases in dose ≥50% or ≥100% in the DA group). Safety end points included treatment-emergent adverse events (AEs) and serious AEs.

Results

The least-squares (LS) mean treatment difference between vadadustat once daily and DA from baseline to PEP was −0.27 g/dl (95% confidence interval [CI], −0.55 to 0.01); the lower bound met the noninferiority threshold (−0.75 g/dl). The LS mean treatment difference between vadadustat three times weekly and DA from baseline to PEP was −0.53 g/dl (95% CI, −0.80 to −0.25), which did not meet the lower bound noninferiority threshold. The LS mean change from baseline to the secondary evaluation period between DA and vadadustat once daily was −0.40 (95% CI, −0.79 to −0.02) and for vadadustat three times weekly was −0.42 (95% CI, −0.81 to −0.02). The proportion of patients who received ESA rescue during weeks 2–52 was higher in the DA group than vadadustat groups. Similar treatment-emergent AEs and treatment-emergent serious AEs were observed across groups.

Conclusions

Vadadustat once daily, but not three times weekly, was noninferior to DA in the correction and maintenance of hemoglobin in patients with dialysis-dependent CKD converted from an ESA; safety profiles were similar across groups.

Clinical Trial registry name and registration number:

EudraCT 2019-004851-36/ClinicalTrials.gov identifier: NCT04313153.

Post-transplant renal anemia: a call to action from a national study in routine clinical practice

Background

Post-transplant anemia is a prevalent yet often overlooked condition that poses significant risks. Current guidelines consider the same treatment recommendations and goals for these patients as for chronic kidney disease patients not on dialysis. Previous reports demonstrated a lack of awareness and suboptimal management, indicating a pressing need for improvement. We therefore wanted to update the information on post-transplant anemia. We aimed to describe the present state of anemia management, goals and adherence to guidelines within a representative sample of the kidney transplant (KTx) population.

Methods

We designed a retrospective nationwide multicenter study including outpatients from eight KTx hospitals. Nephrologists gathered data from electronic medical records encompassing demographics, comorbidities, KTx characteristics and immunosuppressive therapy, and information pertaining to anemia management (laboratory values, previously prescribed treatments and subsequent adjustments). The European statement on the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines was the reference for definitions, drug prescriptions and targets. Anemia occurring within the initial 6 months post-transplantation was classified as early onset.

Results

We included 297 patients with post-transplant anemia aged 62.8 years (standard deviation 13.6), 60% of whom were male. They had received a graft from cardiac death or brain death donors (61.6% and 31.1%, respectively) a median of 2.5 years (0.5-8.7) before. Among them 77% (n = 228) were classified as having late post-transplant anemia, characterized by a higher prevalence of microcytic and iron deficiency anemia. A total of 158 patients were on erythropoietic-stimulating agents (ESAs) treatment, yet surprisingly 110 of them lacked iron supplementation. Notably, 44 patients had an indication for iron supplementation and among them, 30 exhibited absolute iron deficiency. Out of the 158 patients receiving ESAs, only 39 surpassed the limit for the ESA resistance index, indicating poor response. This resistance was more frequent among patients with early post-transplant anemia (26.1% vs 9.2%). We have identified iron profile, early post-transplant anemia and estimated glomerular filtration rate as factors associated with the highest risk of resistance.

Conclusion

We found that hemoglobin targets are individualized upwards in post-transplant anemia. In this setting, iron therapy continues to be underutilized, especially intravenous, and iron deficiency and prior events (blood transfusion or hospital admission) explain most of the hyporesponsiveness to ESA. This highlights missed opportunities for precise prescription targeting and adherence to established guidelines, suggesting a need for improved management strategies in post-transplant anemia patients.

Anaemia and quality of life in chronic kidney disease: a consensus document from the European Anaemia of CKD Alliance

Anaemia is common in chronic kidney disease (CKD) and has a significant impact on quality of life (QoL), work productivity and outcomes. Current management includes oral or intravenous iron and erythropoiesis-stimulating agents (ESAs), to which hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) have been recently added, increasing the available therapeutic options. In randomised controlled trials, only intravenous iron improved cardiovascular outcome, while some ESAs were associated with increased adverse cardiovascular events. Despite therapeutic advances, several challenges and unmet needs remain in the current management of anaemia of CKD. In particular, clinical practice does not include an assessment of QoL, which prompted a group of European nephrologists and representatives of patient advocacy groups to revisit the current approach. In this consensus document, the authors propose a move towards a more holistic, personalised and long-term approach, based on existing evidence. The focus of treatment should be on improving QoL without increasing the risk of adverse cardiovascular events, and tailoring management strategies to the needs of the individual. In addition, the authors discuss the suitability of a currently available anaemia of CKD-specific health-related QoL measure for inclusion in the routine clinical management of anaemia of CKD. The authors also outline the logistics and challenges of incorporating such a measure into electronic health records and how it may be used to improve QoL for people with anaemia of CKD.

Quantification of the Plasma Concentration of Vadadustat by High-Performance Liquid Chromatography with Ultraviolet Detection and Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry

BACKGROUND

An inexpensive, simple, and accurate plasma concentration measurement system is needed to actively conduct pharmacokinetic and pharmacodynamic analyses of vadadustat, hypoxia-inducible factor-prolyl hydroxylase inhibitor, in clinical settings. In this study, the authors aimed to develop a method for measuring vadadustat in human plasma that could be applied for therapeutic drug monitoring using high-performance liquid chromatography with ultraviolet detection (HPLC-UV) in a clinical setting.

METHODS

Plasma samples (100 μL) were pretreated with acetonitrile using butyl paraoxybenzoate as an internal standard. Chromatographic separation was performed on a SunShell PFP C18 column (2.6 μm, 4.6 mm × 150 mm). The mobile phase consisted of (A) 20 mM of phosphate buffer (pH 2.4) and (B) acetonitrile (60:40, v/v), delivered isocratically at a flow rate of 1 mL/min. The analytes were detected by UV absorbance at a wavelength of 220 nm, and the column temperature was 40°C. To evaluate the applicability of HPLC-UV in a clinical setting, blood samples were collected at 19 time points from 7 patients who had been taking vadadustat.

RESULTS

The calibration curve was linear over the concentration range of 0.2-150 mcg/mL (R2 > 0.99). Intra-assay and interassay accuracy, precision, and stability met the Food and Drug Administration recommendations. The vadadustat plasma concentrations of patients analyzed using the current HPLC-UV method were almost equal to those measured using ultra-performance liquid chromatography-tandem mass spectrometry (mean difference: 0.13 mcg/mL). Large variability in the dose-adjusted plasma concentrations of vadadustat at 12 hours after administration was observed between patients (coefficient of variation = 57.6%).

CONCLUSIONS

This HPLC-UV method is a simple, accurate quantification method for evaluating plasma concentrations in patients taking vadadustat in a clinical setting.

Mendelian Randomization Analysis of Systemic Iron Status and Risk of Different Types of Kidney Disease

With rapid increases in incidence, diverse subtypes, and complicated etiologies, kidney disease remains a global public health problem. Iron, as an essential trace element, has pleiotropic effects on renal function and the progression of kidney diseases. A two-sample Mendelian randomization (MR) analysis was implemented to determine the potential causal effects between systemic iron status on different kidney diseases. Systemic iron status was represented by four iron-related biomarkers: serum iron, ferritin, transferrin saturation (TfSat), and total iron binding capacity (TIBC). For systemic iron status, 163,511, 246,139, 131,471, and 135,430 individuals were included in the genome-wide association study (GWAS) of serum iron, ferritin, TfSat, and TIBC, respectively. For kidney diseases, 653,143 individuals (15,658 cases and 637,485 controls), 657,076 individuals (8160 cases and 648,916 controls), and 659,320 individuals (10,404 cases and 648,916 controls) were included for immunoglobulin A nephropathy (IgAN), acute kidney disease (AKD), and chronic kidney disease (CKD), respectively. Our MR results showed that increased serum iron [odds ratio (OR): 1.10; 95% confidence interval (95% CI): 1.04, 1.16; p < 0.0042], ferritin (OR: 1.30; 95% CI: 1.14, 1.48; p < 0.0042), and TfSat (OR: 1.07; 95% CI: 1.04, 1.11; p < 0.0042)] and decreased TIBC (OR: 0.92; 95% CI: 0.88, 0.97; p < 0.0042) were associated with elevated IgAN risk. However, no significant associations were found between systemic iron status and AKD or CKD. In our MR study, the genetic evidence supports elevated systemic iron status as a causal effect on IgAN, which suggests a potential protective effect of iron chelation on IgAN patients.

Can we effectively manage chronic kidney disease with a precision-based pharmacotherapy plan? Where are we?

INTRODUCTION

In recent years, thanks to significant advances in basic science and biotechnologies, nephrology has witnessed a deeper understanding of the mechanisms leading to various conditions associated with or causing kidney disease, opening new perspectives for developing specific treatments. These new possibilities have brought increased challenges to physicians, who face with a new complexity in disease characterization and selection the right treatment for individual patients.

AREAS COVERED

We chose four therapeutic situations: anaemia in chronic kidney disease (CKD), heart failure in CKD, IgA nephropathy (IgAN) and membranous nephropathy (MN). The literature search was made through PubMed.

EXPERT OPINION

Anaemia management remains challenging in CKD; a personalized therapeutic approach is often needed. Identifying patients who could benefit from a specific therapy is also an important goal for patients with CKD and heart failure with reduced ejection fraction. Several new treatments are under clinical development for IgAN; interestingly, they target specifically the pathogenetic mechanisms of the disease. The understanding of MN pathogenesis as an autoimmune disease and the discovery of several autoantibodies allows a better characterization of patients. High-sensible techniques for lymphocyte counting open the possibility of more personalized use of anti CD20 therapies.

Critical re-evaluation of the identification of iron deficiency states and effective iron repletion strategies in patients with chronic heart failure

According to current guidelines, iron deficiency is defined by a serum ferritin level <100 ng/ml or a transferrin saturation (TSAT) <20% if the serum ferritin level is 100-299 μg/L. These criteria were developed to encourage the use of intravenous iron as an adjunct to erythropoiesis-stimulating agents in the treatment of renal anaemia. However, in patients with heart failure, these criteria are not supported by any pathophysiological or clinical evidence that they identify an absolute or functional iron deficiency state. A low baseline TSAT-but not serum ferritin level-appears to be a reliable indicator of the effect of intravenous iron to reduce major heart failure events. In randomized controlled trials, intravenous iron decreased the risk of cardiovascular death or total heart failure hospitalization in patients with a TSAT <20% (risk ratio 0.67 [0.49-0.92]) but not in patients with a TSAT ≥20% (risk ratio 0.99 [0.74-1.30]), with the magnitude of the risk reduction being proportional to the severity of hypoferraemia. Patients who were enrolled in clinical trials solely because they had a serum ferritin level <100 μg/L showed no significant benefit on heart failure outcomes, and it is noteworthy that serum ferritin levels of 20-300 μg/L lie entirely within the range of normal values for healthy adults. Current guidelines reflect the eligibility criteria of clinical trials, which inadvertently adopted unvalidated criteria to define iron deficiency. Reliance on these guidelines would lead to the treatment of many patients who are not iron deficient (serum ferritin level <100 μg/L but normal TSAT) and ignores the possibility of iron deficiency in patients with a low TSAT but with serum ferritin level of >300 μg/L. Importantly, analyses of benefit based on trial eligibility-driven guidelines substantially underestimate the magnitude of heart-failure-event risk reduction with intravenous iron in patients who are truly iron deficient. Based on all available data, we recommend a new mechanism-based and trial-tested approach that reflects the totality of evidence more faithfully than the historical process adopted by clinical investigators and by the guidelines. Until additional evidence is forthcoming, an iron deficiency state in patients with heart failure should be defined by a TSAT <20% (as long as the serum ferritin level is <400 μg/L), and furthermore, the use of a serum ferritin level <100 μg/L alone as a diagnostic criterion should be discarded.

Anemia of Chronic Kidney Disease-A Narrative Review of Its Pathophysiology, Diagnosis, and Management

Anemia is one of the most common chronic kidney disease (CKD) complications. It negatively affects patients' quality of life and clinical outcomes. The pathophysiology of anemia in CKD involves the interplay of various factors such as erythropoietin (EPO) deficiency, iron dysregulation, chronic inflammation, bone marrow dysfunction, and nutritional deficiencies. Despite recent advances in understanding this condition, anemia still remains a serious clinical challenge in population of patients with CKD. Several guidelines have been published with the aim to systematize the diagnostic approach and treatment of anemia; however, due to emerging data, many recommendations vary between publications. Recent studies indicate a potential of novel biomarkers to evaluate anemia and related conditions such as iron deficiency, which is often present in CKD patients. Our article aims to summarize the pathophysiology of anemia in CKD, as well as the diagnosis and management of this condition, including novel therapeutic approaches such as hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHI). Understanding these complex subjects is crucial for a targeted approach to diagnose and treat patients with anemia in CKD effectively.

Iron Deficiency in Newly Referred Patients With Chronic Renal Failure

Addressing iron deficiency is the key to managing anemia in patients with chronic kidney disease (CKD). Erythropoiesis-stimulating agents (ESAs) and hypoxia-inducible factor prolyl-hydroxylase inhibitors (HIF-PHIs) are being prescribed to an increasing number of patients with CKD by primary physicians following the emergence of newer agents for the management of renal anemia. Among the 361 (average age: 76.8±12.1 years; 54.0% males) patients with stages 4 and 5 CKD newly referred to the nephrology department of our hospital between 2018 and 2023 who had evaluable transferrin saturation (TSAT) and ferritin levels, 169 patients (47%) had iron deficiency (ferritin <100 ng/mL or ferritin 100-300 ng/mL with TSAT <20%). The estimated glomerular filtration rate (eGFR), hemoglobin level, TSAT, and median ferritin level were 17.0±7.0 mL/min/1.73 m², 10.8±2.1 g/dL, 27.5±13.1%, and 130 ng/mL, respectively. ESAs, HIF-PHIs, and iron supplements were prescribed to 35 (9.7%), 17 (4.7%), and 35 (9.4%) patients, respectively. No significant differences were observed between the iron indices of the ESA group; however, the serum ferritin levels in the HIF-PHIs group were significantly lower than in those in the no-medication group (P=0.02). Multivariable logistic regression analysis revealed that age, female sex, eGFR, medications for renal anemia, and a history of ischemic heart disease were associated with iron deficiency (P<0.05). Although patients with renal failure tend to exhibit anemia, attention should be paid to iron deficiency anemia in addition to renal anemia, especially in patients with renal failure and a history of ischemic heart disease.

A novel scenario in the therapeutic management of anemia of chronic kidney disease: placement and use of roxadustat

Anemia is a frequent and early chronic kidney disease (CKD) complication. Its management is currently based on oral or intravenous iron supplements, erythropoiesis-stimulating agents, and red blood cell transfusions, when the benefits of transfusion outweigh the risks. Anemia in CKD patients is underdiagnosed and undertreated. Current standard of care is associated with challenges and therefore new treatment approaches have been sought. Hypoxia-inducible factor-prolyl-hydroxylase enzyme inhibitors are a new class of orally administered drugs used to treat anemia associated with CKD. Small-molecule hypoxia-inducible factor-prolyl-hydroxylase inhibitors have a novel mechanism of action that activates the hypoxia-inducible factor (oxygen-sensing) pathway resulting in a coordinated erythropoietic response, leading to increased endogenous erythropoietin production, improved iron absorption and transport, and reduced hepcidin. Roxadustat is the first hypoxia-inducible factor-prolyl-hydroxylase inhibitor approved by the European Medicines Agency (EMA) and reimbursed in Italy by the Italian Medicines Agency (AIFA) for the treatment of adult patients with symptomatic CKD-related anemia. This authorization was based on the outcome of a globally-conducted phase 3 clinical trial program comprising eight pivotal multicenter randomized studies. In the absence of up-to-date guidelines, we performed a critical appraisal of the placement and use of roxadustat in this therapeutic context.

Immune Response after Anti-SARS-CoV-2 mRNA Vaccination in Relation to Cellular Immunity, Vitamin D and Comorbidities in Hemodialysis Patients

In the global threat of SARS-CoV-2, individuals undergoing maintenance dialysis represent a vulnerable population with an increased risk of severe COVID-19 outcomes. Therefore, immunization against SARS-CoV-2 is an essential component of healthcare strategy for these patients. Existing data indicate that they tend to exhibit a reduced immune response to vaccines compared to the general population. Our study aimed to assess both humoral and cellular immune responses following two doses of an anti-SARS-CoV-2 mRNA vaccine, an ability to maintain adequate antibody titers over time, and potential relations with vitamin D, comorbidities and other factors in hemodialysis patients based on a single center experience. A total of 41/45 patients (91.1%) responded to the second dose of the anti-SARS-CoV-2 mRNA vaccine. The titer of anti-SARS-CoV-2 IgG class antibodies and levels of T cells three to four weeks after vaccination were lower in dialysis patients than in healthy controls. Antibodies titer in dialysis patients had a positive correlation with B lymphocytes and was related to cardiovascular diseases. The level of CD4+ cells had a negative correlation with hemodialysis vintage, as did the vitamin D level with post-vaccination seroconversion and decline in anti-SARS-CoV-2 antibodies titer during six months after vaccination. Hemodialysis patients had decreased amounts of CD4+ and CD8+ cells and lower levels of anti-SARS-CoV-2 antibodies than healthy controls. Therefore, chronic hemodialysis could lead to diminished cellular immunity and humoral immune response to the anti-SARS-CoV-2 mRNA vaccination and reduced protection from COVID-19. Comorbidity in cardiovascular diseases was associated with a lower level of specific anti-SARS-CoV-2 antibody titer. Vitamin D may be important in maintaining stable levels of anti-SARS-CoV-2 antibodies, while the duration of dialysis treatment could be one of the factors decreasing anti-SARS-CoV-2 antibody titer and determining lower CD4+ cell counts.

Efficacy and Safety of Oral Supplementation with Liposomal Iron in Non-Dialysis Chronic Kidney Disease Patients with Iron Deficiency

INTRODUCTION

Iron deficiency is common in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD). Oral iron supplementation is recommended in these patients, but it is associated with a higher incidence of gastrointestinal adverse reactions. Liposomal iron therapy has been proposed as a new iron formulation, improving iron bioavailability with less side effects; however, few data are available in patients with NDD-CKD.

METHODS

We designed a single-arm pilot study to evaluate the efficacy of liposomal iron administered for six months in correcting iron deficiency (defined as serum ferritin < 100 ng/mL and/or transferrin saturation < 20%) in patients with NDD-CKD stages 1-5. The primary endpoints were the achievement of serum ferritin ≥ 100 ng/mL and transferrin saturation ≥ 20%. Secondary outcomes were hemoglobin (Hb) changes and the safety of liposomal iron.

RESULTS

The efficacy population included 34/38 patients, who completed at least one visit after baseline. Liposomal iron increased the achievement of transferrin saturation targets from 11.8% at baseline to 50.0% at month 6 (p = 0.002), while no significant correction of serum ferritin (p = 0.214) and Hb was found (p = 0.465). When patients were stratified by anemia (Hb < 12 g/dL in women and Hb < 13 g/dL in men), a significant improvement of transferrin saturation was observed only in anemic patients (from 13.3 ± 5.8% to 20.2 ± 8.1%, p = 0.012). Hb values slightly increased at month 6 only in anemic patients (+0.60 g/dL, 95%CI -0.27 to +1.48), but not in those without anemia (+0.08 g/dL, 95%CI -0.73 to +0.88). In patients taking at least one dose of liposomal iron (safety population, n = 38), the study drug was discontinued in eight patients due to death (n = 2), a switch to intravenous iron (n = 2), and the occurrence of side effects (n = 4).

CONCLUSIONS

The use of liposomal iron in patients with NDD-CKD is associated with a partial correction of transferrin saturation, with no significant effect on iron storage and Hb levels.

Consensus commentary and position of the Italian Society of Nephrology on KDIGO controversies conference on novel anemia therapies in chronic kidney disease

Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) are new drugs developed for the treatment of anemia associated with chronic kidney disease (CKD). This class of drugs stimulates endogenous erythropoietin production and, at the same time, improves iron absorption and mobilization of iron stores (less evident with daprodustat, vadadustat and enarodustat). Several studies have been published in the last few years showing that these agents are not inferior to standard therapy in correcting anemia associated with CKD. The efficacy of HIF-PHIs is coupled with a safety profile comparable to that of standard erythropoiesis stimulating agent (ESA) treatment. However, studies with HIF-PHIs were not long enough to definitively exclude the impact of new drugs on adverse events, such as cancer, death and possibly cardiovascular events, that usually occur after a long follow-up period. Kidney Disease: Improving Global Outcomes (KDIGO) recently reported the conclusions of the Controversies Conference on HIF-PHIs held in 2021. The goal of the present position paper endorsed by the Italian Society of Nephrology is to better adapt the conclusions of the latest KDIGO Conference on HIF-PHIs to the Italian context by reviewing the efficacy and safety of HIF-PHIs as well as their use in subpopulations of interest as emerged from more recent publications not discussed during the KDIGO Conference.

Risk Factors for Thromboembolic Events in Patients With Dialysis-Dependent CKD: Pooled Analysis of Four Global Roxadustat Phase 3 Trials

INTRODUCTION

Risk factors for thromboembolic events in patients with dialysis-dependent chronic kidney disease (CKD) receiving roxadustat are unknown. Iron deficiency has been reported as a risk factor for thrombosis in the general population.

METHODS

Thromboembolic events with onset before and after week 12 in patients receiving roxadustat were evaluated in this pooled analysis of four global phase 3 trials, PYRENEES, SIERRAS, HIMALAYAS, and ROCKIES. Baseline risk factors for thromboembolic events were investigated by Cox regression analyses. Nested case-control analyses with matched pairs of case-control data explored the relationship between thromboembolic events and last known laboratory parameters before event onset.

RESULTS

Of 2354 patients, 1026 thromboembolic events were observed in 568 patients. Baseline risk factors found included hemodialysis (vs peritoneal dialysis), advanced age (≥ 65 years), Black race, high high-sensitivity C-reactive protein, and history of thromboembolism, cardiovascular disease, or diabetes. Univariate case-control analyses revealed that high hemoglobin rate of rise (≥ 0.5 g/dL/week; odds ratio [OR] 2.09; 95% confidence interval [CI] 0.98-4.46) showed a trend towards increased risk of thromboembolic events before week 12, and high rate of hemoglobin decline was associated with events after week 12 (< - 0.5 g/dL/week; OR 3.73; 95% CI 1.68-8.27) as compared to stable hemoglobin levels (≥ - 0.1 to < 0.1 g/dL/week). Multivariate case-control analyses showed that low last known hemoglobin level (< 10 g/dL: adjusted OR 1.91; 95% CI 1.04-3.50; vs ≥ 12 g/dL) and low last known transferrin saturation (TSAT < 10%: adjusted OR 3.78; 95% CI 1.71-8.39; vs ≥ 30%) before event onset were associated with events after week 12. In patients with last known TSAT < 30%, higher roxadustat dose was associated with thromboembolic events; however, no association was observed in those with TSAT ≥ 30%.

CONCLUSIONS

Among various risk factors for thromboembolic events, it is reasonable to avoid a rapid increase and decline in hemoglobin levels as well as ensure TSAT ≥ 30%, rather than increasing the roxadustat dose. Graphical Abstract available for this article.

TRIAL REGISTRATION

NCT02278341, NCT02273726, NCT02052310, NCT02174731.

Haemoglobin trajectories in chronic kidney disease and risk of major adverse cardiovascular events

BACKGROUND

The trajectories of haemoglobin in patients with chronic kidney disease (CKD) have been poorly described. In such patients, we aimed to identify typical haemoglobin trajectory profiles and estimate their risks of major adverse cardiovascular events (MACE).

METHODS

We used 5-year longitudinal data from the CKD-REIN cohort patients with moderate to severe CKD enrolled from 40 nationally representative nephrology clinics in France. A joint latent class model was used to estimate, in different classes of haemoglobin trajectory, the competing risks of (i) MACE + defined as the first event among cardiovascular death, non-fatal myocardial infarction, stroke or hospitalization for acute heart failure, (ii) initiation of kidney replacement therapy (KRT) and (iii) non-cardiovascular death.

RESULTS

During the follow-up, we gathered 33 874 haemoglobin measurements from 3011 subjects (median, 10 per patient). We identified five distinct haemoglobin trajectory profiles. The predominant profile (n = 1885, 62.6%) showed an overall stable trajectory and low risks of events. The four other profiles had nonlinear declining trajectories: early strong decline (n = 257, 8.5%), late strong decline (n = 75, 2.5%), early moderate decline (n = 356, 11.8%) and late moderate decline (n = 438, 14.6%). The four profiles had different risks of MACE, while the risks of KRT and non-cardiovascular death consistently increased from the haemoglobin decline.

CONCLUSION

In this study, we observed that two-thirds of patients had a stable haemoglobin trajectory and low risks of adverse events. The other third had a nonlinear trajectory declining at different rates, with increased risks of events. Better attention should be paid to dynamic changes of haemoglobin in CKD.

The estimated mediating roles of anemia-related variables in the association between kidney function and mortality: a National Health and Nutrition Examination Survey (NHANES) study

Anemia is a common complication of chronic kidney disease (CKD), impacting long-term outcomes such as mortality and morbidity. Analyzing NHANES data from 1999 through 2016 for adults aged ≥ 20 years, we assessed the mediating effects of anemia biomarkers (hemoglobin, hematocrit, red cell distribution width [RDW], and mean corpuscular hemoglobin concentration [MCHC]) on CKD-related outcomes by using hazard ratios from a biomarker-adjusted model. Of 44,099 participants, 7463 experienced all-cause death. Cox proportional hazard models revealed a higher all-cause mortality risk in the > 45 years and CKD groups than in the early CKD group. Hemoglobin, hematocrit and MCHC were inversely related to all-cause mortality; RDW was related to mortality. Single mediation analysis showed greater mediating effects of anemia indicators on CKD and mortality in the elderly (> 65 years) population than those in the general population. In the multimediation analysis, the combined mediating effect of anemia was higher in the CKD population than in the general population. This study showed a proportional increase in the mediating effect of anemia with CKD stage, suggesting potential therapeutic avenues. However, further exploration of other mediating factors on kidney outcomes is necessary.

Serum ferritin/C-reactive protein ratio is a simple and effective biomarker for diagnosing iron deficiency in the context of systemic inflammation

BACKGROUND

Diagnosing iron deficiency is challenging in the presence of systemic inflammation.

AIM

To investigate the relationship between plasma C-reactive protein (CRP), serum ferritin (SF) and transferrin saturation (TS), with the objective of establishing a straightforward ratio applicable in the presence of inflammatory syndrome.

DESIGN

Test prospective cohort and validation retrospective cohort.

METHODS

A prospective cohort of inpatients (n = 140) assessed the correlation between CRP and SF/TS levels. The diagnostic performance of a determined ratio was evaluated for identifying iron deficiency (ID) using different definitions and in the presence of inflammation and/or chronic heart and/or kidney failure. A large validation cohort (n = 795) further assessed the predictive power of this ratio.

RESULTS

In a training cohort (median age 76 years [57-84]), a linear relation was observed between SF (µg/l) and CRP (mg/l), unlike with TS. The SF/CRP ratio accurately predicted ID, with receiver operating characteristic-area under the curve (ROC-AUC) values ranging from 0.85 to 0.92 for different ID definitions. A threshold of ≤6 demonstrated the highest Youden index (0.61). In the validation cohort (age 72 years [57-84]), the SF/CRP ratio exhibited an ROC-AUC of 0.88 [95% CI: 0.85-0.90], with an odds ratio of 37.9 [95% CI: 20.3-68.9] for the threshold of ≤6.

CONCLUSION

In this study, we demonstrated that the SF/CRP ratio, with a threshold of ≤6, is a simple and effective biomarker for ID, even in the presence of systemic inflammation or comorbidities. This ratio could potentially replace the complex set of criteria currently recommended by learned societies.

Cut-off values of haemoglobin and clinical outcomes in incident peritoneal dialysis: the PDTAP study

BACKGROUND

To explore the cut-off values of haemoglobin (Hb) on adverse clinical outcomes in incident peritoneal dialysis (PD) patients based on a national-level database.

METHODS

The observational cohort study was from the Peritoneal Dialysis Telemedicine-assisted Platform (PDTAP) dataset. The primary outcomes were all-cause mortality, major adverse cardiovascular events (MACE) and modified MACE (MACE+). The secondary outcomes were the occurrences of hospitalization, first-episode peritonitis and permanent transfer to haemodialysis (HD).

RESULTS

A total of 2591 PD patients were enrolled between June 2016 and April 2019 and followed up until December 2020. Baseline and time-averaged Hb <100 g/l were associated with all-cause mortality, MACE, MACE+ and hospitalizations. After multivariable adjustments, only time-averaged Hb <100 g/l significantly predicted a higher risk for all-cause mortality {hazard ratio [HR] 1.83 [95% confidence interval (CI) 1.19-281], P = .006}, MACE [HR 1.99 (95% CI 1.16-3.40), P = .012] and MACE+ [HR 1.77 (95% CI 1.15-2.73), P = .010] in the total cohort. No associations between Hb and hospitalizations, transfer to HD and first-episode peritonitis were observed. Among patients with Hb ≥100 g/l at baseline, younger age, female, use of iron supplementation, lower values of serum albumin and renal Kt/V independently predicted the incidence of Hb <100 g/l during the follow-up.

CONCLUSION

This study provided real-world evidence on the cut-off value of Hb for predicting poorer outcomes through a nation-level prospective PD cohort.

High Ferritin Is Not Needed in Hemodialysis Patients: A Retrospective Study of Total Body Iron and Oral Iron Replacement Therapy

In vivo iron levels can be adjusted through intestinal iron absorption to be maintained at a suitable level; however, optimal iron levels in hemodialysis (HD) patients are unclear. In this study, we investigated total body iron (TBI), calculated as the sum of red blood cell (RBC) iron and iron stores, during courses of low-dose oral iron replacement therapy, and evaluated in vivo iron sufficiency and its indicators in HD patients. We analyzed data on 105 courses of low-dose iron replacement therapy administered to 83 patients on maintenance HD over 7 months. We evaluated changes in TBI, RBC iron, and iron stores from the initiation of treatment to month 7 in two groups of patients, namely, iron-therapy responders and non-responders. TBI showed significant increases until month 4 and plateaued thereafter in iron-therapy responders, and tended to increase and then reached a similar plateau in non-responders (month 7: 1900 ± 447 vs. 1900 ± 408 mg). Steady-state TBI was strongly correlated with body surface area (y = 1628.6x - 791.91, R2 = 0.88, p < 0.001). We observed constant TBI during oral iron replacement therapy suggesting the activation of a "mucosal block". The results suggest that body surface area has utility for estimating the required TBI with regression equations.

How I treat anemia in older adults

ABSTRACT

With the global growing older adult population, clinicians face the common, yet complex challenge of how to evaluate and manage anemia in this population. Older age predisposes to common causes of anemia such as nutritional deficiencies, inflammatory disorders, chronic kidney disease, and hematologic malignancies. Failure to diagnose and appropriately manage anemia may result in decreased quality of life, impaired cognition, impaired mobility, and increased mortality. Anemia diagnosis in older adults presents a diagnostic conundrum because anemia may have a single cause, may be multifactorial, or may have no apparent cause even after an extensive evaluation. We believe a systematic approach to diagnosis ensures appropriate testing and avoids the pitfall of undertreatment and overtreatment. In this article we present our recommended approach through common scenarios for the management of anemia in the older adult.

Risk factors and current state of therapy for anemia after kidney transplantation

Post-transplant anemia is one of the most common complications in kidney transplant recipients, severely affecting patient prognosis and quality of life, and is an independent predictor of graft kidney loss and patient mortality. However, our clinical understanding and the attention given to post-transplant anemia are currently insufficient. This paper reviews the current status, risk factors, and therapeutic progress in anemia after transplantation in kidney transplant recipients. We recommend that clinical staff pay attention to anemia and its complications in kidney transplant recipients and intervene early for anemia.

Relationship between bone marrow iron load and liver iron concentration in dialysis-associated haemosiderosis

BACKGROUND

Iron overload due to the excessive use of parenteral iron in haemodialysis is now an increasingly recognised clinical issue. Before erythropoiesis-stimulating agents (ESA) were introduced, a specific feature of patients treated by dialysis and having iron overload was that iron levels in the bone marrow were paradoxically low in most of them, despite severe hepatosplenic siderosis. Whether or not this paradox persists in the actual ESA era was unknown until recently, when an autopsy study in 21 patients treated by haemodialysis revealed similarities between liver and bone marrow iron content. The aim of this study was to further explore these recent findings in a cohort of alive patients on dialysis and to analyse the determinants of iron bone marrow.

METHODS

Liver iron concentration (LIC) and vertebral T2∗ (a surrogate marker of bone marrow iron) were analysed retrospectively in 152 alive patients on dialysis (38.8% female) of whom 47.4% had iron overload by quantitative magnetic resonance imaging (MRI).

FINDINGS

Vertebral T2∗ differed significantly between patients classified according to liver iron content at MRI: those with mild or moderate and severe liver iron overload had increased vertebral iron content at R2∗ relaxometry MRI (mild: vertebral T2∗ = 9.9 ms (4-24.8); moderate and severe: vertebral T2∗ = 8.5 ms (4.9-22.8)) when compared to patients with normal LIC (vertebral T2∗ = 13.2 ms (6.6-30.5) (p < 0.0001 Kruskal-Wallis test)).

INTERPRETATION

The paradoxical discrepancy between bone marrow and liver iron-storage compartments observed in the pre-ESA era has disappeared today, as shown by a recent autopsy study and the present study in a cohort of alive patients treated by dialysis.

FUNDING

None.

Opportunities to improve the management of anemia in peritoneal dialysis patients: lessons from a national study in routine clinical practice

Background

Current guidelines establish the same hemoglobin (Hb) and iron biomarkers targets for hemodialysis (HD) and peritoneal dialysis (PD) in patients receiving erythropoiesis-stimulating agents (ESAs) even though patients having PD are usually younger, more active and less comorbid. Unfortunately, specific renal anemia [anemia in chronic kidney disease (aCKD)] trials or observational studies on PD are scanty. The aims of this study were to describe current aCKD management, goals and adherence to clinical guidelines, identifying opportunities for healthcare improvement in PD patients.

Methods

This was a retrospective, nationwide, multicentre study including patients from 19 PD units. The nephrologists collected baseline data, demographics, comorbidities and data related to anemia management (laboratory values, previously prescribed treatments and subsequent adjustments) from electronic medical records. The European adaptation of KDIGO guidelines was the reference for definitions, drug prescriptions and targets.

Results

A total of 343 patients (mean age 62.9 years, 61.2% male) were included; 72.9% were receiving ESAs and 33.2% iron therapy [20.7% intravenously (IV)]. Eighty-two patients were receiving ESA without iron therapy, despite 53 of them having an indication according to the European Renal Best Practice guidelines. After laboratory results, iron therapy was only started in 15% of patients. Among ESA-treated patients, 51.9% had an optimal control [hemoglobin (Hb) 10-12 g/dL] and 28.3% between 12-12.9 g/dL. Seventeen patients achieved Hb >13 g/dL, and 12 of them remained on ESA after overshooting. Only three patients had Hb <10 g/dL without ESAs. Seven patients (2%) met criteria for ESA resistance (epoetin dose >300 IU/kg/week). The highest tertile of erythropoietin resistance index (>6.3 UI/kg/week/g/dL) was associated with iron deficiency and low albumin corrected by renal replacement therapy vintage and hospital admissions in the previous 3 months.

Conclusion

Iron therapy continues to be underused (especially IV). Low albumin, iron deficiency and prior events explain most of the ESA hyporesponsiveness. Hb targets are titrated to/above the upper limits. Thus, several missed opportunities for adequate prescriptions and adherence to guidelines were identified.

The anaemia treatment journey of CKD patients: from epoetins to hypoxia-inducible factor-prolyl hydroxylase inhibitors

The discovery and development of erythropoiesis-stimulating agents was a journey lasting more than a century, leading to the cloning and approval of recombinant human erythropoietin (rHuEpo). This was an impressive clinical advance, providing the possibility of correcting the symptoms associated with anaemia in chronic kidney disease. Associated iron use was needed to produce new haemoglobin-containing blood red cells. Partial anaemia correction became the standard of care since trials aiming for near-normal haemoglobin levels showed a higher risk of adverse cardiovascular events. Hoping to reduce the cardiovascular risks, a new category of drugs was developed and tested. Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) are small molecules than can be formulated into orally active pills. They simulate reduced tissue oxygen pressure, thus stimulating the production of endogenous erythropoietin (Epo) by the kidneys and liver. Clinical trials with these compounds demonstrated that HIF-PHIs are at least as effective as rHuEpo in treating or correcting anaemia in non-dialysis and dialysis patients. Trials with HIF-PHIs did not demonstrate superiority in safety outcomes and in some trials, outcomes were worse. There was also a focus on oral delivery, a possible beneficial iron-sparing effect and the ability to overcome Epo resistance in inflamed patients. A negative effect is possible iron depletion, which may explain adverse outcomes.

Continuous Erythropoietin Receptor Activator for the Treatment of Chronic Dialysis Patients with Renal Anemia in Daily Clinical Practice in Poland: A Non-Interventional, Multi-Center, Pragmatic NAVIGO Trial

BACKGROUND

Renal anemia is one of the most common complications of chronic kidney disease (CKD). This real-life study assessed the effectiveness of methoxy polyethylene glycol-epoetin beta, a continuous erythropoietin receptor activator (C.E.R.A.), for the treatment of CKD-associated anemia in patients receiving dialysis in daily clinical practice.

METHODS

247 patients receiving chronic intermitted dialysis in 26 centers in Poland with CKD-associated symptomatic anemia, ESA-naïve, and with balanced iron stores in the investigators' opinion were enrolled this real-life study. Over 12 months, the following data were collected: hemoglobin (Hb) concentration and dosage, route of administration and dosing scheme of C.E.R.A., dialysis adequacy, adverse events, iron therapy, and blood transfusions.

RESULTS

During the treatment, a Hb concentration of ≥10 g/dL was noted in 90.9% of hemodialysis patients (n = 224) and 96.0% of peritoneal dialysis patients (n = 23). At baseline, 7.8% of patients had a Hb concentration of 10-12 g/dL, which increased to 63.3% after 12 months. The median time when Hb concentration was maintained within 10-12 g/dL was 115.2 (interquartile range 49.1-188.7) days. A Hb concentration ≥12 g/dL was observed after 7 months of treatment in a maximum of 24.1% of hemodialysis patients, and 31.8% of peritoneal dialysis patients. The median time elapsed between the start of treatment and the first Hb concentration >10 g/dL was 42.0 (21.0-78.2) days. C.E.R.A. was well tolerated.

CONCLUSIONS

C.E.R.A. corrects CKD-associated anemia in dialysis patients, and maintains Hb levels within the recommended target range. The study also confirmed the acceptable safety profile of the drug.

Infectious Risk and Variability of Hemoglobin Level in Patients Undergoing Hemodialysis

Introduction

In the management of anemia in chronic kidney disease, hemoglobin levels often fall below or exceed target ranges. Past retrospective cohort studies of patients undergoing hemodialysis with conventional erythropoiesis stimulating agents (ESAs) found that hemoglobin level fluctuations predicted mortality and cardiovascular adverse events; long-acting agents were thereafter widely available. An updated validation by a prospective cohort study was needed.

Methods

Using Cox regression models, we evaluated associations between hemoglobin variability and all-cause death, hospitalization, and cardiovascular, thrombotic, or infectious adverse event outcomes in 3063 hemodialysis patients' data from the Japanese Dialysis Outcomes and Practice Patterns Study (J-DOPPS) from 2012 to 2018.

Results

During a median follow-up time of 2.5 years, all-cause mortality was lowest in the first quartile and tended to be higher in groups with greater hemoglobin variability (hazard ratio [HR]: 95% confidence interval for the fourth quartile of an absolute value of hemoglobin variability: 1.44 [0.99-2.08], P for trend = 0.056). Infectious event incidence in these patients was also lower in the first quartile than for the other quartiles (P for trend < 0.01). The association was more pronounced in patients with lower serum ferritin levels or iron supplementation. Cardiovascular and thrombotic event incidence was not associated with hemoglobin variability.

Conclusions

Maintenance hemodialysis patients on ESA treatment with higher hemoglobin variability are at higher risk for all-cause mortality and particularly infectious events.

Cognitive disorders in patients with chronic kidney disease: Approaches to prevention and treatment

BACKGROUND

Cognitive impairment is common in patients with chronic kidney disease (CKD), and early intervention may prevent the progression of this condition.

METHODS

Here, we review interventions for the complications of CKD (anemia, secondary hyperparathyroidism, metabolic acidosis, harmful effects of dialysis, the accumulation of uremic toxins) and for prevention of vascular events, interventions that may potentially be protective against cognitive impairment. Furthermore, we discuss nonpharmacological and pharmacological methods to prevent cognitive impairment and/or minimize the latter's impact on CKD patients' daily lives.

RESULTS

A particular attention on kidney function assessment is suggested during work-up for cognitive impairment. Different approaches are promising to reduce cognitive burden in patients with CKD but the availabe dedicated data are scarce.

CONCLUSIONS

There is a need for studies assessing the effect of interventions on the cognitive function of patients with CKD.

Unresolved aspects in the management of renal anemia, a Delphi consensus of the Anemia Group of the S.E.N

Anemia is a common complication of chronic kidney disease (CKD) and is associated with a decrease in quality of life and an increased risk of transfusions, morbidity and mortality, and progression of CKD. The Anemia Working Group of the Sociedad Española de Nefrología conducted a Delphi study among experts in anemia in CKD to agree on relevant unanswered questions by existing evidence. The RAND/UCLA consensus methodology was used. We defined 15 questions with a PICO structure, followed by a review in scientific literature databases. Statements to each question were developed based on that literature review. Nineteen experts evaluated them using an iterative Two-Round Delphi-like process. Sixteen statements were agreed in response to 8 questions related to iron deficiency and supplementation with Fe (impact and management of iron deficiency with or without anemia, iron deficiency markers, safety of i.v. iron) and 7 related to erythropoiesis stimulating agents (ESAs) and/or hypoxia-inducible factor stabilizers (HIF), reaching consensus on all of them (individualization of the Hb objective, impact and management of resistance to ESA, ESA in the immediate post-transplant period and HIF stabilizers: impact on ferrokinetics, interaction with inflammation and cardiovascular safety). There is a need for clinical studies addressing the effects of correction of iron deficiency independently of anemia and the impact of anemia treatment with various ESA on quality of life, progression of CKD and cardiovascular events.

Epidemiology and treatment of renal anaemia in Spain: RIKAS retrospective study

BACKGROUND AND OBJECTIVE

Studies on the prevalence of anaemia in chronic kidney disease in adults not on dialysis (CKD-ND) and in dialysis programmes (CKD-D) in Spain are not recent or focus on certain subgroups. The aim of this study was to know the epidemiology and current treatment patterns of anaemia associated with CKD in Spain.

MATERIALS AND METHODS

Multicentre, non-interventional, retrospective study with CKD-ND stage 3a-5 and CKD-D patients treated in Spain between 2015 and 2017 (RIKAS study).

RESULTS

The prevalence of anaemia in CKD-ND and CKD-D in 2015 was 33.8% and 91.5%, respectively, with similar results during 2016-2017. The prevalence of systemic inflammation in anaemic patients (18.1% and 51.8% for CKD-ND and CKD-D, respectively) was higher, especially in those treated with erythropoiesis-stimulating agents (ESA), compared to the general population with CKD-ND. After 12 months of follow-up, mean ferritin and transferrin saturation index (TSI) values in anaemic patients with CKD-ND were 187.1 ng/mL and 22.2%, respectively, while in CKD-D were 254.6 ng/mL and 20.2%. In ESA-treated patients, mean values were 190.6 ng/mL and 22.0% in ND-CKD, and 255.0 ng/mL and 20.2% in D-CKD.

CONCLUSIONS

The prevalence of anaemia and inflammation increased with the disease severity, being higher in D-CKD. Iron parameters in anaemic patients treated or not with ESA are insufficient according to the guidelines, so there is room for improvement in the treatment of anaemia associated with CKD.

Serum iron levels in tuberculosis patients and household contacts and its association with natural resistance-associated macrophage protein 1 polymorphism and expression

BACKGROUND

Iron deficiency can impair immune function, increasing tuberculosis (TB) susceptibility and severity. The research aimed to investigate iron deficiency anemia in TB patients and household contacts and its association with natural resistance-associated macrophage protein 1 (NRAMP1) polymorphism and expression.

METHODS

The levels of iron, ferritin, and transferrin were measured in the serum by ELISA (Enzyme-Linked Immunosorbent Assay). NRAMP1 polymorphisms were determined by polymerase chain reaction (PCR) and sequencing. NRAMP1 gene expression was measured by real-time PCR. Interferon-gamma release assay (IGRA) checked on household contacts to screen household contacts with positive IGRA as the control.

RESULTS

This study involved 35 TB cases and 35 TB contacts. The results showed that the serum Fe levels were found to be lower in the TB case group (median 149.6 μmol/L) than in the positive IGRA household contacts group (median 628.53 μmol/L) with a p-value <0.001. Meanwhile, ferritin levels in TB cases tended to be higher, in contrast to transferrin, which was found to tend to be lower in TB cases than household contacts but did not show a significant difference. This study found no association between the polymorphism of exon 15 D543 and active TB. However, NRAMP1 gene expression was lower in TB cases than in positive IGRA household contacts (p = 0.011). Besides, there was a positive correlation between NRAMP1 gene expression and serum Fe levels (r = 0.367, p = 0.006). TB was associated with decreased NRAMP1 gene expression (OR 0.086 95% CI 0.02-0.366, p = 0.001). Besides, TB was associated with low Fe levels (OR 0.533 95% CI 0.453-0.629, p < 0.001).

CONCLUSION

Comparing the TB case to the household contacts group, decreased serum Fe levels were discovered in the TB case group. This study also shows a correlation of NRAMP1 gene expression to Fe levels in TB patients and household contacts and describes that TB may lead to decreased Fe levels by downregulating NRAMP1 expression.

Precision Medicine in Erythropoietin Deficiency and Treatment Resistance: A Novel Approach to Management of Anaemia in Chronic Kidney Disease

The study of anaemia is a well-developed discipline where the concepts of precision medicine have, in part, been researched extensively. This review discusses the treatment of erythropoietin (EPO) deficiency anaemia and resistance in cases of chronic kidney disease (CKD). Traditionally, erythropoietin-stimulating agents (ESAs) and iron supplementation have been used to manage anaemia in cases of CKD. However, these treatments pose potential risks, including cardiovascular and thromboembolic events. Newer treatments have emerged to address these risks, such as slow-release and low-dosage intravenous iron, oral iron supplementation, and erythropoietin-iron combination therapy. Another novel approach is the use of hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs). This review highlights the need for precision medicine targeting the genetic components of EPO deficiency anaemia in CKD and discusses individual variability in genes such as the erythropoietin gene (EPO), the interleukin-β gene (IL-β), and the hypoxia-inducible factor gene (HIF). Pharmacogenetic testing aims to provide targeted therapies and interventions that are tailored to the specific characteristics of an individual, thus optimising treatment outcomes and minimising resistance and adverse effects. This article concludes by suggesting that receptor modification has the potential to revolutionise the treatment outcomes of patients with erythropoietin deficiency anaemia through the integration of the mentioned approach.

Iron-Deficiency Anemia in CKD: A Narrative Review for the Kidney Care Team

Anemia is a common complication of chronic kidney disease (CKD) and is associated with increased mortality and reduced health-related quality of life. Anemia is characterized by a decrease in hemoglobin, the iron-rich protein that the body uses for oxygen transport. Iron is required to produce hemoglobin, and disruptions in the iron homeostasis can lead to iron-deficiency anemia. Management of anemia in individuals with CKD is typically performed by a team of physicians, nurse practitioners, physician assistants, or registered nurses. Throughout the care continuum, the management can be enhanced by multidisciplinary care, and individuals with CKD can benefit from the involvement of other specialties, with dietitians/nutritionists playing an important role. However, a key area of unmet clinical need is how to assess and address iron-deficiency anemia. This review aims to provide an overview of iron-deficiency anemia in CKD and how this may be diagnosed and managed by the entire kidney care team, such as describing the mechanisms underlying iron homeostasis, the complications of iron-deficiency anemia, and the current challenges associated with its diagnosis and treatment in CKD. Opportunities for each multidisciplinary team member to add value to the care of individuals with CKD and iron-deficiency anemia are also described.

Safety Endpoints With Vadadustat Versus Darbepoetin Alfa in Patients With Non-Dialysis-Dependent CKD: A Post Hoc Regional Analysis of the PRO2TECT Randomized Clinical Trial of ESA-Naïve Patients

Rationale & Objective

Prespecified analyses of the PRO2TECT trials comparing the safety of the oral hypoxia-inducible factor prolyl hydroxylase inhibitor vadadustat with darbepoetin alfa in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) found no difference in major adverse cardiovascular events (MACE; death from any cause or nonfatal myocardial infarction or stroke) among US patients and a higher risk among patients treated with vadadustat outside the United States. We investigated regional differences in MACE in the PRO2TECT trial that enrolled 1,751 patients previously untreated with erythropoiesis-stimulating agents.

Study Design

Phase 3, global, open-label, randomized, active-controlled clinical trial.

Setting and Participants

Erythropoiesis-stimulating agent-untreated patients with anemia and NDD-CKD.

Intervention

Eligible patients were randomized 1:1 to receive vadadustat or darbepoetin alfa.

Outcomes

The primary safety end point was time to first MACE. Secondary safety end points included time to first expanded MACE (MACE plus hospitalization for heart failure or thromboembolic event, excluding vascular access thrombosis).

Results

In the non-US/non-Europe region, there was a higher proportion of patients with baseline estimated glomerular filtration rate (eGFR) level of ≤10 mL/min/1.73 m2 in the vadadustat group [96 (34.7%)] than in the darbepoetin alfa group [66 (24.0%)]. In this region, there were 21 excess MACEs reported in the vadadustat group [78 events (n=276)] versus the darbepoetin alfa [57 events (n=275)], including 13 excess noncardiovascular deaths, largely from kidney failure. Noncardiovascular deaths were concentrated in Brazil and South Africa, which enrolled higher proportions of patients with an eGFR of ≤10 mL/min/1.73 m2 and who may not have had access to dialysis.

Limitations

Different regional treatment patterns of patients with NDD-CKD.

Conclusions

The higher MACE rate in the non-US/non-Europe vadadustat group may have been partly because of imbalances in the baseline eGFR level in countries where dialysis was not uniformly available resulting in many kidney-related deaths.

Cardiovascular safety of current and emerging drugs to treat anaemia in chronic kidney disease: a safety review

INTRODUCTION

Erythropoiesis-stimulating agents (ESAs) are the standard of treatment for anemia in chronic kidney disease. Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHI) are small molecules that stimulate endogenous erythropoietin synthesis.

AREAS COVERED

The cardiovascular safety of ESAs and HIF-PHIs. We performed a PubMed search using several key words, including anemia, chronic kidney disease, safety, erythropoiesis stimulating agents, HIF-PH inhibitors.

EXPERT OPINION

ESAs are well-tolerated drugs with a long history of use; there are safety concerns, especially when targeting high hemoglobin levels. HIF-PHIs have comparable efficacy to ESAs in correcting anemia. Contrary to expectations, randomized phase 3 clinical trials have shown that overall HIF-PHIs were non-inferior to ESA or placebo with respect to the risk of cardiovascular endpoints. In addition, some phase 3 trials raised potential safety concerns regarding cardiovascular and thrombotic events, particularly in non-dialysis patients.Today, HIF-PHIs represent an additional treatment option for anemia in patients with chronic kidney disease. This has made the management of anemia in CKD more complex and heterogeneous. A better understanding of the mechanisms causing hypo-responsiveness to ESAs, combined with an individualized approach that balances ESAs, HIF-PHIs and iron doses, could increase the benefits while reducing the risks.

Iron Parameters in Patients Treated with Roxadustat for Anemia of Chronic Kidney Disease

Roxadustat is a novel agent with a distinct mechanism of action compared to erythropoiesis-stimulating agents (ESAs) and a potentially different combination of effects on iron parameters. This narrative review describes the effects of roxadustat on iron parameters and on hemoglobin levels in the context of iron supplementation in patients with anemia of non-dialysis-dependent (NDD) or dialysis-dependent (DD) chronic kidney disease (CKD). Roxadustat use was associated with a greater reduction in serum ferritin levels than seen with ESAs and an increase in serum iron levels compared to a decrease with ESAs. Decreases in transferrin saturation in patients treated with roxadustat were relatively small and, in the case of patients with NDD CKD, not observed by Week 52. These changes reflect the concomitant increases in both serum iron and total iron-binding capacity. Compared to placebo and an ESA, roxadustat improved iron availability and increased erythropoiesis while requiring less intravenous iron use. Hepcidin levels generally decreased in patients who received roxadustat compared to baseline values in all CKD populations; these decreases appear to be more robust with roxadustat than with an ESA or placebo. The mechanisms behind the effects of roxadustat and ESAs on iron availability and stores and erythropoiesis appear to differ and should be considered holistically when treating anemia of CKD.

Nutritional Treatment as a Synergic Intervention to Pharmacological Therapy in CKD Patients

Nutritional and pharmacological therapies represent the basis for non-dialysis management of CKD patients. Both kinds of treatments have specific and unchangeable features and, in certain cases, they also have a synergic action. For instance, dietary sodium restriction enhances the anti-proteinuric and anti-hypertensive effects of RAAS inhibitors, low protein intake reduces insulin resistance and enhances responsiveness to epoetin therapy, and phosphate restriction cooperates with phosphate binders to reduce the net phosphate intake and its consequences on mineral metabolism. It can also be speculated that a reduction in either protein or salt intake can potentially amplify the anti-proteinuric and reno-protective effects of SGLT2 inhibitors. Therefore, the synergic use of nutritional therapy and medications optimizes CKD treatment. Quality of care management is improved and becomes more effective when compared to either treatment alone, with lower costs and fewer risks of unwanted side effects. This narrative review summarizes the established evidence of the synergistic action carried out by the combination of nutritional and pharmacological treatments, underlying how they are not alternative but complementary in CKD patient care.

Managing Anemia: Point of Convergence for Heart Failure and Chronic Kidney Disease?

The pathologic triangle formed by chronic heart failure (HF), chronic kidney disease (CKD), and anemia carries high morbidity and mortality rates and decreases quality of life. Anemia represents a common condition in patients with advanced HF and CKD, with a total prevalence in cardiorenal syndrome (CRS) ranging from 5% to 55%. Searching for a pragmatic approach for these patients with guided and disease-specific recommendations beyond just targeted hemoglobin therapeutic behavior represents the core of research for ongoing clinical trials. It is well known that the prevalence of anemia increases with the advancement of CKD and HF. The physiopathological mechanisms of anemia, such as the reduction of endogenous erythropoietin and the decrease in oxygen transport, are leading to tissue hypoxia, peripheral vasodilation, stimulating neurohormonal activity, and maintenance of the progressive renal and cardiac dysfunction. Given the challenges with the treatment options for patients with cardiorenal anemia syndrome (CRSA), new therapeutic agents such as hypoxia-inducible factor-prolyl hydroxylase domain inhibitors (HIF-PH) or hepcidin antagonists are emerging in the light of recent research. This review summarizes the potential therapeutic tools for anemia therapy in the cardiorenal population.