Erythropoiesis-stimulating agent resistance and mortality in hemodialysis and peritoneal dialysis patients

Erythropoiesis-stimulating agent hyporesponsiveness was associated with worse survival of hemodialysis patients independent of the serum ferritin level

INTRODUCTION

Ferritin level and erythropoiesis-stimulating agent (ESA) responsiveness are each associated with hemodialysis patient survival. We assessed interrelationships between these two vs. survival.

METHODS

Patients in the Japan Dialysis Outcomes and Practice Patterns Study Phases 4-6 (2009-2018) were included. All-cause mortality associations were assessed with progressive adjustment to evaluate covariate influence.

RESULTS

During follow-up (median 2.6 years), 773 of 5154 patients died. After covariate adjustment, the mortality hazard ratio (HR) was 0.99 (95% CI: 0.81, 1.20) for low serum ferritin and 1.12 (CI: 0.89, 1.41) for high serum ferritin. By contrast, mortality risk with elevated ESA resistance index (ERI) persisted after covariate adjustment (HR 1.44, CI [1.17-1.78]). The serum ferritin and ERI interaction was not significant; p > 0.96 across all models.

CONCLUSIONS

Japanese hemodialysis patients with high ERI experienced worse survival independent of serum ferritin levels, highlighting the importance of identifying and mitigating ESA hyporesponsiveness among dialysis patients.

Peritoneal dialysis versus haemodialysis for people commencing dialysis

BACKGROUND

Peritoneal dialysis (PD) and haemodialysis (HD) are two possible modalities for people with kidney failure commencing dialysis. Only a few randomised controlled trials (RCTs) have evaluated PD versus HD. The benefits and harms of the two modalities remain uncertain. This review includes both RCTs and non-randomised studies of interventions (NRSIs).

OBJECTIVES

To evaluate the benefits and harms of PD, compared to HD, in people with kidney failure initiating dialysis.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies from 2000 to June 2024 using search terms relevant to this review. Studies in the Register were identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov. MEDLINE and EMBASE were searched for NRSIs from 2000 until 28 March 2023.

SELECTION CRITERIA

RCTs and NRSIs evaluating PD compared to HD in people initiating dialysis were eligible.

DATA COLLECTION AND ANALYSIS

Two investigators independently assessed if the studies were eligible and then extracted data. Risk of bias was assessed using standard Cochrane methods, and relevant outcomes were extracted for each report. The primary outcome was residual kidney function (RKF). Secondary outcomes included all-cause, cardiovascular and infection-related death, infection, cardiovascular disease, hospitalisation, technique survival, life participation and fatigue.

MAIN RESULTS

A total of 153 reports of 84 studies (2 RCTs, 82 NRSIs) were included. Studies varied widely in design (small single-centre studies to international registry analyses) and in the included populations (broad inclusion criteria versus restricted to more specific participants). Additionally, treatment delivery (e.g. automated versus continuous ambulatory PD, HD with catheter versus arteriovenous fistula or graft, in-centre versus home HD) and duration of follow-up varied widely. The two included RCTs were deemed to be at high risk of bias in terms of blinding participants and personnel and blinding outcome assessment for outcomes pertaining to quality of life. However, most other criteria were assessed as low risk of bias for both studies. Although the risk of bias (Newcastle-Ottawa Scale) was generally low for most NRSIs, studies were at risk of selection bias and residual confounding due to the constraints of the observational study design. In children, there may be little or no difference between HD and PD on all-cause death (6 studies, 5752 participants: RR 0.81, 95% CI 0.62 to 1.07; I2 = 28%; low certainty) and cardiovascular death (3 studies, 7073 participants: RR 1.23, 95% CI 0.58 to 2.59; I2 = 29%; low certainty), and was unclear for infection-related death (4 studies, 7451 participants: RR 0.98, 95% CI 0.39 to 2.46; I2 = 56%; very low certainty). In adults, compared with HD, PD had an uncertain effect on RKF (mL/min/1.73 m2) at six months (2 studies, 146 participants: MD 0.90, 95% CI 0.23 to 3.60; I2 = 82%; very low certainty), 12 months (3 studies, 606 participants: MD 1.21, 95% CI -0.01 to 2.43; I2 = 81%; very low certainty) and 24 months (3 studies, 334 participants: MD 0.71, 95% CI -0.02 to 1.48; I2 = 72%; very low certainty). PD had uncertain effects on residual urine volume at 12 months (3 studies, 253 participants: MD 344.10 mL/day, 95% CI 168.70 to 519.49; I2 = 69%; very low certainty). PD may reduce the risk of RKF loss (3 studies, 2834 participants: RR 0.55, 95% CI 0.44 to 0.68; I2 = 17%; low certainty). Compared with HD, PD had uncertain effects on all-cause death (42 studies, 700,093 participants: RR 0.87, 95% CI 0.77 to 0.98; I2 = 99%; very low certainty). In an analysis restricted to RCTs, PD may reduce the risk of all-cause death (2 studies, 1120 participants: RR 0.53, 95% CI 0.32 to 0.86; I2 = 0%; moderate certainty). PD had uncertain effects on both cardiovascular (21 studies, 68,492 participants: RR 0.96, 95% CI 0.78 to 1.19; I2 = 92%) and infection-related death (17 studies, 116,333 participants: RR 0.90, 95% CI 0.57 to 1.42; I2 = 98%) (both very low certainty). Compared with HD, PD had uncertain effects on the number of patients experiencing bacteraemia/bloodstream infection (2 studies, 2582 participants: RR 0.34, 95% CI 0.10 to 1.18; I2 = 68%) and the number of patients experiencing infection episodes (3 studies, 277 participants: RR 1.23, 95% CI 0.93 to 1.62; I2 = 20%) (both very low certainty). PD may reduce the number of bacteraemia/bloodstream infection episodes (2 studies, 2637 participants: RR 0.44, 95% CI 0.27 to 0.71; I2 = 24%; low certainty). Compared with HD; It is uncertain whether PD reduces the risk of acute myocardial infarction (4 studies, 110,850 participants: RR 0.90, 95% CI 0.74 to 1.10; I2 = 55%), coronary artery disease (3 studies, 5826 participants: RR 0.95, 95% CI 0.46 to 1.97; I2 = 62%); ischaemic heart disease (2 studies, 58,374 participants: RR 0.86, 95% CI 0.57 to 1.28; I2 = 95%), congestive heart failure (3 studies, 49,511 participants: RR 1.10, 95% CI 0.54 to 2.21; I2 = 89%) and stroke (4 studies, 102,542 participants: RR 0.94, 95% CI 0.90 to 0.99; I2 = 0%) because of low to very low certainty evidence. Compared with HD, PD had uncertain effects on the number of patients experiencing hospitalisation (4 studies, 3282 participants: RR 0.90, 95% CI 0.62 to 1.30; I2 = 97%) and all-cause hospitalisation events (4 studies, 42,582 participants: RR 1.02, 95% CI 0.81 to 1.29; I2 = 91%) (very low certainty). None of the included studies reported specifically on life participation or fatigue. However, two studies evaluated employment. Compared with HD, PD had uncertain effects on employment at one year (2 studies, 593 participants: RR 0.83, 95% CI 0.20 to 3.43; I2 = 97%; very low certainty).

AUTHORS' CONCLUSIONS

The comparative effectiveness of PD and HD on the preservation of RKF, all-cause and cause-specific death risk, the incidence of bacteraemia, other vascular complications (e.g. stroke, cardiovascular events) and patient-reported outcomes (e.g. life participation and fatigue) are uncertain, based on data obtained mostly from NRSIs, as only two RCTs were included.

The Influence of Precursor Depletion and dose Regimens on Resistance to Erythropoiesis-Stimulating Agents: Insights from Simulations with Instantaneous Dose-Adaptation Algorithm

Erythropoiesis-stimulating agents (ESAs) have been a common treatment for anemia associated with chronic kidney disease (CKD), while 10-20 % of patients continue to suffer from persistent anemia despite receiving ESA treatments. Our previous findings suggested that intensive ESA usage can cause resistance by depleting the erythroid precursor cells. Here, we used a mechanism-based pharmacokinetic/pharmacodynamic (PK/PD) model of ESAs and conducted simulations to evaluate the influence of dose regimens and other factors (such as administration route, individual PK/PD parameters, types of ESAs, and disease status) on ESA resistance with instantaneous dose adaptations in healthy populations and anemic patients. The simulated results show that instantaneous dose-adaptation can reduce ESA resistance, but up to 30 % of subjects still ended up developing ESA resistance in healthy populations. The Smax is markedly higher in hypo-responders than in normal-responders, while hypo-responders possess fewer precursors and experience a faster decline compared to normal-responders. There is a ceiling effect of increasing ESA dosage to improve HGB responses and reduce ESA resistance, and the limit is lower in anemic patients compared to healthy populations. Subcutaneous administrations and ESAs with longer half-lives lead to stronger HGB responses and less resistance at equivalent doses. Taken together, this study indicates that precursor depletion contributes to ESA resistance and dose regimens can greatly influence the occurrence of ESA resistance. Furthermore, ESA treatment for patients showing ESA resistance should avoid continuously increasing doses and instead consider stimulating the renewal of precursors.

Erythropoiesis-stimulating agents and cardiovascular mortality: A systematic review and meta-analysis of 17 studies and 372,156 hemodialysis patients

Introduction

Prior studies on the association between erythropoiesis-stimulating agents (ESAs) and cardiovascular mortality in hemodialysis patients have yielded conflicting findings. We aimed to clarify this relationship through a systematic review and meta-analysis of current evidence.

Methods

We comprehensively searched major databases for observational and interventional studies on ESA use and cardiovascular mortality in hemodialysis patients published from 1980 to September 2023. Pooled risk ratios (RR) with 95 % confidence intervals (CI) were calculated using random-effects models. Sources of heterogeneity were explored through subgroup analyses and meta-regression. The study data were analyzed using Stata 15 software.

Findings

Upon conducting the initial search, we extracted 792 articles and, after screening and considering the research criteria, 17 studies with 372,156 participants were included in the meta-analysis. Overall, ESA use was associated with a 27 % increased risk of cardiovascular mortality (RR 1.27, 95 % CI: 1.15-1.40, p < 0.001). This risk varied by geographical location, with RRs of 1.27 (95 % CI: 1.14-1.41; p-value≤0.001) for America, 1.33 (95 % CI: 1.12-1.58; p-value = 0.001) for Asia, and 1.23 (95 % CI: 1.02-1.49; p-value = 0.028) for Europe. Importantly, a gender disparity was revealed, with studies involving a higher proportion of males showing greater risks (RR 1.51, 95 % CI: 1.25-1.83, p < 0.001) than female-predominant studies (RR 1.08, 95 % CI: 0.86-1.36, p < 0.001).

Conclusion

Our meta-analysis indicates ESA use is associated with heightened cardiovascular mortality in hemodialysis patients, especially in males. These findings have implications for optimizing dosing strategies while balancing efficacy and safety. Further research is warranted, particularly randomized controlled trials, to establish definitive ESA dosing guidelines.

Investigating the relationship between erythropoiesis-stimulating agents and mortality in hemodialysis patients: A systematic review and meta-analysis

BACKGROUND

In recent years, various studies have been conducted to investigate the relationship between erythropoiesis-stimulating agents (ESAs) and mortality in hemodialysis patients, who showed contradictory results. Therefore, this study aimed to investigate the relationship between ESAs and mortality in hemodialysis patients.

METHODS

The current study is a systematic review and meta-analysis based on observational and interventional studies published in the Web of Science, Cochrane Library, Science Direct, PubMed, Scopus, and Google Scholar databases between 1980 and the end of 2022. Jadad scale checklist and Newcastle Ottawa scale were used to evaluate the quality of articles. The study data were analyzed using Stata 15 software.

RESULTS

In the initial search, 3933 articles were extracted, and by screening and considering the research criteria, 68 studies were finally included in the meta-analysis. According to the meta-analysis results, the risk ratio (RR) of overall mortality in hemodialysis patients receiving ESAs was equal to 1.19 (95% CI: 1.16-1.23, P ≤ 0.001). The RR of mortality in patients aged 60 years and under was equal to 1.33 (1.15-1.55, P ≤ 0.001), in the age group over 60 years was equal to 1.13 (1.10-1.16, P ≤ 0.001), in randomized clinical trial studies was equal to 1.06 (0.80-1.40, P = 0.701), in cohort studies was equal to 1.20 (1.16-1.25, P ≤ 0.001), in American countries was equal to 1.19 (1.10-1.29, P ≤ 0.001), in Asian countries was equal to 1.15 (1.10-1.19, P ≤ 0.001), and in European countries was equal to 1.18 (1.05-1.34, P = 0.007).

CONCLUSION

The results of the study show that receiving ESAs is associated with a 19% increase in the risk of overall mortality in hemodialysis patients.

Changes in erythropoiesis-stimulating agent responsiveness after transfer to combined therapy with peritoneal dialysis and hemodialysis for patients on peritoneal dialysis: A prospective multicenter study in Japan

INTRODUCTION

Inadequate dialysis and fluid overload are corrected after starting combined therapy with peritoneal dialysis (PD) and hemodialysis (HD). However, the effects on anemia management has not been elucidated.

METHODS

We conducted a prospective, multicenter, observational cohort study of 40 PD patients (age, 60 ± 10 years; male, 88%; median PD duration, 28 months) starting combined therapy and investigated changes in several clinical parameters, including erythropoiesis-stimulating agent (ESA) resistance index (ERI).

RESULTS

ERI decreased significantly during 6 months after switching to combined therapy (from 11.8 [IQR 8.0-20.4] units/week/kg/(g/dL) to 7.8 [IQR 3.9-18.6] units/week/kg/(g/dL), p = 0.047). Body weight, urinary volume, serum creatinine and the dialysate-to-plasma creatinine ratio (D/P Cr) decreased, whereas hemoglobin and serum albumin increased. In subgroup analysis, the changes in ERI were not affected by cause for starting combined therapy, PD holiday and D/P Cr.

CONCLUSION

Although detailed mechanism was unclear, ESA responsiveness improved after switching from PD alone to combined therapy.

Scaling Pharmacodynamics from Rats to Humans to Support Erythropoietin and Romiplostim Combination Therapy to Treat Erythropoietin-Resistant Anemia

Recombinant human erythropoietin (rHuEPO) is one of the most effective drugs for the treatment of anemia in patients with chronic kidney disease. However, EPO-resistance is an important contributor to the increased risk of adverse effects. We previously showed that EPO treatment could induce precursor cell depletion, resulting in EPO-resistance. We further found that the combination of EPO with romiplostim, a thrombopoietin receptor agonist that can stimulate the expansion of hematopoietic stem cells, can treat EPO-resistance. In this study, we performed interspecies pharmacodynamic (PD) scaling of this combination therapy for human dose prediction. The pharmacokinetic parameters of both rHuEPO and romiplostim in humans were obtained from previous studies. The PD parameters obtained in rats were scaled to humans using allometric equations. The relationship between PD parameters of the megakaryocyte lineage from rats, monkeys, and humans was in agreement with those from the literature on allometric scaling. The PD response was translated to humans based on allometric scaling and agreed with the observed data. These parameters were used to simulate hemoglobin and platelet response in humans. RHuEPO 50 IU/kg thrice weekly and romiplostim 1 μg/kg once every 4 weeks from the second week is the recommended combination dosing regimen according to the model prediction. Our work successfully scaled the PD of rHuEPO and romiplostim monotherapy from rats to humans. The predicted dosing regimen of each drug in the combination therapy is less intensive than the approved starting dose of each drug, which supports additional evaluations of the combination therapy in humans.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Serum Hepcidin-25 and All-Cause Mortality in Patients Undergoing Maintenance Hemodialysis

Background

Hepcidin plays an important role in iron homeostasis, inhibits intestinal iron absorption and iron release from hepatocytes and macrophages, while its clinical utility remained unclear. This study aimed to investigate the associations between hepcidin-25 and mortality in MHD patients.

Methods

This was a prospective observational cohort of 161 MHD patients, with 2-year follow-up. We investigated the relationships between the variables in our dataset, including serum hepcidin-25, demographic characteristics as well as other clinical parameters.

Results

The median value of baseline serum hepcidin-25 was 31.0 (12.1, 57.3) ng/mL; therefore, the patients were stratified into two groups (low-level hepcidin-25 group, and high-level hepcidin-25 group). The serum iron, serum ferritin, transferrin saturation (TSAT), and hsCRP were higher, pre-dialysis creatinine and albumin were lower, and the scores of health-related qualities of life were worse in the high-level hepcidin-25 group than in the low-level hepcidin-25 group. Maximal information-based nonparametric exploration analysis suggested that serum hepcidin-25 was associated with ferritin, TSAT, and all-cause mortality. The patients with hepcidin-25<31 ng/mL had better survival outcomes than those with hepcidin-25≥31 ng/mL during the 24-month follow-up (Log rank test, P = 0.0017). For per 10ng/mL increase of serum hepcidin-25, the hazard ratio (HR) for all-cause mortality was 1.225 (95% confidence interval [CI]1.085-1.382, P<0.001), which remained significant after multivariate adjustments.

Conclusion

Serum hepcidin-25 was associated with ferritin and TSAT, and could be an independent predictor for all-cause mortality in MHD patients. Further research with larger sample size and longer-term follow-up is still needed.

Direct healthcare costs of chronic kidney disease management in Italy: What cost-savings can be achieved with higher biosimilar uptake and more appropriate use of erythropoiesis-stimulating agents?

PURPOSE

Erythropoiesis-stimulating agents (ESAs), are used for treating chronic kidney disease (CKD)-related anemia, contributing to CKD costs. The study was aimed at investigating direct healthcare costs of CKD patients treated with ESAs and the potential savings achievable by increasing the use of biosimilars and preventing inappropriate ESA use.

METHODS

A multi-center, cohort study was conducted using claims databases of five large Italian geographic areas. Yearly mean direct healthcare costs per patient were estimated, stratifying by CKD stage. The total yearly cost and potential savings related to ESA use were estimated: (a) considering 25/50/75% of originator ESA substitution with biosimilars; (b) eliminating inappropriate ESA dispensing.

RESULTS

During the study period, the ESA-related yearly mean cost represented 17% of total yearly costs in stage I-III, decreasing to 13% in stage IV-V and 6% in dialysis. Among originator users, assuming a 25% of biosimilar uptake, the annual cost-savings of ESA treatment would represent 10.5% of total ESA costs in CKD stage I-V and 7.7% in dialysis. Among incident ESA users for which hemoglobin levels were available, 9% started inappropriately ESA treatment, increasing to 62.0% during the first year of maintenance therapy. Hypothesizing prevention of the first inappropriate ESA dispensing, the total yearly cost-savings would amount to €35 772, increasing to €167 641 eliminating the inappropriate dispensing during maintenance therapy.

CONCLUSIONS

Higher use of lowest cost ESA, prevention of inappropriate ESA use as well as other strategies aimed at slowing down the progressive renal impairment are essential for minimizing clinical and economic burden of CKD.

Clinical and Economic Outcomes of Erythropoiesis-Stimulating Agent Hyporesponsiveness in the Post-Bundling Era

Rationale & Objective

Since the change in erythropoiesis-stimulating agent (ESA) labeling and bundling of dialysis services in the United States, few studies have addressed the clinical importance of ESA hyporesponsiveness and none have considered health care resource use in this population. We aimed to further explore ESA hyporesponsiveness and its consequences.

Study Design

Retrospective observational cohort study.

Setting & Participants

US Renal Data System Medicare participants receiving dialysis with a minimum 6 months of continuous ESA use from 2012 to 2014.

Predictors

Erythropoietin resistance index (≥2.0 U/kg/wk/g/L) and ESA dose were used to identify ESA hyporesponders and hyporesponsive subgroups: isolated, intermittent, and chronic.

Outcomes

Associations between ESA responsiveness and mortality, cardiovascular hospitalization rates, and health care resource use were evaluated and compared across subgroups.

Analytical Approach

Baseline characteristics were compared using Wilcoxon rank sum tests for continuous variables and χ² tests for categorical variables. Incidence rates of health care resource use were modeled using an unadjusted and adjusted generalized linear model.

Results

Of 834,115 dialysis patients in the CROWNWeb database, 38,891 ESA hyporesponders and 59,412 normoresponders met all inclusion criteria. Compared with normoresponders, hyporesponders were younger women, weighed less, and had longer durations of dialysis (all P < 0.001). Hyporesponders received 3.8-fold higher ESA doses (mean, 94,831 U/mo) and erythropoietin resistance index was almost 5 times higher than in normoresponders. Hyporesponders had lower hemoglobin levels and parathyroid hormone levels > 800 pg/mL, and iron deficiency was present in 26.5% versus 10.9% in normoresponders. One-year mortality was higher among hypo- compared with normoresponders (25.3% vs 22.6%). Hyporesponders also had significantly higher rates of hospitalization for cardiovascular events, emergency department visits, inpatient stays, home health agency visits, skilled nursing facility, and hospice days.

Limitations

Only US Medicare patients were included and different hyporesponder definitions may have influenced the results.

Conclusions

This study explored ESA hyporesponsiveness using new definitions and incorporated clinical and economic outcomes. It established that ESA-hyporesponsive dialysis patients had higher mortality, cardiovascular hospitalization rates, and health care costs as compared with ESA-normoresponsive patients.

Tissue sodium concentrations in chronic kidney disease and dialysis patients by lower leg sodium-23 magnetic resonance imaging

BACKGROUND

Sodium-23 magnetic resonance imaging (23Na MRI) allows direct measurement of tissue sodium concentrations. Current knowledge of skin, muscle and bone sodium concentrations in chronic kidney disease (CKD) and renal replacement therapy patients is limited. In this study we measured the tissue sodium concentrations in CKD, hemodialysis (HD) and peritoneal dialysis (PD) patients with 23Na MRI of the lower leg and explored their correlations with established clinical biomarkers.

METHODS

Ten healthy controls, 12 CKD Stages 3-5, 13 HD and 10 PD patients underwent proton and 23Na MRI of the leg. The skin, soleus and tibia were segmented manually and tissue sodium concentrations were measured. Plasma and serum samples were collected from each subject and analyzed for routine clinical biomarkers. Tissue sodium concentrations were compared between groups and correlations with blood-based biomarkers were explored.

RESULTS

Tissue sodium concentrations in the skin, soleus and tibia were higher in HD and PD patients compared with controls. Serum albumin showed a strong, negative correlation with soleus sodium concentrations in HD patients (r = -0.81, P < 0.01). Estimated glomerular filtration rate showed a negative correlation with tissue sodium concentrations (soleus: r = -0.58, P < 0.01; tibia: r = -0.53, P = 0.01) in merged control-CKD patients. Hemoglobin was negatively correlated with tissue sodium concentrations in CKD (soleus: r = -0.65, P = 0.02; tibia: r = -0.73, P < 0.01) and HD (skin: r = -0.60, P = 0.04; tibia: r = -0.76, P < 0.01).

CONCLUSION

Tissue sodium concentrations, measured by 23Na MRI, increase in HD and PD patients and may be associated with adverse metabolic effects in CKD and dialysis.

In search of potential predictors of erythropoiesis-stimulating agents (ESAs) hyporesponsiveness: a population-based study

Background

Evidences show that around 20% of biosimilar or originator erythropoiesis-stimulating agents (ESAs) users are hyporesponsive. Controversial post-marketing data exist on the predictors of ESA hyporesponsiveness. The aim of this study was to identify predictors of ESA hyporesponsiveness in patients with chronic kidney disease (CKD) or cancer in clinical practice.

Methods

During the years 2009–2015, a multi-center, population-based, cohort study was conducted using claims databases of Treviso and Caserta Local Health Units (LHUs). All incident ESA users were characterized at baseline and the differences between the baseline hemoglobin (Hb) value, that is the Hb registered within 30 days prior to the first ESA dispensing (index date, ID) and each outcome Hb value (registered between 30 and 180 days after ID) were calculated and defined as delta Hb (ΔHb). Incident ESA users were defined as hyporesponsive if, during follow-up, they registered at least one ΔHb < 0 g/dL. Including all potential predictors of ESA hyporesponsiveness and stratifying by indication for use, univariate and multivariate binary logistic regression models and Receiver Operating Characteristic (ROC) curves were carried out.

Results

In general, 1080 incident ESA users (CKD: 57.0%; cancer: 43.0%) were identified. In CKD, predictors of ESA hyporesponsiveness were C-reactive protein (OR = 1.2, 95% CI: 1.0–1.5; P-value = 0.060) and high levels of baseline Hb (OR = 1.7, 95% CI: 1.2–2.2; P-value< 0,001), the latter being also predictor of ESA hyporesponsiveness in cancer (OR = 1.7, 95% CI: 1.1–2.4; P-value = 0.007). Both in CKD and in cancer, the type of ESA, biosimilar or originator, was not a predictor of ESA hyporesponsiveness. In CKD, concomitant use of iron preparations (OR = 0.3, 95% CI: 0.2–0.7; P-value = 0.002) and of high dosage of angiotensin-converting enzyme inhibitors/angiotensin II-receptor blockers (OR = 0.5, 95% CI: 0.3–0.9; P-value = 0.022) were protective factors against ESA hyporesponsiveness.

Conclusions

The study confirmed traditional potential predictors of hyporesponsiveness to ESA. The use of biosimilar or originator ESA was not a predictor of hyporesponsiveness in an outpatient setting from two large Italian areas. A better knowledge of the predictors of ESA response would allow a better anemia management to improve patients’ quality of life.

Influence of gender and age on haemodialysis practices: a European multicentre analysis

Background

Women of all ages and elderly patients of both genders comprise an increasing proportion of the haemodialysis population. Worldwide, significant differences in practice patterns and treatment results exist between genders and among younger versus older patients. Although efforts to mitigate sex-based differences have been attempted, significant disparities still exist.

Methods

This retrospective cohort study included all 1247 prevalent haemodialysis patients in DaVita units in Portugal (five dialysis centres, n = 730) and Poland (seven centres, n = 517). Demographic data, dialysis practice patterns, vascular access prevalence and the achievement of a variety of Kidney Disease: Improving Global Outcomes (KDIGO) treatment targets were evaluated in relation to gender and age groups.

Results

Body weight and the prescribed dialysis blood flow rate were lower in women (P < 0.001), whereas treated blood volume per kilogram per session was higher (P < 0.01), resulting in higher single-pool Kt/V in women than in men (P < 0.001). Haemoglobin was significantly higher in men (P = 0.01), but the proportion of patients within target range (10–12 g/dL) was similar. Men more often had an arteriovenous fistula than women (80% versus 73%; P < 0.01) with a similar percentage of central venous catheters. There were no gender-specific differences in terms of dialysis adequacy, anaemia parameters or mineral and bone disorder parameters, or in the attainment of KDIGO targets between women and men >80 years of age.

Conclusions

This large, multicentre real-world analysis indicates that haemodialysis practices and treatment targets are similar for women and men, including the most elderly, in DaVita haemodialysis clinics in Europe.

Forecast post-dialysis blood pressure in hemodialysis patients with intradialytic hypertension

Background: Intradialytic hypertension (IDH) is emerging as an important issue in maintenance hemodialysis (MHD) patients. This study aimed to discuss potential factors related to IDH and build forecasting models for post-dialysis blood pressure (BP) in MHD patients with IDH. Methods: A total of 266 MHD patients were enrolled, included 133 (50%) patients with IDH and 133 patients without IDH. The BP and pulse were determined and recorded over six consecutive dialysis treatments. Forecasting models were established by simple and multiple linear regressions. The Pearson correlation coefficient was used to estimate the association between the values of SBP at pre-HD, intra-HD and post-HD. Results: Lower levels of hemoglobin, albumin, folic acid and magnesium, higher levels of high sensitivity C-reactive protein, ferritin, and erythropoiesis-stimulating agents resistance index (ERI) were detected in the IDH patients. The IDH patients also had lower dry weight, ejection fraction of left ventricular (LVEF), higher interdialytic weight gain (IDWG, % post-HD body weight), and ventricular cardiothoracic ratio (CTR) than non-IDH patients. A linear relationship was revealed between intradialytic SBP in IDH patients, indicating that the pre-HD and intra-HD SBP were correlated with post-HD SBP. Furthermore, simple and multiple linear regression models were built to forecast the values of post-HD SBP in IDH patients. Conclusions: The chronic inflammation, poor IDWG control, LV diastolic dysfunction, as well as low serum folic acid and magnesium might be associated with increasing prevalence of IDH in MHD patients. Forecasting models for post-HD SBP could help to control hypertension during HD treatments.

Sex and gender differences in chronic kidney disease: progression to end-stage renal disease and haemodialysis

Sex and gender differences are of fundamental importance in most diseases, including chronic kidney disease (CKD). Men and women with CKD differ with regard to the underlying pathophysiology of the disease and its complications, present different symptoms and signs, respond differently to therapy and tolerate/cope with the disease differently. Yet an approach using gender in the prevention and treatment of CKD, implementation of clinical practice guidelines and in research has been largely neglected. The present review highlights some sex- and gender-specific evidence in the field of CKD, starting with a critical appraisal of the lack of inclusion of women in randomized clinical trials in nephrology, and thereafter revisits sex/gender differences in kidney pathophysiology, kidney disease progression, outcomes and management of haemodialysis care. In each case we critically consider whether apparent discrepancies are likely to be explained by biological or psycho-socioeconomic factors. In some cases (a few), these findings have resulted in the discovery of disease pathways and/or therapeutic opportunities for improvement. In most cases, they have been reported as merely anecdotal findings. The aim of the present review is to expose some of the stimulating hypotheses arising from these observations as a preamble for stricter approaches using gender for the prevention and treatment of CKD and its complications.

The Safety of Erythropoiesis-Stimulating Agents for the Treatment of Anemia Resulting from Chronic Kidney Disease

Chronic kidney disease (CKD) anemia treatment was revolutionized in the late 1980s with the introduction of recombinant human erythropoietin. This and related erythropoiesis-stimulating agents (ESAs) greatly benefited patients by decreasing debilitating symptoms, improving their quality of life, and freeing them from dependence on blood transfusions with their associated complications such as infections, sensitization impeding transplantation, and secondary iron overload. However, even in the initial studies, untoward effects were noted in patients receiving ESAs, including worsening hypertension, seizures, and dialysis access clotting. Later, increased mortality, malignancy progression and even stroke were reported in renal patients. This review focuses on the safety issues of ESAs in CKD patients.

Effect of Predialysis Recombinant Human Erythropoietin on Early Survival After Hemodialysis Initiation in Patients With Chronic Kidney Disease: Co-JET Study

Progression of anemia in patients with chronic kidney disease (CKD) is associated with an increased risk of death and hospitalization. It is not sufficiently clear whether treating renal anemia with recombinant human erythropoietin (rHuEPO) has a beneficial effect on early survival after hemodialysis (HD) initiation in patients with CKD. The study was an open-label multicenter retrospective cohort study to evaluate the relationship between rHuEPO treatment and early survival after HD initiation in patients with CKD. Predialysis patients with CKD were divided into two groups: an rHuEPO-treated group (rHuEPO group) and a non-treatment group. The primary endpoint was all-cause mortality in the year after HD initiation. A total of 3261 patients were enrolled (2275 in the rHuEPO group and 986 in the non-treatment group). One-year survival was 95.36% in the rHuEPO group and 90.36% in the non-treatment group. The survival rate was significantly higher in the rHuEPO group (P < 0.0001). The results of multivariate analysis confirmed that predialysis treatment with rHuEPO is a predictor for reduced mortality risk (hazard ratio = 0.61, 95% confidence interval: 0.42-0.87, P = 0.006). Risk for the composite event of death/hospitalization was also lower in the rHuEPO group (hazard ratio = 0.88, 95% confidence interval: 0.78-0.98, P = 0.026). The results of this study suggest that treatment with rHuEPO can decrease early mortality risk after initiation of HD in patients with CKD. A prospective study is needed to further investigate early survival after HD initiation.

Spectrum and Burden of Erythropoiesis-Stimulating Agent Hyporesponsiveness Among Contemporary Hemodialysis Patients

BACKGROUND

Hemodialysis patients with erythropoiesis-stimulating agent (ESA) hyporesponsiveness have been a topic of active research. However, there have been no studies of ESA hyporesponsiveness among US patients following the dramatic change in anemia management that resulted from the 2011 changes in ESA product labeling and bundling of dialysis remuneration.

STUDY DESIGN

Retrospective observational study.

SETTING & PARTICIPANTS

We studied prevalent hemodialysis patients treated at a large dialysis organization in calendar years 2012 to 2013 (N=98,972).

PREDICTOR

ESA hyporesponsiveness, defined as 2 consecutive hemoglobin measurements < 10g/dL (every other week) with contemporaneous ESA dose > 7,700U/treatment. Patients with ESA hyporesponsiveness were identified during the first quarter of 2012 and followed up through 2013 using intention-to-treat principles.

OUTCOMES

Associations between the study exposure (ESA hyporesponsiveness) and mortality, missed hemodialysis treatments, ESA and iron use, and hemoglobin levels were determined using generalized estimating equations adjusting for imbalanced baseline covariates.

RESULTS

At baseline, 12,361 (12.5%) patients were identified as having ESA hyporesponsiveness. The mean hemoglobin level among patients with ESA hyporesponsiveness was ∼1g/dL lower than in patients without ESA hyporesponsiveness at baseline, narrowing over follow-up to 0.4g/dL. Initially, mean ESA use was approximately 3-fold greater for patients with ESA hyporesponsiveness than for those without ESA hyporesponsiveness, decreasing to 2-fold greater at study end; iron use and missed hemodialysis treatment rates were also greater among patients with ESA hyporesponsiveness throughout. ESA hyporesponsiveness was associated with enhanced mortality risk versus non-ESA hyporesponsiveness: adjusted incidence rate ratios were estimated at 2.24 (95% CI, 1.93-2.60) in the second quarter, gradually decreasing to 1.48 (95% CI, 1.18-1.84) by study end.

LIMITATIONS

It is possible that an alternative ESA hyporesponsiveness definition may be optimal. As such, the associations we observed may be conservative estimates of true relationships.

CONCLUSIONS

When using a contemporary definition at one point in time, ESA hyporesponsiveness was potently and persistently associated with greater mortality, greater iron and ESA use, and lower hemoglobin levels compared to non-ESA hyporesponsiveness.

Association of Erythropoietin-Stimulating Agent Responsiveness with Mortality in Hemodialysis and Peritoneal Dialysis Patients

Erythropoiesis-stimulating agent (ESA) responsiveness has been reported to be associated with increased mortality in hemodialysis (HD) patients. ESA requirement to obtain the same hemoglobin (Hb) level is different between HD and peritoneal dialysis (PD) patients. In this study, we investigated the impact of ESA responsiveness on mortality between both HD and PD patients. Prevalent HD and PD patients were selected from the Clinical Research Center registry for end-stage renal disease, a prospective cohort study in Korea. ESA responsiveness was estimated using an erythropoietin resistant index (ERI) (U/kg/week/g/dL). Patients were divided into three groups by tertiles of ERI. ESA responsiveness was also assessed based on a combination of ESA dosage and hemoglobin (Hb) levels. The primary outcome was all-cause mortality. A total of 1,594 HD and 876 PD patients were included. The median ESA dose and ERI were lower in PD patients compared with HD patients (ESA dose: 4000 U/week vs 6000 U/week, respectively. P<0.001, ERI: 7.0 vs 10.4 U/kg/week/g/dl, respectively. P<0.001). The median follow-up period was 40 months. In HD patients, the highest ERI tertile was significantly associated with higher risk for all-cause mortality (HR 1.96, 95% CI, 1.07 to 3.59, P = 0.029). HD patients with high-dose ESA and low Hb levels (ESA hypo-responsiveness) had a significantly higher risk of all-cause mortality (HR 2.24, 95% CI, 1.16 to 4.31, P = 0.016). In PD patients, there was no significant difference in all-cause mortality among the ERI groups (P = 0.247, log-rank test). ESA hypo-responsiveness was not associated with all-cause mortality (HR = 1.75, 95% CI, 0.58 to 5.28, P = 0.319). Our data showed that ESA hypo-responsiveness was associated with an increased risk of all-cause mortality in HD patients. However, in PD patients, ESA hypo-responsiveness was not related to all-cause mortality. These finding suggest the different prognostic value of ESA responsiveness between HD and PD patients.

Characterization of chronic and acute ESA hyporesponse: a retrospective cohort study of hemodialysis patients

Background

Some patients with chronic kidney disease do not respond adequately to erythropoiesis-stimulating agent (ESA) treatment; these patients are referred to as ESA hyporesponders. There is no widely accepted contemporary definition for chronic ESA hyporesponse. The study objective was to propose and validate an operational definition for chronic ESA hyporesponse.

Methods

This was a retrospective cohort study using electronic health care records. Participants were anemic hemodialysis patients treated during February 2012 and were followed for 15 months. Patients’ ESA response (responders) or lack of response (chronic and acute hyporesponders) based on longitudinal patterns of ESA dose and hemoglobin level was assessed. Persistence of hyporesponse, longitudinal iron measures, transfusion rates, and mortality rates were analyzed. Frequency of blood transfusions (monthly) and death rates (quarterly) were calculated. Log normalized serum ferritin concentration was analyzed.

Results

Of 97,677 eligible patients, 6632 had acute hyporesponsiveness (ESA responsiveness restituted in ≤ 4 months) and 3086 had chronic hyporesponsiveness (lack of ESA response for > 4 months). Over months 1–4 among chronic hyporesponders, mean serum ferritin (722–785 ng/mL) and transferrin saturation (TSAT; 26.76 %-27.08 %) were constant, while acute hyporesponsive patients experienced increased ferritin (654-760 ng/mL) and TSAT (25.71–30.88 %) levels. Compared to ESA responders (0.19–0.30 %), chronic hyporesponders were transfused 7-times (1.20–2.17 %) more frequently over follow-up. Quarterly mortality was greatest in chronic ESA hyporesponders (2.98–5.48 %), followed by acute ESA hyporesponders (2.17–3.30 %) and ESA responders (1.43–2.49 %). With consistence over the study, chronic hyporesponders died more frequently than patients in the other study cohorts.

Conclusions

Findings indicate that 4 months of continuous ESA hyporesponsiveness can be used to differentiate acute from chronic hyporesponsiveness. This definition of chronic hyporesponsiveness is supported by outcome data showing higher mortality and transfusion rates in chronic hyporesponders compared to acute hyporesponders.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0138-x) contains supplementary material, which is available to authorized users.