Mortality risk in hemodialysis patients according to anemia control and erythropoietin dosing

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.

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.

The Impact of CKD Anaemia on Patients: Incidence, Risk Factors, and Clinical Outcomes-A Systematic Literature Review

Anaemia is a common consequence of chronic kidney disease (CKD); however, the risk factors for its development and its impact on outcomes have not been well synthesised. Therefore, we undertook a systematic review to fully characterise the risk factors associated with the presence of anaemia in patients with CKD and a contemporary synthesis of the risks of adverse outcomes in patients with CKD and anaemia. We searched MEDLINE, EMBASE, and the Cochrane Library from 2002 until 2018 for studies reporting the incidence or prevalence of anaemia and associated risk factors and/or associations between haemoglobin (Hb) or anaemia and mortality, major adverse cardiac events (MACE), hospitalisation, or CKD progression in adult patients with CKD. Extracted data were summarised as risk factors related to the incidence or prevalence of anaemia or the risk (hazard ratio (HR)) of outcome by Hb level (<10, 10-12, >12 g/dL) in patients not on dialysis and in those receiving dialysis. 191 studies met the predefined inclusion criteria. The risk factor most associated with the prevalence of anaemia was CKD stage, followed by age and sex. Mean HRs (95% CI) for all-cause mortality in patients with CKD on dialysis with Hb <10, 10-12, and >12 g/dL were 1.56 (1.43-1.71), 1.17 (1.09-1.26), and 0.91 (0.87-0.96), respectively. Similar patterns were observed for nondialysis patients and for the risks of hospitalisation, MACE, and CKD progression. This is the first known systematic review to quantify the risk of adverse clinical outcomes based on Hb level in patients with CKD. Anaemia was consistently associated with greater mortality, hospitalisation, MACE, and CKD progression in patients with CKD, and risk increased with anaemia severity. Effective treatments that not only treat the anaemia but also reduce the risk of adverse clinical outcomes are essential to help reduce the burden of anaemia and its management in CKD.

Targeting erythropoietin protects against proteinuria in type 2 diabetic patients and in zebrafish

Objective

Adult human kidneys produce erythropoietin (EPO), which regulates red blood cell formation; however, whether EPO also functions directly on kidney development and controls diabetic kidney disease remains unknown. Here we analyzed the role of EPO in kidney development and under hyperglycemic conditions in zebrafish and in humans.

Methods

Diabetic patients and respective controls were enrolled in two cohorts. Serum EPO level and urine protein change upon human EPO administration were then analyzed. Transient knockdown and permanent knockout of EPO and EPOR in renal TG(WT1B:EGFP) zebrafish were established using the morpholino technology and CRISPR/Cas9 technology. Zebrafish embryos were phenotypically analyzed using fluorescence microscopy, and functional assays were carried out with the help of TexasRed labeled 70 kDa Dextran. Apoptosis was determined using the TUNEL assay and Annexin V staining, and caspase inhibitor zVADfmk was used for rescue experiments.

Results

In type 2 diabetic patients, serum EPO level decreased with the duration of diabetes, which was linked to reduced kidney function. Human recombinant EPO supplementation ameliorated proteinuria in diabetic nephropathy patients. In zebrafish, loss-of-function studies for EPO and EPOR, showed morphological and functional alterations within the pronephros, adversely affecting pronephric structure, leading to slit diaphragm dysfunction by increasing apoptosis within the pronephros. Induction of hyperglycemia in zebrafish embryos induced pronephros alterations which were further worsened upon silencing of EPO expression.

Conclusions

EPO was identified as a direct renal protective factor, promoting renal embryonic development and protecting kidneys from hyperglycemia induced nephropathy.

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EPO exhibited renal protective and proteinuria ameliorating function in type 2 DM patients and in hyperglycemic zebrafish embryos.

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Enhanced co-expression of EPO and EPOR was identified in both glomeruli and tubuli of DN patients.

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EPO and its receptor directly regulate physiological kidney development via repressing apoptosis.

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.

Optimal hemoglobin level for anemia treatment in a cohort of hemodialysis patients

BACKGROUND

Anemia is a major risk factor that contributes to mortality in patients with chronic kidney disease. There is controversy over the optimal hemoglobin (Hb) target in these patients. This study investigated the association between Hb level and mortality in a cohort of hemodialysis (HD) patients in Korea.

METHODS

This study was a multicenter prospective observational study of maintenance HD patients that was performed for 5 years in western Seoul, Korea. Three hundred and sixty-two participants were enrolled. Laboratory values and mortality were accessed every 6 months. Repeated measures of laboratory values in each interval were averaged to obtain one semiannual mean value. The Hb values were divided into six groups: (1) Hb<9 g/dL; (2) 9 g/dL≤Hb<10 g/dL; (3) 10 g/dL≤Hb<11 g/dL; (4) 11 g/dL≤Hb<12 g/dL; (5) 12 g/dL≤Hb<13 g/dL; and (6) Hb≥13 g/dL. We analyzed the odds ratio for all-cause mortality, based on the Hb group, and adjusted for demographics and various laboratory values. Statistics were performed with SAS, version 9.1 software (SAS Institute Inc., Cary, NC, USA).

RESULTS

Mortality odds ratios relative to the reference group (10-11 g/dL) in the fully adjusted model were 3.61 for<9 g/dL; 3.17 for 9-10 g/dL(⁎); 4.65 for 11-12 g/dL(⁎); 5.50 for 12-13 g/dL(⁎); and 2.05 for≥13 g/dL ((⁎) indicates P<0.05).

CONCLUSION

In this study, a Hb level of 10-11 g/dL was associated with the lowest mortality among the groups with Hb level<13 g/dL. Larger interventional trials are warranted to determine the optimal Hb target for Korean HD patients.