Functional Selectivity in Cytokine Signaling Revealed Through a Pathogenic EPO Mutation.

Cytokines are classically thought to stimulate downstream signaling pathways through monotonic activation of receptors. We describe a severe anemia resulting from a homozygous mutation (R150Q) in the cytokine erythropoietin (EPO). Surprisingly, the EPO R150Q mutant shows only a mild reduction in affinity for its receptor but has altered binding kinetics. The EPO mutant is less effective at stimulating erythroid cell proliferation and differentiation, even at maximally potent concentrations. While the EPO mutant can stimulate effectors such as STAT5 to a similar extent as the wild-type ligand, there is reduced JAK2-mediated phosphorylation of select downstream targets. This impairment in downstream signaling mechanistically arises from altered receptor dimerization dynamics due to extracellular binding changes. These results demonstrate how variation in a single cytokine can lead to biased downstream signaling and can thereby cause human disease. Moreover, we have defined a distinct treatable form of anemia through mutation identification and functional studies.

Erythropoietin signaling in peripheral macrophages is required for systemic ß-amyloid clearance.

Impaired clearance of beta-amyloid (Aß) is a primary cause of sporadic Alzheimer's disease (AD). Aß clearance in the periphery contributes to reducing brain Aß levels and preventing Alzheimer's disease pathogenesis. We show here that erythropoietin (EPO) increases phagocytic activity, levels of Aß-degrading enzymes, and Aß clearance in peripheral macrophages via PPARγ. Erythropoietin is also shown to suppress Aß-induced inflammatory responses. Deletion of EPO receptor in peripheral macrophages leads to increased peripheral and brain Aß levels and exacerbates Alzheimer's-associated brain pathologies and behavioral deficits in AD-model mice. Moreover, erythropoietin signaling is impaired in peripheral macrophages of old AD-model mice. Exogenous erythropoietin normalizes impaired EPO signaling and dysregulated functions of peripheral macrophages in old AD-model mice, promotes systemic Aß clearance, and alleviates disease progression. Erythropoietin treatment may represent a potential therapeutic approach for Alzheimer's disease.

Regulation of Erythropoiesis by the Hypoxia-Inducible Factor Pathway: Effects of Genetic and Pharmacological Perturbations.

Red blood cells transport O2 from the lungs to body tissues. Hypoxia stimulates kidney cells to secrete erythropoietin (EPO), which increases red cell mass. Hypoxia-inducible factors (HIFs) mediate EPO gene transcriptional activation. HIF-α subunits are subject to O2-dependent prolyl hydroxylation and then bound by the von Hippel-Lindau protein (VHL), which triggers their ubiquitination and proteasomal degradation. Mutations in the genes encoding EPO, EPO receptor, HIF-2α, prolyl hydroxylase domain protein 2 (PHD2), or VHL cause familial erythrocytosis. In addition to O2, α-ketoglutarate is a substrate for PHD2, and analogs of α-ketoglutarate inhibit hydroxylase activity. In phase III clinical trials evaluating the treatment of anemia in chronic kidney disease, HIF prolyl hydroxylase inhibitors were as efficacious as darbepoetin alfa in stimulating erythropoiesis. However, safety concerns have arisen that are focused on thromboembolism, which is also a phenotypic manifestation of VHL or HIF-2α mutation, suggesting that these events are on-target effects of HIF prolyl hydroxylase inhibitors.

Dysregulation of stress erythropoiesis and enhanced susceptibility to Salmonella Typhimurium infection in AhR-deficient mice.

BACKGROUND: By acting as an environmental sensor, the ligand-induced transcription factor aryl hydrocarbon receptor (AhR) regulates acute innate and adaptive immune responses against pathogens. Here, we analyzed the function of AhR in a model for chronic systemic infection with attenuated Salmonella Typhimurium (STM). METHODS: WT and AhR-deficient mice were infected with the attenuated STM strain TAS2010 and analyzed for bacterial burden, host defense functions and inflammatory stress erythropoiesis. RESULTS: AhR-deficient mice were highly susceptible to TAS2010 infection compared with WT mice demonstrated by reduced bacterial clearance and increased mortality. STM infection resulted in macrocytic anemia and enhanced splenomegaly along with destruction of the splenic architecture in AhR-deficient mice. In addition, AhR-deficient mice displayed a major expansion of splenic immature red blood cells, indicative of infection-induced stress erythropoiesis. Elevated serum levels of erythropoietin and interleukin-6 upon infection as well as increased numbers of splenic stress erythroid progenitors already in steady state probably drive this effect and might cause the alterations in splenic immune cell compartments, thereby preventing an effective host defense against STM in AhR-deficient mice. CONCLUSIONS: AhR-deficient mice fail to clear chronic TAS2010 infection due to enhanced stress erythropoiesis in the spleen and accompanying destruction of the splenic architecture.

Roxadustat reduces left ventricular mass index compared to rHuEPO in haemodialysis patients in a randomized controlled trial.

BACKGROUND: Left ventricular hypertrophy (LVH) is highly prevalent in haemodialysis (HD) patients and is associated with an increased risk of death. Roxadustat and recombinant human erythropoietin (rHuEPO, abbreviated as EPO) are the main treatment strategies for renal anaemia in HD patients, but it has not been clear whether there is a difference in their effect on LVH. METHODS: In this multi-centre, prospective, randomized trial of 12-month duration, study participants were randomized in a 1:1 ratio to the roxadustat group or the EPO group. The doses of both treatment regimens were adjusted so that the patients had a haemoglobin level of 10.0-12.0 g per dL. The primary study endpoint was the change from baseline to 12 months in the left ventricular mass index (LVMI, g/m2) measured by echocardiography. RESULTS: In total, 114 patients were enrolled. The mean age was 50 years, and the median dialysis duration was 33 months. Sixty-one patients were men, and 24 were diabetic. LVMI decreased from 116.18 ± 27.84 to 110.70 ± 25.74 g/m2 in the roxadustat group. However, it increased from 109.35 ± 23.41 to 114.99 ± 28.46 g/m2 in the EPO group, with a significant difference in the change in LVMI between the two groups [-5.48 (-11.60 to 0.65) vs. 5.65 (0.74 to 10.55), p < 0.05]. Changes in left ventricular mass, end-diastolic volume and 6-min walk test seemed superior in the roxadustat group. There were no significant differences in other cardiac geometry, biochemical parameters and major adverse cardiovascular events between the two groups. CONCLUSIONS: Compared to EPO, roxadustat is more helpful in the regression of LVH in HD patients.

Fine-tuning the N-glycosylation of recombinant human erythropoietin using Chlamydomonas reinhardtii mutants.

Microalgae are considered as attractive expression systems for the production of biologics. As photosynthetic unicellular organisms, they do not require costly and complex media for growing and are able to secrete proteins and perform protein glycosylation. Some biologics have been successfully produced in the green microalgae Chlamydomonas reinhardtii. However, post-translational modifications like glycosylation of these Chlamydomonas-made biologics have poorly been investigated so far. Therefore, in this study, we report on the first structural investigation of glycans linked to human erythropoietin (hEPO) expressed in a wild-type C. reinhardtii strain and mutants impaired in key Golgi glycosyltransferases. The glycoproteomic analysis of recombinant hEPO (rhEPO) expressed in the wild-type strain demonstrated that the three N-glycosylation sites are 100% glycosylated with mature N-glycans containing four to five mannose residues and carrying core xylose, core fucose and O-methyl groups. Moreover, expression in C. reinhardtii insertional mutants defective in xylosyltransferases A and B and fucosyltransferase resulted in drastic decreases of core xylosylation and core fucosylation of glycans N-linked to the rhEPOs, thus demonstrating that this strategy offers perspectives for humanizing the N-glycosylation of the Chlamydomonas-made biologics.

Relationship of Neonatal Seizure Burden Before Treatment and Response to Initial Antiseizure Medication.

OBJECTIVE: To assess among a cohort of neonates with hypoxic-ischemic encephalopathy (HIE) the association of pretreatment maximal hourly seizure burden and total seizure duration with successful response to initial antiseizure medication (ASM). STUDY DESIGN: This was a retrospective review of data collected from infants enrolled in the HEAL Trial (NCT02811263) between January 25, 2017, and October 9, 2019. We evaluated a cohort of neonates born at ≥36 weeks of gestation with moderate-to-severe HIE who underwent continuous electroencephalogram monitoring and had acute symptomatic seizures. Poisson regression analyzed associations between (1) pretreatment maximal hourly seizure burden, (2) pretreatment total seizure duration, (3) time from first seizure to initial ASM, and (4) successful response to initial ASM. RESULTS: Among 39 neonates meeting inclusion criteria, greater pretreatment maximal hourly seizure burden was associated with lower chance of successful response to initial ASM (adjusted relative risk for each 5-minute increase in seizure burden 0.83, 95% CI 0.69-0.99). There was no association between pretreatment total seizure duration and chance of successful response. Shorter time-to-treatment was paradoxically associated with lower chance of successful response to treatment, although this difference was small in magnitude (relative risk 1.007, 95% CI 1.003-1.010). CONCLUSIONS: Maximal seizure burden may be more important than other, more commonly used measures in predicting response to acute seizure treatments.

Effect of long-term treatment with trivalent chromium on erythropoietin production in HepG2 cells.

Trivalent chromium (Cr(III)) is sometimes taken as a long-term supplement, but its effectiveness is unclear. Recently, Cr(III) reportedly modulates peroxisome proliferator-activated receptor gamma (PPARγ) expression. Our previous study reported that increased PPARγ after 24 h Cr(III) treatment promoted erythropoietin (EPO) production in HepG2 cells. In the current study, we analyzed 4-week Cr(III) treatment effects on PPARγ and EPO production in HepG2 cells. Long-term Cr(III) treatment resulted in significantly elevated mRNA expression levels of PPARγ and EPO compared to controls. Additionally, treatment with a PPARγ inhibitor suppressed EPO mRNA expression. Increased EPO mRNA expression due to stimulation with hypoxia or cobalt was unaffected by long-term Cr(III) treatment. Administration of lipopolysaccharide and pyocyanin which causes oxidative stress, promoted EPO production, but this effect was attenuated in cells treated with Cr(III). Long-term Cr(III) treatment increased hypoxia inducible factor (HIF)-1α and 2α mRNA expression and protein levels. Increased PPARγ, induced by long-term Cr(III) treatment, suppressed sirtuin1 (SIRT1) mRNA expression and increased EPO mRNA expression, suggesting that increased PPARγ attenuated the suppressive effect of SIRT1 on HIF. These results suggest that the sustained increase in PPARγ during long-term Cr(III) treatment maintains increased EPO production through a mechanism different from that observed under hypoxia.

Serum erythropoietin level is increased during stimulation for IVF but not in OHSS.

BACKGROUND: Erythropoietin (Epo) is a potent vascular growth factor that induces angiogenesis and antiapoptotic signalling. We investigated whether the development of numerous follicles and corpora lutea during in vitro fertilization (IVF) cycle affects circulating Epo levels and further, if Epo could be used as a novel marker for ovarian hyperstimulation syndrome (OHSS). METHODS: 24 women were included in the uncomplicated IVF group and 35 women in the OHSS group. Repeated blood samples from both groups were analysed for Epo, progesterone, blood haemoglobin, and creatinine. Follicular fluid from the IVF group was analysed for Epo and progesterone. Repeated measure analysis was performed for the variables and circulating Epo levels were compared between the IVF group and early OHSS. Furthermore, related growth factors, vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1 (HIF-1) were analysed from subgroup of women to test for correlation with Epo. RESULTS: During IVF, circulating Epo increased from natural mid-luteal phase to stimulated mid-luteal phase (median 9.5; 95% CI 7.2-13.4 IU/L and 12.5; 10.3-13.4 IU/L; p = 0.003). In cycles resulting in pregnancy, Epo level decreased 14 days after oocyte pick-up (OPU) and remained low thereafter. In cycles not resulting in pregnancy, Epo level increased again 35 days after OPU. Follicle fluid Epo concentration was 1.5 times higher than the serum concentration (median 15.4; 95% CI 10.4-19.2 IU/L vs. 10.2; 8.8-12.7; p = 0.006). There was no difference in circulating Epo concentration between early OHSS and uncomplicated IVF. Circulating Epo did not correlate with VEGF or HIF-1. CONCLUSIONS: Circulating Epo levels fluctuate during IVF cycle. We hypothesise this may suggest Epo's involvement in ovarian physiology and angiogenesis. However, Epo was not a clinical marker for OHSS.

Mechanistic and Clinical Comparison of the Erythropoietic Effects of SGLT2 Inhibitors and Prolyl Hydroxylase Inhibitors in Patients with Chronic Kidney Disease and Renal Anemia.

Renal anemia is treated with erythropoiesis-stimulating agents (ESAs), even though epoetin alfa and darbepoetin increase the risk of cardiovascular death and thromboembolic events, including stroke. Hypoxia-inducible factor prolyl hydroxylase domain (HIF-PHD) inhibitors have been developed as an alternative to ESAs, producing comparable increases in hemoglobin. However, in advanced chronic kidney disease, HIF-PHD inhibitors can increase the risk of cardiovascular death, heart failure, and thrombotic events to a greater extent than that with ESAs, indicating that there is a compelling need for safer alternatives. Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of major cardiovascular events, and they increase hemoglobin, an effect that is related to an increase in erythropoietin and an expansion in red blood cell mass. SGLT2 inhibitors increase hemoglobin by ≈0.6-0.7 g/dL, resulting in the alleviation of anemia in many patients. The magnitude of this effect is comparable to that seen with low-to-medium doses of HIF-PHD inhibitors, and it is apparent even in advanced chronic kidney disease. Interestingly, HIF-PHD inhibitors act by interfering with the prolyl hydroxylases that degrade both HIF-1α and HIF-2α, thus enhancing both isoforms. However, HIF-2α is the physiological stimulus to the production of erythropoietin, and upregulation of HIF-1α may be an unnecessary ancillary property of HIF-PHD inhibitors, which may have adverse cardiac and vascular consequences. In contrast, SGLT2 inhibitors act to selectively increase HIF-2α, while downregulating HIF-1α, a distinctive profile that may contribute to their cardiorenal benefits. Intriguingly, for both HIF-PHD and SGLT2 inhibitors, the liver is likely to be an important site of increased erythropoietin production, recapitulating the fetal phenotype. These observations suggest that the use of SGLT2 inhibitors should be seriously evaluated as a therapeutic approach to treat renal anemia, yielding less cardiovascular risk than other therapeutic options.

Proton Pump Inhibitors and Hyporesponsiveness to Erythropoiesis-Stimulating Agents in Hemodialysis Patients: Results from the Japan Dialysis Outcomes and Practice Patterns Study.

INTRODUCTION: Hyporesponsiveness to erythropoiesis stimulating agents (ESAs) is important problem in dialysis patients. While proton pump inhibitors (PPIs) may inhibit iron absorption, few studies have examined associations between PPIs and ESA-resistant anemia in hemodialysis patients. This study examined the associations between PPIs and ESA-resistant anemia in hemodialysis patients. METHODS: The present study was a cross-sectional study using repeated 4-month observations, up to eight observations/patient, from the Japan Dialysis Outcomes and Practice Patterns Study (J-DOPPS). The primary outcome was erythropoietin resistance index (ERI). ESA dose, hemoglobin, proportion of erythropoietin-resistant anemia, transferrin saturation (TSAT), and ferritin were also examined. Linear or risk-difference regression models were used with generalized estimating equations to account for repeated measurements. RESULTS: Of 1,644 patients, 867 patients had PPI prescriptions (52.7%). Patients prescribed PPI had higher ERI, higher ESA dose, and lower TSAT levels. Multivariable analysis for 12,048 four-month observations showed significantly greater ERI in PPI users (adjusted difference 0.95 IU/week/kg/[g/dL] [95% CI: 0.40-1.50]). Significant differences were also found in ESA dose (336 IU/week [95% CI: 70-602]) and the prevalence of erythropoietin-resistant anemia (3.9% [2.0-5.8%]) even after adjusted for TSAT and ferritin. Among possible mediators between the association of PPIs and anemia, TSAT was significantly different between PPI users and non-users (adjusted difference, -0.82% [95% CI: -1.56 to -0.07]). CONCLUSIONS: This study showed the associations between PPI and ERI, ESA dose, and TSAT in hemodialysis patients; physicians should consider anemia's associations with PPIs in hemodialysis patients.

Hypoxia-inducible factor prolyl hydroxylase inhibitors for anaemia in chronic kidney disease: a document by the European Renal Best Practice board of the European Renal Association.

Anaemia is a common complication of chronic kidney disease (CKD) and is associated with poor long-term outcomes and quality of life. The use of supplemental iron, erythropoiesis stimulating agents (ESAs) and blood transfusions has been the mainstay of treatment of anaemia in CKD for more than three decades. Despite available treatments, CKD patients with anaemia are undertreated and moderate-to-severe anaemia remains prevalent in the CKD population. Anaemia has consistently been associated with greater mortality, hospitalisation, cardiovascular events, and CKD progression in patients with CKD, and the risk increases with anaemia severity. Hypoxia-inducible factor (HIF) prolyl hydroxylase (PH) inhibitors have a novel mechanism of action by mimicking the body's response to hypoxia and have emerged as an alternative to ESAs for the treatment of anaemia in CKD. Their efficacy in correcting and maintaining haemoglobin has been demonstrated in over 30 phase 3 clinical trials. Additionally, HIF activation results in various pleiotropic effects beyond erythropoiesis with cholesterol reduction and improved iron homeostasis and potential anti-inflammatory effects. The long-term safety of these agents, particularly with respect to cardiovascular and thromboembolic events, and their possible effect on tumor growth requires to be fully elucidated. This document presents in detail the effects of HIF-PH inhibitors, describes their mechanisms of action and pharmacologic properties, and discusses their place in the treatment of anaemia in CKD according to the available evidence.

Efficacy of erythropoietin as a neuroprotective agent in CKD-associated cognitive dysfunction: A literature systematic review.

Patients with chronic kidney disease (CKD) often experience mild cognitive impairment and other neurocognitive disorders. Studies have shown that erythropoietin (EPO) and its receptor have neuroprotective effects in cell and animal models of nervous system disorders. Recombinant human EPO (rHuEPO), commonly used to treat anemia in CKD patients, could be a neuroprotective agent. In this systematic review, we aimed to assess the published studies investigating the cognitive benefits of rHuEPO treatment in individuals with reduced kidney function. We comprehensively searched Pubmed, Cochrane Library, Scopus, and Web of Science databases from 1990 to 2023. After selection, 24 studies were analyzed, considering study design, sample size, participant characteristics, intervention, and main findings. The collective results of these studies in CKD patients indicated that rHuEPO enhances brain function, improves performance on neuropsychological tests, and positively affects electroencephalography measurements. These findings suggest that rHuEPO could be a promising neuroprotective agent for managing CKD-related cognitive impairment.

Erythropoiesis and estimated fluid volume regulation following initiation of ipragliflozin treatment in patients with type 2 diabetes mellitus and chronic kidney disease: A post-hoc analysis of the PROCEED trial.

AIMS: To analyse the changes in erythropoietic and estimated fluid volume parameters after the initiation of ipragliflozin, a sodium-glucose co-transporter 2 inhibitor, in patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD). METHODS: This was a post-hoc analysis of the PROCEED trial, which evaluated the effect of 24-week ipragliflozin treatment on endothelial dysfunction in patients with T2DM and CKD. We evaluated the changes in erythropoietic and estimated fluid volume parameters from baseline to 24 weeks post-treatment in 53 patients who received ipragliflozin (ipragliflozin group) and 55 patients with T2DM and CKD without sodium-glucose co-transporter 2 inhibitors (control group), a full analysis set of the PROCEED trial. RESULTS: The increases in haemoglobin [estimated group difference, 0.5 g/dl; 95% confidence interval (CI), 0.3-0.8; p < .001], haematocrit (estimated group difference, 2.2%; 95% CI, 1.3-3.1; p < .001) and erythropoietin (estimated log-transformed group difference, 0.1; 95% CI, 0.01-0.3; p = .036) were significantly greater in the ipragliflozin group than those in the control group. Ipragliflozin treatment was significantly associated with an increase in erythropoietin, independent of the corresponding change in haemoglobin (ß = 0.253, p < .001) or haematocrit (ß = 0.278, p < .001). Reductions in estimated plasma volume (estimated group difference, -7.94%; 95% CI, -11.6 to -4.26%; p < .001) and estimated extracellular volume (estimated group difference, -181.6 ml; 95% CI, -275.7 to -87.48 ml; p < .001) were significantly greater in the ipragliflozin group than those in the control group. CONCLUSIONS: Erythropoiesis was enhanced and estimated fluid volumes were reduced by ipragliflozin in patients with T2DM and CKD. CLINICAL TRIAL: PROCEED trial (registration number: jRCTs071190054).

Discovery of DS44470011: An oral hypoxia-inducible factor prolyl hydroxylase inhibitor for the treatment of renal anemia.

Inhibition of the hypoxia-inducible factor prolyl hydroxylase (HIF-PHD) represents a promising strategy for discovering next-generation treatments for renal anemia. We identified a pyrimidine core with HIF-PHD inhibitory activity based on scaffold hopping of FG-2216 using crystal structures of HIF-PHD2 in complex with compound. By optimizing the substituents at the 2- and 6- positions of the pyrimidine core, we discovered DS44470011, which improves the effectiveness of erythropoietin (EPO) release in cells. Oral administration of DS44470011 to cynomolgus monkeys increased plasma EPO levels.

Biological variation of inflammatory and iron metabolism markers in high-endurance recreational athletes; are these markers useful for athlete monitoring?

OBJECTIVES: To deliver biological variation (BV) data for serum hepcidin, soluble transferrin receptor (sTfR), erythropoietin (EPO) and interleukin 6 (IL-6) in a population of well-characterized high-endurance athletes, and to evaluate the potential influence of exercise and health-related factors on the BV. METHODS: Thirty triathletes (15 females) were sampled monthly (11 months). All samples were analyzed in duplicate and BV estimates were delivered by Bayesian and ANOVA methods. A linear mixed model was applied to study the effect of factors related to exercise, health, and sampling intervals on the BV estimates. RESULTS: Within-subject BV estimates (CVI) were for hepcidin 51.9 % (95 % credibility interval 46.9-58.1), sTfR 10.3 % (8.8-12) and EPO 27.3 % (24.8-30.3). The mean concentrations were significantly different between sex, but CVI estimates were similar and not influenced by exercise, health-related factors, or sampling intervals. The data were homogeneously distributed for EPO but not for hepcidin or sTfR. IL-6 results were mostly below the limit of detection. Factors related to exercise, health, and sampling intervals did not influence the BV estimates. CONCLUSIONS: This study provides, for the first time, BV data for EPO, derived from a cohort of well-characterized endurance athletes and indicates that EPO is a good candidate for athlete follow-up. The application of the Bayesian method to deliver BV data illustrates that for hepcidin and sTfR, BV data are heterogeneously distributed and using a mean BV estimate may not be appropriate when using BV data for laboratory and clinical applications.

Real-world evidence on the dosing and safety of C.E.R.A. in pediatric dialysis patients: findings from the International Pediatric Dialysis Network registries.

BACKGROUND: This retrospective real-world study used data from two registries, International Pediatric Peritoneal Dialysis Network (IPPN) and International Pediatric Hemodialysis Network (IPHN), to characterize the efficacy and safety of continuous erythropoietin receptor activator (C.E.R.A.) in pediatric patients with chronic kidney disease (CKD) on peritoneal dialysis (PD) or hemodialysis (HD). METHODS: IPPN and IPHN collect prospective data (baseline and every 6 months) from pediatric PD and HD centers worldwide. Demographics, clinical characteristics, dialysis information, treatment, laboratory parameters, number and causes of hospitalization events, and deaths were extracted for patients on C.E.R.A. treatment (IPPN: 2007-2021; IPHN: 2013-2021). RESULTS: We analyzed 177 patients on PD (median age 10.6 years) and 52 patients on HD (median age 14.1 years) who had ≥ 1 observation while being treated with C.E.R.A. The median (interquartile range [IQR]) observation time under C.E.R.A. exposure was 6 (0-12.5) and 12 (0-18) months, respectively. Hemoglobin concentrations were stable over time; respective means (standard deviation) at last observation were 10.9 (1.7) g/dL and 10.4 (1.7) g/dL. Respective median (IQR) monthly C.E.R.A. doses at last observation were 3.5 (2.3-5.1) µg/kg, or 95 (62-145) µg/m2 and 2.1 (1.2-3.4) µg/kg, or 63 (40-98) µg/m2. Non-elective hospitalizations occurred in 102 (58%) PD and 32 (62%) HD patients. Seven deaths occurred (19.8 deaths per 1000 observation years). CONCLUSIONS: C.E.R.A. was associated with efficient maintenance of hemoglobin concentrations in pediatric patients with CKD on dialysis, and appeared to have a favorable safety profile. The current analysis revealed no safety signals.

Roxadustat Versus Erythropoietin: The Comparison of Efficacy in Reversing Ventricular Remodeling in Dialysis Patients with Anaemia.

Background: Renal anaemia and left ventricular hypertrophy are the main complications of chronic kidney disease and are shared among dialysis patients. This retrospective study aimed to compare the efficacies of the hypoxia-inducible factor prolyl hydroxylase inhibitor roxadustat and recombinant human erythropoietin in reversing ventricular remodeling in dialysis patients with renal anaemia. Methods: A total of 204 participants underwent baseline examinations, including echocardiograms and laboratory tests, before being administered either treatment for at least 24 weeks from January 2018 to October 2021, after which follow-up examinations were conducted at 6 months. Propensity score matching based on key variables included age, gender, cardiovascular diseases, cardiovascular medications, dialysis course and the vascular access at baseline was performed to include populations with similar characteristics between groups. Results: In total, 136 patients were included with roxadustat or recombinant human erythropoietin. The left ventricular mass index after treatment with roxadustat and recombinant human erythropoietin both significantly decreased after 6 months, but there was no significant difference in the change in left ventricular mass index between the two groups. In addition, the left ventricular end-diastolic diameters and left ventricular wall thickness, systolic blood pressure, and diastolic blood pressure significantly decreased in the roxadustat group. Roxadustat and recombinant human erythropoietin also increased haemoglobin significantly, but there was no significant difference in the change in haemoglobin between the two groups. The results of multiple linear regression showed that the change in haemoglobin was independent factor affecting the improvement of left ventricular mass index. Conclusions: The increase of haemoglobin was associated with improving left ventricular hypertrophy in dialysis patients. However, the beneficial effects between roxadustat and recombinant human erythropoietin on left ventricular mass index did not show clear superiority or inferiority in six months.

A very-low-calorie ketogenic diet normalises obesity-related enhanced levels of erythropoietin compared with a low-calorie diet or bariatric surgery.

PURPOSE: Nutritional ketosis synergistically with body-weight loss induced by a very-low-calorie ketogenic diet (VLCKD) has proven to be effective in improving obesity-related pathophysiology. Recently, growing attention has been focused on the relation between erythropoietin (EPO) and obesity. Thus, this study aims to investigate whether nutritional ketosis and weight loss induced by a VLCKD modify the circulating levels of EPO in patients with obesity in comparison with the effect of low-calorie diet (LCD) or bariatric surgery (BS). METHODS: EPO levels, iron status and body composition parameters were evaluated in 72 patients with overweight or obesity and 27 normal-weight subjects at baseline and after the three different weight-reduction therapies (VLCKD, LCD and BS) in 69 patients with excess body weight. ß-hydroxybutyrate levels were also measured in the VLCKD group. The follow-up was established at 2-3 months and 4-6 months. RESULTS: It was found that EPO levels were higher in morbid obesity and correlated with higher basal weight, fat mass (FM) and fat-free mass (FFM) in the overall sample. High baseline EPO levels were also correlated with higher impact on the course of weight loss and changes in FM and FFM induced by the three weight-loss interventions. Furthermore, the VLCKD induced a decrease in EPO levels coinciding with maximum ketosis, which was maintained over time, while statistically significant changes were not observed after LCD and BS. CONCLUSION: The obesity-related increased EPO levels are restored after VLCKD intervention at the time of maximum ketosis, suggesting a potential role of the nutritional ketosis induced by the VLCKD. Baseline EPO levels could be a biomarker of response to a weight-loss therapy.

Erythropoietin hyporesponsiveness in non-alcoholic fatty liver disease.

Treatment with erythropoietin (EPO) can correct anaemia in chronic kidney disease (CKD) patients; however, up to 10% exhibit resistance or hyporesponsiveness to EPO. Non-alcoholic fatty liver disease (NAFLD), prevalent liver disease in CKD patients, may limit EPO response because of thrombopoietin deficiency, iron homeostasis disorder and inflammation. Therefore, we hypothesized NAFLD is a risk factor for EPO responsiveness. To test our hypothesis, we evaluated the effect of EPO in healthy rats and rats with NAFLD induced by a high-fat, high-carbohydrate (HFHC) diet. After 12 weeks on the HFHC diet, NAFLD rats showed lower erythroid response to EPO treatment than healthy rats. We, then, determined that the primary cause of EPO hyporesponsiveness could be iron deficiency associated with inflammation, which reduces erythroid cell production. Specifically, the concentrations of hepcidin, ferritin, transferrin and white blood cells in NAFLD rats were 12.8-, 16.4-, 2.51- and 1.40-fold higher than those in healthy rats, respectively. However, erythroid cell types in the bone marrow of NAFLD rats were significantly reduced. In conclusion, our data suggest that NAFLD could be a risk factor for EPO responsiveness, which is attributed to functional iron deficiency associated with inflammation.