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

Quality of life: a crucial aspect for the patients, a neglected goal in the treatment of anemia in patients with CKD

The aim of any treatment should be to add life to years and not simply years to life. Surprisingly, the label of erythropoiesis-stimulating agents for anemia treatment in chronic kidney disease does not include the indication for improving quality of life. Merit of the placebo-controlled Anemia Studies in Chronic Kidney Disease (CKD): Erythropoiesis Via a Novel Prolyl Hydroxylase Inhibitor (PHI) Daprodustat in Non-Dialysis Subjects Evaluating Hemoglobin (Hgb) and Quality of Life (ASCEND-NHQ) trial was to address this issue by analyzing the effect of anemia treatment with daprodustat aimed at the hemoglobin target range of 11-12 g/dl; the trial demonstrates that partial anemia correction improved quality of life.

Therapeutics of managing reduced red cell mass associated with chronic kidney disease - Is there a case for earlier intervention?

Reduced red cell mass is a poor prognostic indicator in chronic kidney disease (CKD) patients. Whilst overt anaemia impacts on the quality of life of patients with CKD, lowered red cell mass may also compromise oxygen delivery to proximal tubular cells and contribute to progressive kidney injury. Epidemiological data from cats with CKD support this hypothesis although controlled interventional studies involving drugs that raise red cell mass in trials designed to test this hypothesis are lacking in both human and veterinary medicine. Recombinant analogues of erythropoietin (EPO) are currently standard of care for human CKD patients where low red cell mass impacts on their quality of life. Resistance to EPO is encountered in 20% to 40% of patients treated, probably due to functional iron deficiency, reflecting the difficulties of managing iron deficiency associated with the chronic inflammation of CKD. Similar issues are likely faced in managing anaemia in feline CKD although published data on the use of human EPO analogues are limited as such treatment in cats risks antibody formation resulting in red cell aplasia and transfusion dependency and so is reserved for late stage cases only. This article reviews the recent alternative therapeutic approach to increase red cell mass using HIF-prolyl hydroxylase inhibitors and explains their mode of action and theoretical advantages over EPO analogues in the context of iron metabolism. The results of human clinical trials and the potential benefit of adopting this approach in feline CKD patients are discussed.

Efficiency of ferric carboxymaltose in non-dialysis CKD patients and its impact on kidney function: a prospective observational study

BACKGROUND

Iron deficiency anemia occurs in most patients with non-dialysis chronic kidney disease (ND-CKD). Previous studies have suggested that intravenous (IV) iron therapy is more effective than oral iron in these patients. Clinical evidence relating the effects of IV iron on renal function is, however, limited.

METHODS

Prospective observational study of adult patients with ND-CKD, anemia, iron deficiency, and estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m², treated with a single dose of 500 mg or 1000 mg of ferric carboxymaltose (FCM) and followed-up for 24 weeks. Primary outcome was FCM efficacy, assessed by comparing Hb, TSAT and ferritin at 24 weeks with those at baseline. Secondary outcome was FCM impact on renal function, evaluated by comparing eGFR over the same period.

RESULTS

One hundred and forty patients were recruited: seventy-eight (55.7%) were treated with 1000 mg and 62 (44.3%) with 500 mg of FCM. 24 weeks after FCM administration, Hb increased 1.54 ± 1.99 g/dL (95% CI 1.09-1.99, p = 001) in the group treated with 1000 mg and 0.86 ± 1.4 g/dL (95% CI 0.53-1.22, p = 0.001) in those treated with 500 mg. TSAT increased in both groups but more in those treated with 1000 mg, and ferritin only increased in the latter. Estimated GFR showed a significant increase of 1.55 ± 6.86 mL/min/m² (95% CI 0.05-3.09, p = 0.049), from a baseline of 27.73 ± 17.23 to 28.88 ± 18.02 mL/min/m² in the group treated with 1000 mg.

CONCLUSIONS

Our findings suggested that IV FCM therapy was effective in improving serum iron levels and anemia in ND-CKD stage 3 to 5 patients. Higher doses seem to be necessary to replace depleted iron stores. In our cohort, IV FCM therapy was associated with an improvement in renal function, particularly in those treated with higher doses of FCM.

Prevalence, incidence, and treatment of anaemia in patients with non-dialysis-dependent chronic kidney disease: findings from a retrospective real-world study in Italy

BACKGROUND

Limited data are available on the epidemiology and clinical management of anaemia in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD).

METHODS

This retrospective observational study was based on records from databases of five Local Health Units across Italy. Adults with reported NDD-CKD stage 3a-5 between 1 January 2014 and 31 December 2016 were identified. Annual prevalence and incidence of anaemia (age- and sex-standardised) and clinical management (erythropoiesis-stimulating agents [ESAs], intravenous [IV] iron, and blood transfusions) were evaluated. Eligibility for ESAs was defined by ≥ 2 records of Hb < 10 g/dL, or < 11 g/dL over 6 months.

RESULTS

Overall, 101,143 individuals with NDD-CKD (3a-5) recorded between 2014 and 2016 were identified, of whom 40,020 (39.6%) were anaemic. Prevalence of anaemia was 33.8% in 2016 and incidence of anaemia was stable (11.4-12.4%) from 2014 to 2016. Prevalence and incidence of anaemia increased with CKD stage. Among eligible patients, 12.8% with Hb < 11 g/dL and 15.5% with Hb < 10 g/dL received ESAs, and the proportion treated increased with CKD stage. Among ESA-treated patients with at least 2 years of follow up, 18.4% and 19.3% received IV iron in the Hb < 11 and < 10 g/dL groups, respectively, and 16.5% and 19.4% received blood transfusions. Corresponding proportions for the overall anaemic cohort were 9.0% and 11.3%, respectively.

CONCLUSIONS

Anaemia is a significant issue in patients with NDD-CKD. Low rates of ESA treatment indicate a potential treatment gap and suggest that anaemia may not be adequately controlled in many patients.

[Anemia and quality of life of chronic kidney disease patients on renal replacement therapy by programmed hemodialysis]

AIM

To study relationship between anemia and health-related quality of life (HRQOL) of chronic kidney disease stage 5 patients (CKD) undergoing renal replacement therapy by programmed hemodialysis.

MATERIALS AND METHODS

The study was conducted on the basis of dialysis centers/departments in Moscow. The Russian-language version of the KDQOL-SF^TM questionnaire, validated in Russia, was used to assess the HRQOL of patients on hemodialysis. A total of 723 patients were interviewed. Hemoglobin (Hb) levels were assessed in 442 patients based on outpatient records. To identify the relationship between Hb level and HRQOL scales, a correlation analysis was performed, as well as a HRQOL analysis in the three groups differing in hemoglobin levels (<100; 100-120 and >120 g/l). Statistical data processing was carried by SPSS.22 and using parametric and nonparametric statistical methods.

RESULTS

Correlation relationship was revealed between Hb and HRQOL of patients on hemodialysis on the scales "symptoms/problems", "pain", "vital activity, energy" and "total physical component of health". According to the scales "symptoms/problems" and "vital activity, energy", higher rates were noted among patients with Hb higher than the target level, which confirms the recommendations concerning the possibility of achieving higher Hb among individual patients who have not serious concomitant diseases and cardiovascular complications in order to improve their quality of life.

CONCLUSION

HRQOL assessment is important tool for planning and evaluating the effectiveness of anemia drug therapy among patients with CKD on hemodialysis.

Evaluation of Hemoglobin Response to Treatment With Enarodustat Using Pharmacometric Approach in Japanese Anemic Patients With Chronic Kidney Disease

Enarodustat (JTZ-951) is a hypoxia-inducible factor prolyl hydroxylase inhibitor that has been approved and marketed in Japan for patients with anemia with chronic kidney disease (CKD). The pharmacometric approach was applied to assess the relationship between plasma concentrations of enarodustat and hemoglobin (Hb) levels, and to provide information regarding the optimal use of enarodustat in clinical practice by simulations based on the pharmacokinetic and pharmacodynamic (PK/PD) model that was developed. The PK/PD data of enarodusat obtained from phase 2 and phase 3 studies in Japanese patients with CKD were well described by the models: a 1-compartment model with first-order absorption and elimination for PK, and a semimechanistic model based on transit compartment model for PD. Although several factors were identified as statistically significant covariates on the PK/PD of enarodustat, model-based simulations showed that none of them had clinically relevant impacts on the treatment effect (ie, Hb levels) of enarodustat. Hence, enarodustat treatment provides the stable Hb control with the initial dose (hemodialysis-dependent CKD: 4 mg/day, non-dialysis-dependent CKD: 2 mg/day) and maintenance dose (1-8 mg/day) to the patients with varied demographic characteristics.

How to diagnose iron deficiency in chronic disease: A review of current methods and potential marker for the outcome

Iron deficiency (ID) is the most common nutritional disorder worldwide. It is often observed in patients with chronic diseases, such as heart failure (HF), chronic kidney disease (CKD), inflammatory bowel disease (IBD) and cancer. ID is associated with poor clinical outcome, including poor performance, reduced quality of life, as well as increased hospitalization and mortality. The aim of this review is to provide an overview about the role of ID in chronic diseases (HF, CKD, IBD, cancer) regarding their current definitions and clinical relevance; diagnostic accuracy of iron parameters in chronic inflammatory conditions and its potential as prognostic markers. Due to different definitions and guideline recommendations of ID, various laboratory parameters for ID diagnostic exist and there is no general consensus about the definition of ID and its treatment. Still, a general trend can be observed across all investigated indications of this review (HF, CKD, IBD, cancer) that serum ferritin and transferrin saturation (TSAT) are the two parameters mentioned most often and emphasized in all guidelines to define ID and guide treatment. The most commonly used threshold values for the diagnosis of ID are TSAT of < 20% and serum ferritin of < 100-300 µg/L. Noteworthy, both TSAT and particularly ferritin are frequently applied, but both may vary due to inflammatory conditions. Studies showed that TSAT is less affected by inflammatory processes and may therefore be more accurate and reliable than serum ferritin, particularly in conditions with elevated inflammatory state. A low iron status and particularly a low TSAT value was associated with a poor outcome in all investigated indications, with the strongest evidence in HF patients. Routine surveillance of iron status in these groups of patients with chronic conditions is advisable to detect ID early. Depending on the inflammatory state, TSAT < 20% may be the more accurate diagnostic marker of ID than ferritin. Moreover, TSAT may also be the more reliable estimate for the prognosis, particularly in HF.

Effects of hypoxia-inducible factor-prolyl hydroxylase inhibitors vs. erythropoiesis-stimulating agents on iron metabolism in non-dialysis-dependent anemic patients with CKD: A network meta-analysis

OBJECTIVE

To compare the effects of five hypoxia-inducible factor-prolyl hydroxylase domain inhibitors (HIF-PHIs), two erythropoiesis-stimulating agents (ESAs), and placebo on iron metabolism in renal anemia patients with non-dialysis-dependent chronic kidney disease (NDD-CKD).

METHOD

Five electronic databases were searched for studies. Randomized controlled clinical trials comparing HIF-PHIs, ESAs, and placebo in NDD-CKD patients were selected. The statistical program used for network meta-analysis was Stata/SE 15.1. The main outcomes were the change in hepcidin and hemoglobin (Hb) levels. The merits of intervention measures were predicted by the surface under the cumulative ranking curve method.

RESULTS

Of 1,589 original titles screened, data were extracted from 15 trials (3,228 participants). All HIF-PHIs and ESAs showed greater Hb level-raising ability than placebo. Among them, desidustat demonstrated the highest probability of increasing Hb (95.6%). Hepcidin [mean deviation (MD) = -43.42, 95%CI: -47.08 to -39.76], ferritin (MD= -48.56, 95%CI: -55.21 to -41.96), and transferrin saturation (MD = -4.73, 95%CI: -5.52 to -3.94) were decreased, while transferrin (MD = 0.09, 95%CI: 0.01 to 0.18) and total iron-binding capacity (MD = 6.34, 95%CI: 5.71 to 6.96) was increased in HIF-PHIs versus those in ESAs. In addition, this study observed heterogeneity in the ability of HIF-PHIs to decrease hepcidin. Compared with darbepoetin, only daprodustat (MD = -49.09, 95% CI: -98.13 to -0.05) could significantly reduce hepcidin levels. Meanwhile, daprodustat also showed the highest hepcidin-lowering efficacy (84.0%), while placebo was the lowest (8.2%).

CONCLUSION

For NDD-CKD patients, HIF-PHIs could ameliorate functional iron deficiency by promoting iron transport and utilization, which may be achieved by decreasing hepcidin levels. Interestingly, HIF-PHIs had heterogeneous effects on iron metabolism.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=242777, Identifier CRD42021242777.

Low-Dose Oral Iron Replacement Therapy Is Effective for Many Japanese Hemodialysis Patients: A Retrospective Observational Study

Western guidelines recommend the use of intravenous iron supplementation for hemodialysis patients. However, in Japanese patients with well-controlled inflammation, iron replacement may be achieved with oral iron supplementation. This study involved 108 courses in 77 outpatient hemodialysis patients who received low-dose oral iron replacement therapy. Data from baseline to week 28 of treatment were analyzed to identify factors associated with effectiveness. Changes over time in erythrocyte- and iron-related parameters and erythropoiesis-stimulating agent (ESA) dose were investigated in the effective group. A total of 84 courses (77.8%) satisfied the effectiveness criteria. Compared with the effective and ineffective groups, only C-reactive protein (CRP) was significantly different (p < 0.01). ROC curve analysis with efficacy as the endpoint showed a CRP cut point value of ≤0.1 mg/dL (area under the curve, 0.69; 95% confidence interval, 0.57−0.81). The relationship between serum ferritin and hemoglobin fluctuation by reducing the ESA dose showed a positive correlation (p < 0.001). In the ESA maintenance group, the serum ferritin gradually increased and then remained constant at about 60 ng/mL. Our data suggest that patients with CRP ≤ 0.1 mg/dL may benefit from low doses of oral iron supplementation. Approximately 60 ng/mL serum ferritin may be sufficient during stable hematopoiesis.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

[Management of iron deficiency in chronic kidney disease: Review and proposed algorithm]

Iron deficiency is very common in chronic kidney disease, even before the dialysis stage. It is an independent factor of morbidity and mortality in patients with non-dialysis chronic kidney disease. During chronic kidney disease, iron deficiency is defined by a transferrin saturation <20% and/or a serum ferritin <100 μg/L. In France, about half of non-dialysis chronic kidney disease patients have absolute iron deficiency (transferrin saturation <20% and serum ferritin <100 μg/L) and/or functional iron deficiency (transferrin saturation <20% and serum ferritin >100 μg/L). Despite this, iron deficiency is usually not investigated. In fact, more than 60% of nephrologists do not assess iron status at least once a year. In addition, iron deficiency is rarely treated: only 12% of patients are prescribed oral or intravenous iron. Early detection and treatment are fundamental and should be systematic. In order to help improve the management of iron deficiency among non-dialysis chronic kidney disease patients, we propose an algorithm that takes into account current recommendations and the most recent data from the literature. Initial blood test requires the measurement of hemoglobin concentration, transferrin saturation and serum ferritin. A transferrin saturation <20% establishes the diagnosis of iron deficiency and the serum ferritin level points towards an absolute or functional deficiency. The combination of both values makes it possible to adapt the treatment, particularly in an inflammatory context where oral iron is not effective.

Management of anaemia in French dialysis patients: results from a large epidemiological retrospective study

Background

Limited real-world data are available in Europe, especially France, regarding the therapeutic management of anaemia in patients with dialysis-dependent chronic kidney disease (DD CKD).

Methods

This retrospective, longitudinal, observational study was based on medical records from the MEDIAL database of not-for-profit dialysis units in France. From January to December 2016, we included eligible patients (≥18 years), with a diagnosis of CKD and receiving maintenance dialysis. Patients with anaemia were followed up for 2 years after inclusion. Patient demographic data, anaemia status, CKD-related anaemia treatments, and treatment outcomes including laboratory test results were evaluated.

Results

Of 1632 DD CKD patients identified from the MEDIAL database, 1286 had anaemia; 98.2% of patients with anaemia were receiving haemodialysis at index date (ID). Of patients with anaemia, 29.9% had haemoglobin (Hb) levels of 10-11 g/dL and 36.2% had levels of 11-12 g/dL at ID. Furthermore, 21.3% had functional iron deficiency and 11.7% had absolute iron deficiency. The most commonly prescribed treatments at ID for patients with DD CKD-related anaemia were intravenous (IV) iron with erythropoietin-stimulating agents (ESAs) (65.1%). Among patients initiating ESA treatment at ID or during follow-up, 347 (95.3%) reached the Hb target of 10-13 g/dL and maintained response within the target Hb range for a median duration of 113 days.

Conclusions

Despite combined use of ESAs and IV iron, duration within the Hb target range was short, suggesting that anaemia management can be further improved.

Hypoxia-Inducible Factor-Prolyl Hydroxyl Domain Inhibitors: From Theoretical Superiority to Clinical Noninferiority Compared with Current ESAs?

Anemia is a common complication of chronic kidney disease; it is mainly treated with erythropoiesis-stimulating agents (ESAs) and iron. Experimental studies extensively investigated the mechanisms involved in the body's response to hypoxia and led to the discovery of the hypoxia-inducible factor (HIF) pathway and the enzymes regulating its function. HIF-prolyl-hydroxyl domain (PHD) inhibitors are a new class of oral drugs developed to treat anemia in chronic kidney disease. By inhibiting the function of PHD enzymes, they mimic the exposure to moderate hypoxia and stimulate the production of endogenous erythropoietin and very likely increase iron availability. Some data also suggest that their efficacy and, consequently, dose needs are less influenced by inflammation than ESAs. Overall, data from phases 2 and 3 clinical development showed efficacy in anemia correction and maintenance for all of the class molecules compared with placebo (superiority) or erythropoiesis-stimulating agents (noninferiority). Three molecules, roxadustat, vadadustat, and daprodustat, underwent extensive clinical investigation to assess their safety on hard cardiovascular end points, mortality, and special interest events (including cancer and thrombosis). Aside from vadadustat in the nondialysis population, at the prespecified primary analyses, all three molecules met the noninferiority margin for the risk of major cardiovascular events compared with erythropoiesis-stimulating agents or placebo. The reason for this discrepancy is difficult to explain. Other safety signals came from secondary analyses of some of the other randomized clinical trials, including a higher incidence of thrombosis. A more extensive clinical experience with post-marketing data on hard safety issues is needed to define better when and how to use HIF-PHD inhibitors compared with already available ESAs.

Effects of Zinc Acetate Hydrate Supplementation on Renal Anemia with Hypozincemia in Hemodialysis Patients

INTRODUCTION AND AIMS

This study examined whether zinc supplementation with zinc acetate hydrate improved renal anemia with hypozincemia in patients undergoing hemodialysis.

METHODS

The study participants included 21 patients undergoing hemodialysis who presented with a serum zinc level < 60 mg/dL and who were administered zinc acetate hydrate at 50 mg (reduced to 25 mg, as appropriate) for 6 months. Patients with a hemorrhagic lesion, acute-phase disease (pneumonia or cardiac failure), or hematologic disease and those whose treatment was switched from peritoneal dialysis to hemodialysis were excluded. The changes in the erythropoietin resistance index (ERI) before and after zinc acetate hydrate administration were examined. ERI was defined as the dose (IU) of erythropoiesis-stimulating agent (ESA)/week/body weight (kg)/hemoglobin content (g/dL). The differences between the two groups were analyzed using the Wilcoxon signed rank sum test, and p < 0.05 was considered statistically significant.

RESULTS

The study participants included 19 men and 2 women aged 41-95 years (mean ± standard deviation (SD): 67.1 ± 13.6). The changes in the values of parameters measured before and after zinc acetate hydrate administration were as follows: Blood Hb did not change significantly, from 10.0-13.6 g/dL (11.5 ± 1.0 g/dL) to 10.2-12.4 g/dL (11.4 ± 0.7 g/dL); serum zinc concentration significantly increased, from 33.0-59.0 mg/dL μg/dL (52.4 ± 7.6 mg/dL μg/dL) to 57.0-124.0 mg/dL μg/dL (84.1 ± 16.3 mg/dL μg/dL; p < 0.01); the ESA dose significantly decreased, from 0-12,000 IU/week (5630 ± 3351 IU/week) to 0-9000 IU/week (4428 ± 2779; p = 0.04); and ERI significantly decreased, from 0.0-18.2 (8.1 ± 5.1) to 0.0-16.0 (6.3 ± 4.3; p = 0.04).

CONCLUSIONS

Zinc supplementation increased the serum zinc concentration and significantly reduced the ESA dose and ERI, suggesting that a correction of hypozincemia contributes to lessening renal anemia in these patients.

Anemia and iron in internal medicine: an Italian survey and a review on iron intravenous therapy in medical patients

In Italy, Internal Medicine Units hospitalize approximately 1,300,000 patients, often elderly and comorbid. The prevalent diagnoses are respiratory diseases, heart failure, or pneumonia. As a matter of fact, anemia is probably underestimated in the compilation of the official discharge forms (SDO) according to ICD-9 diagnostic codes. We promoted a survey among the Members the Italian Scientific Society of Internal Medicine (FADOI) with the aim to investigate the prevalence of anemia and iron deficiency, over than certain aspects related to the therapeutic management of patients with anemia. Furthermore, we performed a review summarizing current evidence for iron intravenous therapy in these patients. According to the survey, anemia is present in around half of the patients hospitalized in Internal Medicine, and about a quarter of them shows iron metabolism alterations. In the evaluation of iron metabolism, the dosage of ferritin is the most requested exam, whereas transferrin saturation is less considered. By focusing on some categories of patients, the awareness of the usefulness of intravenous iron therapy in patients with heart failure seems to be sufficiently common (76% of physicians), while it seems lower (60%) in the management of patients with chronic kidney disease (CKD) and anemia. Finally, more than 75% of the physicians answered that, in their hospital, there are few outpatients’ offices or diagnostic pathways dedicated to patients with anemia. Anemia due to absolute or functional iron deficiency is particularly prevalent in Internal Medicine inpatients. For this reason, an accurate evaluation of iron profile and an adequate iron therapy is mandatory in these patients. Recent studies show that, in patients with heart failure, intravenous iron therapy is an effective way of improving patients’ health, regardless of the presence of anemia. Similarly, iron therapy results fundamental to optimize erythropoiesis-stimulating agent efficacy in patients with chronic renal failure. In the next future, other therapeutic aspects of intravenous iron therapy will be probably clarified by several interesting ongoing studies focused on these patients.

Ferritin and its association with anaemia in a healthy adult population in Kenya

BACKGROUND

Iron deficiency is the commonest cause of anaemia worldwide. Serum ferritin is the most sensitive non-invasive indicator of iron stores but its utility is compromised in inflammatory states as it is an acute phase reactant. This study sought to estimate the burden of iron deficiency in a healthy adult population residing in Kenya and to determine the association between various ferritin cut-offs and anaemia in a population known to have chronic low-grade inflammation.

METHODS

Healthy adults aged 18-65 years were recruited from urban towns in 4 counties in Kenya at average altitudes of 1683-2099m above sea level as part of a global study conducted by the International Federation of Clinical Chemistry (IFCC) to determine reference intervals (RIs) for common laboratory tests. We analyzed complete blood count (CBC), C-reactive protein, iron, transferrin, transferrin saturation and ferritin data.

RESULTS

We obtained data from 528 participants. There were 254 (48.1%) males and 274 females (51.9%). Based on a ferritin cut-off of 15 μg/L and Hb cut-offs of 14.5 g/dL and 12 g/dL, the prevalence of iron deficiency anaemia was 0.8% and 7.3% in males and females respectively. The odds of having anaemia was highest if one had a ferritin value less than 15 μg/L with a sensitivity of 28.6% and specificity of 98.4% in males, and sensitivity of 83.3% and specificity of 78.0% in females.

CONCLUSION

Only the ferritin cut-off of 15 ug/L had an association with anaemia where it can be used for ruling out iron deficiency as the cause. Sex specific ferritin cut-offs for diagnosing iron deficiency in adults in sub-Saharan Africa need to be derived by comparing ferritin levels to stainable iron in bone marrow aspirates and trephines in order to ensure that we are using appropriate clinical decision limits.

Adherence to multidisciplinary care in a prospective chronic kidney disease cohort is associated with better outcomes

INTRODUCTION

The Renal Healthcare Program Uruguay (NRHP-UY) is a national, multidisciplinary program that provides care to chronic kidney disease (CKD) patients. In this study, we report the global results of CKD patient outcomes and a comparison between those treated at the NRHP-UY Units, with those patients who were initially included in the program but did not adhere to follow up.

METHODS

A cohort of not-on dialysis CKD patients included prospectively in the NRHP-UY between October 1st 2004 and September 30th 2017 was followed-up until September 30th 2019. Two groups were compared: a) Nephrocare Group: Patients who had at least one clinic visit during the first year on NRHP-UY (n = 11174) and b) Non-adherent Group: Patients who were informed and accepted to be included but had no subsequent data registered after admission (n = 3485). The study was approved by the Ethics Committee and all patients signed an informed consent. Outcomes were studied with Logistic and Cox´s regression analysis, Fine and Gray competitive risk and propensity-score matching tests.

RESULTS

14659 patients were analyzed, median age 70 (60-77) years, 56.9% male. The Nephrocare Group showed improved achievement of therapeutic goals, ESKD was more frequent (HR 2.081, CI 95%1.722-2.514) as planned kidney replacement therapy (KRT) start (OR 2.494, CI95% 1.591-3.910), but mortality and the combined event (death and ESKD) were less frequent (HR 0.671, CI95% 0.628-0.717 and 0.777, CI95% 0.731-0.827) (p = 0.000) compared to the Non-adherent group. Results were similar in the propensity-matched group: ESKD (HR 2.041, CI95% 1.643-2.534); planned kidney replacement therapy (KRT) start (OR 2.191, CI95% 1.322-3.631) death (HR 0.692, CI95% 0.637-0.753); combined event (HR 0.801, CI95% 0.742-0.865) (p = 0.000).

CONCLUSION

Multidisciplinary care within the NRHP-UY is associated with timely initiation of KRT and lower mortality in single outcomes, combined analysis, and propensity-matched analysis.

Evaluating the safety and efficacy of daprodustat for anemia of chronic kidney disease: a meta-analysis of randomized clinical trials

PURPOSE

Anemia of chronic kidney disease (CKD) has traditionally been treated with recombinant human erythropoietin (rhEPO). Recently, daprodustat, a hypoxia-inducible factor prolyl-hydroxylase inhibitor, has also been shown to increase hematocrit. It remains unclear whether daprodustat or rhEPO should be the treatment of choice for anemia of CKD. We aimed to assess the efficacy and cardiovascular safety of daprodustat versus rhEPO in CKD patients.

METHODS

Online databases were queried in April 2022 for articles comparing the efficacy and safety of daprodustat in DD-CKD and NDD-CKD subgroups. Results from trials were pooled using a random-effects model.

RESULTS

Data on 8245 CKD patients from eight clinical trials were included. Our results show that in comparison to rhEPO, daprodustat maintained the same efficacy in increasing hemoglobin levels in both the DD-CKD (MD: 0.10; 95% CI [- 0.13,0.34]; p = 0.50) and NDD-CKD (MD: - 0.01; 95% CI [- 0.38,0.35]; p = 0.95) subgroups. Daprodustat significantly lowered hepcidin levels and significantly increased TIBC in both subgroups. Additionally, daprodustat significantly reduced the incidence of major adverse cardiovascular events (MACE) (RR: 0.89; 95% CI: 0.89-0.98; p = 0.02) and its myocardial infarction (MI) component (RR: 0.74; 95% CI: 0.59-0.92; p = 0.006) in the DD-CKD subgroup.

CONCLUSION

Daprodustat has similar efficacy compared to rhEPO for the treatment of anemia of CKD. On treatment, the reduced experience of MACE was reported in DD-CKD patients as compared to rhEPO. Furthermore, effects on iron metabolism varied by parameter, with daprodustat being superior to rhEPO in some cases and inferior in others.

Iron deficiency screening is a key issue in chronic inflammatory diseases: A call to action

Iron deficiency is frequent in patients with chronic inflammatory conditions (e.g., chronic heart failure, chronic kidney disease, cancers, and bowel inflammatory diseases). Indeed, high concentrations of inflammatory cytokines increase hepcidin concentrations that lead to the sequestration of iron in cells of the reticuloendothelial system (functional iron deficiency). Iron parameters are often assessed only in the context of anemia, but iron deficiency, even without anemia, is present in about half of patients with inflammatory conditions. Iron deficiency worsens underlying chronic diseases and is an independent factor of morbidity and mortality. In daily practice, the most effective biomarkers of iron status are serum ferritin, which reflects iron storage, and transferrin saturation, which reflects the transport of iron. Serum ferritin is increased in an inflammatory context, and there is still no consensus on the threshold to be used in chronic inflammatory conditions. Nevertheless, recent recommendations of international guidelines agreed to define iron deficiency by serum ferritin &lt;100 µg/L and/or transferrin saturation &lt;20%. Iron parameters remain, however, insufficiently assessed in patients with chronic inflammatory conditions. Indeed, clinical symptoms of iron deficiency, such as fatigue, are not specific and often confused with those of the primary disease. Iron repletion, preferably by the intravenous route to bypass tissue sequestration, improves clinical signs and quality of life. Because of the negative impact of iron deficiency on chronic inflammatory diseases and the efficacy of intravenous iron repletion, screening of iron parameters should be part of the routine examination of all patients with chronic inflammatory diseases.

The Influence of Iron-Deficiency Anaemia (IDA) Therapy on Clinical Outcomes and Healthcare Resource Consumptions in Chronic Kidney Disease Patients Affected by IDA: A Real-Word Evidence Study among the Italian Population

Anaemia is a uraemia-related complication frequently found in non-dialysis-dependent chronic kidney disease (ND-CKD) patients, with iron-deficiency anaemia (IDA) as the main underlying mechanism. Given the suboptimal anaemia management in ND-CKD patients with a co-diagnosis of IDA, this study evaluated the role of IDA therapy on clinical outcomes and healthcare resource consumptions in an Italian clinical setting. A retrospective observational real-world analysis was performed on administrative databases of healthcare entities, covering around 6.9 million health-assisted individuals. From January 2010 to March 2019, ND-CKD patients were included and diagnosed with IDA in the presence of two low-haemoglobin (Hb) measurements. Patients were divided into IDA-treated and untreated, based on the prescription of iron [Anatomical-Therapeutic Chemical (ATC) code B03A] or anti-anaemia preparations (ATC code B03X), and evaluated during a 6-month follow-up from the index date [first low haemoglobin (Hb) detection]. IDA treatment resulted in significantly decreased incidence of all cause-related, cardiovascular-related, and IDA-related hospitalizations (treated vs. untreated: 44.5% vs. 81.8%, 12.3% vs. 25.3%, and 16.2% vs. 26.2%, respectively, p < 0.001). A healthcare direct cost estimation showed that overall mean expenditure per patient reduced by 47% with IDA treatment (5245€ vs. 9918€, p < 0.001), mainly attributable to hospitalizations (3767€ vs. 8486€, p < 0.001). This real-life analysis on Italian ND-CKD-IDA patients indicates that IDA therapy administration provides significant benefits in terms of patients’ clinical outcomes and healthcare cost savings.

Association between haemoglobin concentration and intradialytic hypotension in patients undergoing maintenance haemodialysis: a retrospective cohort study

OBJECTIVES

Haemoglobin concentration is a potentially modifiable factor that may help lower the risk of intradialytic hypotension (IDH), but its association with IDH is not well understood. This study aimed to clarify the relationship between haemoglobin concentration and IDH.

DESIGN

Retrospective cohort study.

SETTING

We evaluated patients undergoing maintenance haemodialysis in December 2017 at Rakuwakai Otowa Kinen Hospital.

PARTICIPANTS

A total of 543 patients were included. We defined exposure according to the following five categories depending on haemoglobin concentrations by 1.0 increments: <9.0, ≥9.0 to <10.0, 10.0 to <11.0, ≥11.0 to <12.0 and ≥12.0 g/dL.

PRIMARY OUTCOME MEASURE

The primary outcome of interest was the development of IDH, defined as any nadir <100 mm Hg if the pre-dialysis systolic blood pressure (SBP) was ≥160 mm Hg or any nadir <90 mm Hg if the pre-dialysis SBP was <160 mm Hg (IDH_nadir).

RESULTS

Overall, IDH_nadir occurred in 14.3% (465/3250) of the sessions. With a haemoglobin concentration of ≥10.0 to <11.0 g/dL set as reference, the adjusted ORs for IDH_nadir were 0.82 (95% CI, 0.32 to 2.15), 1.16 (95% CI, 0.56 to 2.39), 1.26 (95% CI, 0.68 to 2.36) and 3.01 (95% CI, 1.50 to 6.07) for haemoglobin concentrations of <9.0, ≥9.0 to <10.0, ≥11.0 to <12.0 and ≥12.0 g/dL, respectively. In the cubic spline analysis, a high haemoglobin concentration was associated with the development of IDH_nadir.

CONCLUSION

High haemoglobin concentration is associated with IDH, and thus, the upper limit of haemoglobin concentration should be closely monitored in patients with IDH.

Endocrine manifestations of chronic kidney disease and their evolving management: A systematic review

BACKGROUND

Chronic Kidney Disease (CKD) shows a wide range of renal abnormalities including the excretory, metabolic, endocrine, and homeostatic function of the kidney. The prognostic impact of the 'endocrine manifestations' which are often overlooked by clinicians cannot be overstated.

METHODS AND OBJECTIVES

A systematic review was attempted to provide a comprehensive overview of all endocrine abnormalities of CKD and their evolving principles of management, searching databases of PubMed, Embase, and Scopus and covering the literature between 2002 and 2022.

RESULTS

The endocrine derangements in CKD can be attributed to a myriad of pathologic processes, in particular decreased clearance, impaired endogenous hormone production, uremia-induced cellular dysfunction, and activation of systemic inflammatory pathways. The major disorders include anemia, hyperprolactinemia, insulin resistance, reproductive hormone deficiency, thyroid hormone deficiency, and serum FGF (Fibroblast Growth Factor) alteration. Long-term effects of CKD also include malnutrition and increased cardiovascular risk. The recent times have unveiled their detailed pathogenesis and have seen an evolution in the principles of management which necessitates a revision of current guidelines.

CONCLUSION

Increased advertence regarding the pathology, impact, and management of these endocrine derangements can help in reducing morbidity as well as mortality in the CKD patients by allowing prompt individualized treatment. Moreover, with timely and appropriate intervention, a long-term reduction in complications, as well as an enhanced quality of life, can be achieved in patients with CKD.

Differential Pharmacokinetics of Liver Tropism for Iron Sucrose, Ferric Carboxymaltose, and Iron Isomaltoside: A Clue to Their Safety for Dialysis Patients

Anemia is a major complication of end-stage kidney disease (ESKD). Erythropoiesis-stimulating agents and intravenous (IV) iron are the current backbone of anemia treatment in ESKD. Iron overload induced by IV iron is a potential clinical problem in dialysis patients. We compared the pharmacokinetics of liver accumulation of iron sucrose, currently used worldwide, with two third-generation IV irons (ferric carboxymaltose and iron isomaltoside). We hypothesized that better pharmacokinetics of newer irons could improve the safety of anemia management in ESKD. Liver iron concentration (LIC) was analyzed in 54 dialysis patients by magnetic resonance imaging under different modalities of iron therapy. LIC increased significantly in patients treated with 1.2 g or 2.4 g IV iron sucrose (p < 0.001, Wilcoxon test), whereas no significant increase was observed in patients treated with ferric carboxymaltose or iron isomaltoside (p > 0.05, Wilcoxon-test). Absolute differences in LIC reached 25 μmol/g in the 1.2 g iron sucrose group compared with only 5 μmol/g in the 1 g ferric carboxymaltose and 1 g iron isomaltoside groups (p < 0.0001, Kruskal−Wallis test). These results suggest the beneficial consequences of using ferric carboxymaltose or iron isomaltoside on liver structure in ESKD due to their pharmacokinetic ability to minimize iron overload.

High hemoglobin fluctuation was a protective factor for cardiovascular-related death in peritoneal dialysis (PD) patients: A retrospective analysis of 232 patients with PD

Objectives

This study aimed to investigate the effect of hemoglobin (Hb) fluctuation after dialysis on the prognosis of cardiovascular‐related and all‐cause deaths in peritoneal dialysis (PD).

Methods

According to the Hb fluctuation, patients were divided into low fluctuation group, moderate fluctuation group, and high fluctuation group, and then, the effects of Hb fluctuation after dialysis on the prognosis of cardiovascular‐related and all‐cause death in PD were analyzed by regression analysis.

Results

A total of 232 patients were selected in this study. Compared with the low Hb fluctuation group, the moderate and high fluctuation groups had lower body mass index (BMI), estimated glomerular filtration rate (eGFR), and baseline Hb, and the moderate fluctuation group had less erythropoietin (EPO) and dialysis dose. Compared with survivors, patients with cardiovascular‐related and all‐cause deaths had lower mean Hb and Hb fluctuation (all p < 0.05). Cox regression analysis showed that before and after adjusting for confounding factors, Hb fluctuation was still independently correlated with cardiovascular prognosis, and higher Hb fluctuation was still a protective factor for cardiovascular‐related death in the Hb‐substandard group, but there was no significant correlation between Hb fluctuation and all‐cause death. Multivariate linear regression analysis revealed that Hb fluctuation was positively correlated with Kt/V and EPO dosage, but negatively correlated with the baseline Hb.

Conclusion

High Hb fluctuation was a protective factor for cardiovascular‐related death in PD with substandard Hb. Compared with Hb fluctuation, correction of anemia timely and making Hb reaches the standard level had a greater impact on reducing cardiovascular‐related death in PD.

Epidemiology and outcomes in patients with anemia of CKD not on dialysis from a large US healthcare system database: a retrospective observational study

Background

Optimal management of anemia of chronic kidney disease (CKD) remains controversial. This retrospective study aimed to describe the epidemiology and selected clinical outcomes of anemia in patients with CKD in the US.

Methods

Data were extracted from Henry Ford Health System databases. Adults with stages 3a–5 CKD not on dialysis (estimated glomerular filtration rate < 60 mL/min/1.73m²) between January 1, 2013 and December 31, 2017 were identified. Patients on renal replacement therapy or with active cancer or bleeding were excluded. Patients were followed for ≥12 months until December 31, 2018. Outcomes included incidence rates per 100 person-years (PY) of anemia (hemoglobin < 10 g/dL), renal and major adverse cardiovascular events, and of bleeding and hospitalization outcomes. Adjusted Cox proportional hazards models identified factors associated with outcomes after 1 and 5 years.

Results

Among the study cohort (N = 50,701), prevalence of anemia at baseline was 23.0%. Treatments used by these patients included erythropoiesis-stimulating agents (4.1%), iron replacement (24.2%), and red blood cell transfusions (11.0%). Anemia incidence rates per 100 PY in patients without baseline anemia were 7.4 and 9.7 after 1 and 5 years, respectively. Baseline anemia was associated with increased risk of renal and major cardiovascular events, hospitalizations (all-cause and for bleeding), and transfusion requirements. Increasing CKD stage was associated with increased risk of incident anemia, renal and major adverse cardiovascular events, and hospitalizations.

Conclusions

Anemia was a prevalent condition associated with adverse renal, cardiovascular, and bleeding/hospitalization outcomes in US patients with CKD. Anemia treatment was infrequent.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02778-8.

Safety and Effectiveness of Roxadustat in Dialysis-Dependent Patients With Renal Anemia: A Hospital-Based Cohort Study

Background

Randomized controlled trials (RCTs) have shown the efficacy and safety of Roxadustat and conclude that it has the potential to change the treatment for anemia associated with chronic kidney disease. However, the experience of its use from clinical perspectives post-approval is lacking.

Aim

Using a clinical practice context, this study aims to compare Roxadustat's effectiveness and tolerability with Erythropoietin (EPO) in patients with renal anemia undergoing dialysis.

Methods

We examined the clinical records of patients with a diagnosis of renal anemia on dialysis who were prescribed Roxadustat or Erythropoietin at the department of nephrology of the First Affiliated Hospital of Gannan Medical University from January 2021 to December 2021. Eligible hemodialysis (HD) or peritoneal dialysis (PD) patients with renal anemia, aged >18 or <75 years, without infection, active bleeding, and malignancy were recruited. These patients received Roxadustat or EPO based on the preferential prescription choice made by the nephrologists of the department. We retrospectively attempted to determine the treatment response measured by the change in hemoglobin rate, from baseline up to six months. We also explored the impact of various factors on the treatment response and reported adverse events.

Results

A total of 106 patients have been included in the final analysis, with 53 patients in each group. The mean age of the study group was 49.9 ± 13.6 years with the main Hb level at the baseline of 8.1 g/dL ± 1.23 g/dl. The gain of hemoglobin from the baseline averaged over six months was 2.2 ± 2.11 g/dl in the Roxadustat group compared with 1.1 ± 1.67 g/dL in the EPO group (p=0.01). As compared to EPO,Roxadustat reduced the total cholesterol level by -0.59 ± 1.08 mmol/l versus -0.01 ± 1.28 mmol/l (p=0012) and the low-density lipoprotein (LDL) cholesterol by -0.48 ± 1.07 mmol/l versus -0.47 ± 1.05 (p=0.017) in the first three months. Associated factors with a non-response to treatment were age greater than 65 years (OR=6, 95% CI: 1.23-32.46, p=0.02), hypertension (OR=3.5, 95%CI: 0.89-13.25, p=0.060), and heart failure (OR=4.18, 95%CI:4.18 1.04-20.39, p=0.040). Although the proportion of hospitalization and infection was higher in the EPO group and the incidences of gastrointestinal symptoms (vomiting, nausea) and blood transfusions were higher in the Roxadustat group, there were no statistically significant differences.

Conclusion

Roxadustat improved hemoglobin compared to erythropoietin in patients undergoing dialysis with a safe profile but precautions should be taken for old patients with a cardiovascular medical history.

Association of Abnormal Iron Status with the Occurrence and Prognosis of Peritoneal Dialysis-Related Peritonitis: A Longitudinal Data-Based 10-Year Retrospective Study

This retrospective study investigated the effect of iron status on peritonitis by analyzing longitudinal iron parameters in peritoneal dialysis (PD) patients. Patients who received PD at our center from 1 January 2006 to 31 December 2015 were included and followed up until 31 December 2017. According to the joint quartiles of baseline transferrin saturation and ferritin, iron status was categorized as reference iron status (RIS), absolute iron deficiency (AID), functional iron deficiency (FID), and high iron status (HIS). Generalized estimating equations and Cox regression models with time-dependent covariates were used. A total of 1258 PD patients were included; 752 (59.8%) were male, with a mean (±standard deviation) age of 47.4 (±14.9) years. During a median follow-up period of 35.5 (interquartile range, 18.4–60.0) months, 450 (34.3%) patients had 650 episodes of peritonitis. By analyzing longitudinal data, patients with AID were independently positively associated with the occurrence (adjusted odds ratio (AOR) = 1.45) and treatment failure of peritonitis (adjusted hazard ratio (AHR) = 1.85). Patients with HIS were positively associated with the treatment failure of peritonitis (AHR = 2.70). Longitudinal AID and HIS were associated with the episodes and poor prognosis of peritonitis. Active clinical monitoring and correction of iron imbalance in patients with PD are needed.

Roxadustat Versus Epoetin Alfa for Treating Anemia in Patients with Chronic Kidney Disease on Dialysis: Results from the Randomized Phase 3 ROCKIES Study

Background

Concerns regarding cardiovascular safety with current treatments for anemia in patients with dialysis-dependent (DD)-CKD have encouraged the development of alternatives. Roxadustat, an oral hypoxia-inducible factor prolyl hydroxylase inhibitor, stimulates erythropoiesis by increasing endogenous erythropoietin and iron availability.

Methods

In this open-label phase 3 study, patients with DD-CKD and anemia were randomized 1:1 to oral roxadustat three times weekly or parenteral epoetin alfa per local clinic practice. Initial roxadustat dose depended on erythropoiesis-stimulating agent dose at screening for patients already on them and was weight-based for those not on them. The primary efficacy end point was mean hemoglobin change from baseline averaged over weeks 28‒52 for roxadustat versus epoetin alfa, regardless of rescue therapy use, tested for noninferiority (margin, −0.75 g/dl). Adverse events (AEs) were assessed.

Results

Among 2133 patients randomized (n=1068 roxadustat, n=1065 epoetin alfa), mean age was 54.0 years, and 89.1% and 10.8% were on hemodialysis and peritoneal dialysis, respectively. Mean (95% confidence interval) hemoglobin change from baseline was 0.77 (0.69 to 0.85) g/dl with roxadustat and 0.68 (0.60 to 0.76) g/dl with epoetin alfa, demonstrating noninferiority (least squares mean difference [95% CI], 0.09 [0.01 to 0.18]; P<0.001). The proportion of patients experiencing ≥1 AE and ≥1 serious AE was 85.0% and 57.6% with roxadustat and 84.5% and 57.5% with epoetin alfa, respectively.

Conclusions

Roxadustat effectively increased hemoglobin in patients with DD-CKD, with an AE profile comparable to epoetin alfa.

Clinical Trial registry name and registration number:

Safety and Efficacy Study of Roxadustat to Treat Anemia in Patients With Chronic Kidney Disease, on Dialysis. ClinicalTrials.gov Identifier: NCT02174731.

Iron Deficiency is Associated With Platelet Count Elevation in Patients With Dialysis-dependent Chronic Kidney Disease

OBJECTIVE

Iron deficiency is common in patients with end-stage renal disease (ESRD). Platelet count changes may reflect iron status, but the relationship between platelet count and iron indices is unclear in patients with ESRD.

METHODS

We conducted a retrospective study in 1,167 patients with ESRD from 2012 to 2017 in West China Hospital. Baseline data were used to analyze the relationship between the platelet count and iron indices. Patients were followed up for 3 years.

RESULTS

Patients with iron deficiency (both absolute and functional) had a higher platelet count than those without iron deficiency (174 ± 61 × 10⁹/L vs. 153 ± 58 × 10⁹/L, P < .001). Receiver operating characteristic analysis showed a weak predictive power of platelet count on absolute iron deficiency (area under curve 0.620; cutoff value > 137 × 10⁹/L, sensitivity 76%, specificity 43%) and functional iron deficiency (area under curve 0.540; cutoff value > 124 × 10⁹/L, sensitivity 77%, specificity 32%). Platelet count was negatively correlated with ferritin (Spearman's rho [ρ] -0.1547, P < .001), transferrin saturation (ρ = -0.1895, P < .001), and serum iron (ρ = -0.1466, P < .001). The abovementioned correlations remained significant in multivariate regression (β -0.7285, 95% confidence interval [CI] -1.0757 to -0.3814; β -.00347, 95% CI -0.0520 to -0.0174; β -0.0097, 95% CI -0.0159 to -0.0035, respectively). In unadjusted and adjusted Cox regression models, neither baseline platelet count nor relative thrombocytosis was associated with 3-year mortality.

CONCLUSION

There was a weak but significant platelet count elevation in patients with ESRD and with iron deficiency.

KEY WORDS

end-stage renal disease; iron deficiency; iron supplement; mortality; platelet count.

Iron Overload in Chronic Kidney Disease: Less Ferritin, More T2*MRI

To date, there is no consensus on the most reliable marker of iron status in patients with chronic kidney disease (CKD). Serum ferritin is used routinely, although it may be a misleading marker for iron overload. The success of T2* MRI in monitoring iron overload in patients with hemoglobinopathies can be beneficial to monitoring patients with CKD.

Efficacy and Safety of Daprodustat Vs rhEPO for Anemia in Patients With Chronic Kidney Disease: A Meta-Analysis and Trial Sequential Analysis

Introduction: Daprodustat, a novel hypoxia-inducible factor prolyl-hydroxylase inhibitor (HIF-PHI), its efficacy and safety remain unclear. Thus, we conducted this meta-analysis aiming at investigating its efficacy and safety on the treatment of patients with chronic kidney disease (CKD)-related anemia.

Methods: We systematically searched for relevant studies in PubMed, Embase, Cochrane Library and Clinical Trial Registries databases from inception until December 2021. We selected randomized controlled trials comparing daprodustat with recombinant human erythropoietin (rhEPO) in anemia patients with CKD with or without dialysis.

Results: Seven studies including 7933 patients met the inclusion criteria. For both nondialysis-dependent (NDD-) CKD and dialysis-dependent (DD-) CKD patients, the pooled results showed that there was no significant difference in the changes in hemoglobin levels between the daprodustat and rhEPO groups (mean difference (MD) = −0.01, 95% confidence interval (CI) = −0.38, 0.35, p = 0.95; MD = 0.15, 95% CI = −0.29, 0.60, p = 0.50; respectively). In addition, a significant increase in transferrin saturation (TSAT), total iron binding capacity (TIBC) and total iron was observed in daprodustat groups compared with rhEPO groups in DD-CKD patients (p < 0.05). As for safety, the overall frequency of adverse events was similar between the daprodustat and rhEPO groups in DD-CKD patients (relative risk (RR) = 0.99, 95%CI = 0.92, 1.06, p = 0.76), and the trial sequential analysis (TSA) confirmed this result. But for NDD-CKD patients, the incidence of adverse events in the daprodustat groups was significantly higher than that of rhEPO groups (RR = 1.04, 95%CI = 1.01,1.07, p = 0.02), while the TSA corrected this result. No trend of increasing incidence of serious adverse events was found in all daprodustat treated patients, but the TSA could not confirm this result.

Conclusion: Although daprodustat was noninferior to rhEPO in correcting anemia in both NDD-CKD and DD-CKD patients, it seemed to have a better effect on optimizing iron metabolism in DD-CKD patients. Daprodustat may be a promising alternative for the treatment of anemia in patients with CKD. However, due to the lack of included studies, future researches are needed to further evaluate the therapeutic effect of daprodustat.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/, identifier CRD42021229636.

Circulating Omentin-1 levels and altered iron balance in chronic haemodialysis patients

Background

Iron deficiency is highly prevalent among patients undergoing chronic haemodialysis (HD) but its correct identification is often problematic as common biomarkers of iron status, such as transferrin saturation (TSAT) and ferritin, can be altered by inflammation or malnutrition.

Methods

In this pilot multicentre study, we aimed at evaluating circulating levels of Omentin-1, a novel fat depot-specific adipokine that is also involved in iron regulation, in a cohort of 85 chronic HD patients with relation to their iron status.

Results

Omentin-1 levels in HD were statistically higher than in healthy controls (P = 0.03) and there was a significant, growing trend in all iron parameters across Omentin-1 tertiles (P < 0.001). Compared with patients with optimal iron status, Omentin-1 levels were lower in subjects categorized according to TSAT ≤20% or serum ferritin ≤200 μg/L (both P < 0.001) and even more reduced in 19 patients (22%) simultaneously displaying low levels of both markers (P < 0.001). In this latter group, Omentin-1 levels increased in parallel to all other iron markers after iron correction by i.v. supplementation. At multivariate regression analyses, ferritin (β = 0.71; P < 0.001) and TSAT (β = 0.32; P = 0.03) remained the sole independent predictors of Omentin-1 levels. This biomarker also showed a remarkable diagnostic capacity at receiver operating characteristic analyses in identifying iron-depleted HD patients according to a criterion of TSAT ≤20% [area under the curve (AUC) 0.827], ferritin ≤200 μg/L (AUC 0.863) or low levels of both parameters (AUC 0.907).

Conclusions

Findings obtained indicate that Omentin-1 is somewhat involved in iron balance regulation and might be a candidate biomarker for diagnosing and managing altered iron conditions in HD patients.

Post-mortem liver and bone marrow iron quantification in haemodialysis patients: A prospective cohort study

BACKGROUND

Magnetic resonance liver scans indicate that iron overload is common in haemodialysis (HD) patients. However, histological evidence is scarce.

METHODS

Liver biopsy and bone marrow aspirate were obtained in the first 24h post mortem from 21 adult HD patients. Biochemical liver iron content (LIC) was quantified by electrothermal atomization atomic absorption spectrophotometry. Tissue iron deposition was graded in the liver and bone marrow using Scheuer and Gale's criteria, respectively.

FINDINGS

Median LIC was 42.5 (22.9-69.7) μmol/g and the majority (n=11; 57%) had mild to moderate liver iron overload (LIC >36 μmol/g). Scheuer grade was 2 (1-3) and 13 (62%) of liver biopsies had increased (> 1) iron deposition. In the bone marrow, median Gale's grade was 3 (3-4) and 9 (45%) patients had increased (>3) iron content. Contrary to old autopsy studies, done in the pre-erythropoiesis-stimulating agents (ESAs) era, both liver and bone marrow were iron replete and showed a positive correlation (r=0.71, p<0.001). Ferritin proved to have a good diagnostic accuracy for liver iron overload (0.87 95% CI 0.71-1.00) with an optimal cut-off value of 422 ng/ml. Haemoglobin was negatively associated with both LIC (r= -0.46, p=0.04) and iron content in the bone marrow (p=0.04). Patients with increased LIC had higher resistance to ESAs (p=0.02), yet no association with previous IV iron therapy.

INTERPRETATION

In the majority of HD patients there was iron accumulation in both the liver and bone marrow that associated with anaemia severity and resistance to ESAs, suggesting a blocking mechanism of iron's utilization.

FUNDING

None.

Anemia in Chronic Kidney Disease Patients: An Update

Chronic kidney disease (CKD) is one of the most common disabling diseases globally. The main etiopathology of CKD is attributed to progressive renal fibrosis secondary to recurrent renal insults. Anemia is a known complication in CKD patients, associated with higher hospitalization rates and increased mortality risk. CKD-associated anemia (CKD-AA) is either due to true iron deficiency and/or functional iron deficiency anemia. There is new emerging evidence about the effects of erythropoiesis stimulating agents in the treatment of CKD-AA and their role in reversing and preventing kidney fibrosis in the early stages of CKD. This effect potentially provides new scopes in the prevention and treatment of CKD-AA and in decreasing the progression of CKD and the associated long-term complications. Epidemiology, pathophysiology, and treatments of CKD-AA will be discussed.

Towards a Common Definition for the Diagnosis of Iron Deficiency in Chronic Inflammatory Diseases

Iron deficiency (ID) in patients with chronic inflammatory diseases is frequent. However, under-diagnosis is also frequent due to the heterogeneity between guidelines from different medical societies. We applied a common definition for the diagnosis of ID to a large panel of patients with cancer, heart failure (HF), inflammatory bowel disease (IBD), and chronic kidney disease (CKD), where ID was defined as serum ferritin concentration <100 μg/L and/or a transferrin saturation (TSAT) index <20%. Prevalence estimates using this common definition were compared with that obtained with officially accepted definitions (ESMO 2018, ESC 2016, ECCO 2015, and ERBP 2013). For that purpose, we used data collected during the French CARENFER studies, which included 1232, 1733, 1090, and 1245 patients with cancer, HF, IBD, and CKD, respectively. When applying the common definition, ID prevalence increased to 58.1% (vs. 57.9%), 62.8% (49.6%), and 61.2% (23.7%) in cancer, HF, and IBD patients, respectively. Both prevalence estimates were similar (47.1%) in CKD patients. Based on our results, we recommend combining both ferritin concentration and TSAT index to define ID in patients with chronic inflammatory diseases. In those patients, adopting this common definition of ID should contribute to a better screening for ID, whatever the condition.

Daprodustat Accelerates High Phosphate-Induced Calcification Through the Activation of HIF-1 Signaling

Aims: Chronic kidney disease (CKD) is frequently associated with other chronic diseases including anemia. Daprodustat (DPD) is a prolyl hydroxylase inhibitor, a member of a family of those new generation drugs that increase erythropoiesis via activation of the hypoxia-inducible factor 1 (HIF-1) pathway. Previous studies showed that HIF-1 activation is ultimately linked to acceleration of vascular calcification. We aimed to investigate the effect of DPD on high phosphate-induced calcification.

Methods and Results: We investigated the effect of DPD on calcification in primary human aortic vascular smooth muscle cells (VSMCs), in mouse aorta rings, and an adenine and high phosphate-induced CKD murine model. DPD stabilized HIF-1α and HIF-2α and activated the HIF-1 pathway in VSMCs. Treatment with DPD increased phosphate-induced calcification in cultured VSMCs and murine aorta rings. Oral administration of DPD to adenine and high phosphate-induced CKD mice corrected anemia but increased aortic calcification as assessed by osteosense staining. The inhibition of the transcriptional activity of HIF-1 by chetomin or silencing of HIF-1α attenuated the effect of DPD on VSMC calcification.

Conclusion: Clinical studies with a long follow-up period are needed to evaluate the possible risk of sustained activation of HIF-1 by DPD in accelerating medial calcification in CKD patients with hyperphosphatemia.

Medication non-adherence and the achievement of therapeutic goals of anemia therapy among hemodialysis patients in Jordan

OBJECTIVES

Anemia is prevalent in hemodialysis (HD) patients. Data about factors associated with medication non-adherence in anemic HD patients is limited. This study examined determinants of medication non-adherence and its association with achievement of therapeutic goals of anemia measures among HD patients.

METHODS

A cross-sectional study was conducted among a representative group of HD patients in Jordan. Medication adherence was assessed using Morisky Green Levine Medication Adherence Scale (MGL). Other utilized instruments were modified Charlson Comorbidity Index (mCCI), general Health-Related Quality of Life (HRQoL) EQ-5D-5 L, and Hospital Anxiety and Depression Scale (HADS). Pharmacy claim data during the years of (2016-2017) were also retrieved from patients' medical records. Logistic regression was conducted to identify factors associated with medication non-adherence and achieving therapeutic goals of anemia therapy.

RESULTS

More than two-thirds of the participants (69.1%) were found non-adherent and the mean score of MGL scale was 2.4 ± 1.4. The non-adherence rate measured using refill data (69.6%) was comparable to that observed using self-reported MGL instrument. Education level of college or over was significantly associated with lower odds of non-adherence (OR = 0.365, p = 0.036), while complaining of a headache was associated with 2.5-fold risk of medication non-adherence (OR = 2.5, p = 0.017). A trend toward better achievement of iron indices therapeutic goals was observed with improved adherence measured using refill data. Multiple factors such as improved knowledge about prescribed medications was significantly associated with achieving anemia therapeutic goals (p < 0.05).

CONCLUSION

The findings suggest poor medication adherence among HD patients with anemia. Future interventions by health-care providers should target modifiable factors to improve medication adherence and, hence, health outcomes among HD patients with anemia.

Choices in hemodialysis therapies: variants, personalized therapy and application of evidence-based medicine

The extent of removal of the uremic toxins in hemodialysis (HD) therapies depends primarily on the dialysis membrane characteristics and the solute transport mechanisms involved. While designation of ‘flux’ of membranes as well toxicity of compounds that need to be targeted for removal remain unresolved issues, the relative role, efficiency and utilization of solute removal principles to optimize HD treatment are better delineated. Through the combination and intensity of diffusive and convective removal forces, levels of concentrations of a broad spectrum of uremic toxins can be lowered significantly and successfully. Extended clinical experience as well as data from several clinical trials attest to the benefits of convection-based HD treatment modalities. However, the mode of delivery of HD can further enhance the effectiveness of therapies. Other than treatment time, frequency and location that offer clinical benefits and increase patient well-being, treatment- and patient-specific criteria may be tailored for the therapy delivered: electrolytic composition, dialysate buffer and concentration and choice of anticoagulating agent are crucial for dialysis tolerance and efficacy. Evidence-based medicine (EBM) relies on three tenets, i.e. clinical expertise (i.e. doctor), patient-centered values (i.e. patient) and relevant scientific evidence (i.e. science), that have deviated from their initial aim and summarized to scientific evidence, leading to tyranny of randomized controlled trials. One must recognize that practice patterns as shown by Dialysis Outcomes and Practice Patterns Study and personalization of HD care are the main driving force for improving outcomes. Based on a combination of the three pillars of EBM, and particularly on bedside patient–clinician interaction, we summarize what we have learned over the last 6 decades in terms of best practices to improve outcomes in HD patients. Management of initiation of dialysis, vascular access, preservation of kidney function, selection of biocompatible dialysers and use of dialysis fluids of high microbiological purity to restrict inflammation are just some of the approaches where clinical experience is vital in the absence of definitive scientific evidence. Further, HD adequacy needs to be considered as a broad and multitarget approach covering not just the dose of dialysis provided, but meeting individual patient needs (e.g. fluid volume, acid–base, blood pressure, bone disease metabolism control) through regular assessment—and adjustment—of a series of indicators of treatment efficiency. Finally, in whichever way new technologies (i.e. artificial intelligence, connected health) are embraced in the future to improve the delivery of dialysis, the human dimension of the patient–doctor interaction is irreplaceable. Kidney medicine should remain ‘an art’ and will never be just ‘a science’.

Hypoxia-inducible factor-prolyl hydroxylase inhibitors for renal anemia in chronic kidney disease: Advantages and disadvantages

Anemia is a common feature and complication of chronic kidney disease (CKD). Erythropoiesis-stimulating agents (ESAs) and recombinant human erythropoietin have been used widely in renal anemia treatment. Recently, hypoxia-inducible factor-prolyl hydroxylase domain inhibitors (HIF-PHIs) that may improve the treatment of renal anemia patients were launched. Previous studies indicated that HIF-PHIs may decrease hepcidin levels and modulate iron metabolism, thereby increasing total iron-binding capacity and reducing the need for iron supplementation. Furthermore, HIF-PHIs can reduce inflammation and oxidative stress in CKD. Recombinant erythropoietin has become a routine treatment for patients with CKD and end-stage renal disease with relatively few adverse effects. However, higher doses of recombinant erythropoietin have been demonstrated to be an independent predictor of mortality in patients under hemodialysis. Phase III clinical trials of HIF-PHIs in patients with anemia and dialysis-dependent CKD have shown their efficacy and safety in both non-dialysis and dialysis CKD patients. However, HIFα binds to specific hypoxia-response elements in the vascular endothelial growth factor or retinoic acid-related orphan receptor gamma t (RORγt) promoter, which may be involved in the progression of cancer, psoriasis, and rheumatoid arthritis. In this paper, we have summarized the mechanism, clinical application, and clinical trials of HIF-PHIs in the treatment of renal anemia and aimed to provide an overview of the new drugs in clinical practice, as well as reconsider the advantages and disadvantages of HIF-PHIs and ESAs. Presently, there are not enough clinical studies examining the effects of long-term administration of HIF-PHIs. Therefore, further studies will be needed.

INFERR-Iron infusion in haemodialysis study: INtravenous iron polymaltose for First Nations Australian patients with high FERRitin levels on haemodialysis-a protocol for a prospective open-label blinded endpoint randomised controlled trial

BACKGROUND

The effectiveness of erythropoiesis-stimulating agents, which are the main stay of managing anaemia of chronic kidney disease (CKD), is largely dependent on adequate body iron stores. The iron stores are determined by the levels of serum ferritin concentration and transferrin saturation. These two surrogate markers of iron stores are used to guide iron replacement therapy. Most Aboriginal and/or Torres Islander Australians of the Northern Territory (herein respectfully referred to as First Nations Australians) with end-stage kidney disease have ferritin levels higher than current guideline recommendations for iron therapy. There is no clear evidence to guide safe and effective treatment with iron in these patients. We aim to assess the impact of intravenous iron treatment on all-cause death and hospitalisation with a principal diagnosis of all-cause infection in First Nations patients on haemodialysis with anaemia, high ferritin levels and low transferrin saturation METHODS: In a prospective open-label blinded endpoint randomised controlled trial, a total of 576 participants on maintenance haemodialysis with high ferritin (> 700 μg/L and ≤ 2000 μg/L) and low transferrin saturation (< 40%) from all the 7 renal units across the Northern Territory of Australia will be randomised 1:1 to receive intravenous iron polymaltose 400 mg once monthly (200 mg during 2 consecutive haemodialysis sessions) (Arm A) or no IV iron treatment (standard treatment) (Arm B). Rescue therapy will be administered when the ferritin levels fall below 700 μg/L or when clinically indicated. The primary outcome will be the differences between the two study arms in the risk of hospitalisation with all-cause infection or death. An economic analysis and several secondary and tertiary outcomes analyses will also be performed.

DISCUSSION

The INFERR clinical trial will address significant uncertainty on the safety and efficacy of iron therapy in First Nations Australians with CKD with hyperferritinaemia and evidence of iron deficiency. This will hopefully lead to the development of evidence-based guidelines. It will also provide the opportunity to explore the causes of hyperferritinaemia in First Nations Australians from the Northern Territory.

TRIAL REGISTRATION

This trial is registered with The Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12620000705987 . Registered 29 June 2020.

Association between hepatic oxygenation on near-infrared spectroscopy and clinical factors in patients undergoing hemodialysis

The hepato-splanchnic circulation directly influences oxygenation of the abdominal organs and plays an important role in compensating for the blood volume reduction that occurs in the central circulation during hemodialysis (HD) with ultrafiltration. However, the hepato-splanchnic circulation and oxygenation cannot be easily evaluated in the clinical setting of HD therapy. We included 185 HD patients and 15 healthy volunteers as the control group in this study. Before HD, hepatic regional oxygen saturation (rSO2), a marker of hepatic oxygenation reflecting the hepato-splanchnic circulation and oxygenation, was monitored using an INVOS 5100c oxygen saturation monitor. Hepatic rSO2 was significantly lower in patients undergoing HD than in healthy controls (56.4 ± 14.9% vs. 76.2 ± 9.6%, p < 0.001). Multivariable regression analysis showed that hepatic rSO2 was independently associated with body mass index (BMI; standardized coefficient: 0.294), hemoglobin (Hb) level (standardized coefficient: 0.294), a history of cardiovascular disease (standardized coefficient: -0.157), mean blood pressure (BP; standardized coefficient: 0.154), and serum albumin concentration (standardized coefficient: 0.150) in Model 1 via a simple linear regression analysis. In Model 2 using the colloid osmotic pressure (COP) in place of serum albumin concentration, the COP (standardized coefficient: 0.134) was also identified as affecting hepatic rSO2. Basal hepatic oxygenation before HD might be affected by BMI, Hb levels, a history of cardiovascular disease, mean BP, serum albumin concentration, and the COP. Further prospective studies are needed to clarify whether changes in these parameters, including during HD, affect the hepato-splanchnic circulation and oxygenation in HD patients.