Erythropoiesis-stimulating Agents Resistance Research Articles

Pentoxifylline improves anemia through its novel effect on hypoxia-inducible factor-2 alpha in hemodialysis patients: a randomized, double-blind, placebo-controlled clinical trial

ABSTRACT Objectives This randomized, double-blind, placebo-controlled clinical trial aimed to prospectively examine the effect of pentoxifylline (PTX) on hypoxia-inducible factor-2 alpha (HIF-2α) and its role in controlling anemia in hemodialysis (HD) patients. Methods Eighty patients on HD were randomized to receive 400 mg of PTX or placebo twice daily for 6 months. The hemoglobin (Hb) and other hematologic parameters, the weekly erythropoiesis-stimulating agents (ESAs), and the ESA resistance index (ERI) were assessed monthly during the study. The HIF-2α, transforming growth factor-β1 (TGF-β1), and high-sensitivity C-reactive protein (hs.CRP) were measured before and after the intervention. Results In the pentoxifylline group, an appreciable increase in Hb from 9.7 (9.3, 10.3) g/dl to 10.5 (9.3, 11.4) g/dl and hematocrit (Hct) from 31.3 (29.6, 32.4)% to 33.2 (29.4, 35.9)% was observed after one month of PTX administration, and this effect was maintained over the study time (p < 0.001). This was along with a decrease in the ESA doses required from 8000 (8000, 11500) IU/wk to 4000 (2000, 8000) IU/wk (p < 0.001), and an improvement in the ERI from 11.6 (8.07, 16.97) IU/kg/wk/g/dl to 5.79 (2.01, 10.09) IU/kg/wk/g/dl (p < 0.001). Additionally, the HIF-2α increased significantly at the end of the intervention in patients who received PTX from 3245.35 (2886.8, 4691.56) pg/ml to 7208.75 (5382, 9182.7) pg/ml, while TGF-β1 and hs.CRP decreased significantly from 657.78 (539.78, 1146.62) pg/ml and 88.08 (39.93, 100.4) mg/l to 329.94 (228.67, 793.18) pg/ml and 48.65 (34.44, 84.61) mg/l, respectively. The percent changes in HIF-2α, TGF-β1, and hs.CRP levels in the pentoxifylline group were also statistically significant in comparison with the placebo group. Conclusions PTX could be a promising agent for correcting anemia in HD patients via increasing HIF-2α levels. Clinical trial registration Clinicaltrials.gov, February 2023, registry number: NCT05708248.

Severe Hyporesponsiveness to Erythropoiesis-Stimulating Agents in Patients on Chronic Hemodialysis-Reconsidering the Relationship with Thrombo-Inflammation and Oxidative Stress.

Besides a multitude of consequences patients on chronic renal replacement therapy have, anemia is one of the most prominent factors making a significant number of patients dependent on erythropoiesis-stimulating agent (ESA) therapy. The aim of this study was to examine the relationship between the levels of a broad spectrum of thrombo-inflammatory and oxidative stress-related biomarkers and the presence and level of ESA hyporesponsiveness in patients undergoing regular chronic hemodialysis. This cross-sectional study included 96 patients treated with chronic hemodialysis. Levels of several thrombo-inflammatory and oxidative stress-related biomarkers, as well as demographic, clinical, and laboratory analyses, were collected and analyzed based on the calculated value of the ESA-hyporesponsiveness index (EHRI). In the analyzed sample, 58 patients received ESAs. Of all the investigated parameters, only body mass index (BMI), level of plasminogen activator inhibitor-1, and level of L-type fatty acid binding protein (L-FABP) were observed as significant predictors of EHRI. A significant diagnostic potential for ESA resistance has been observed in BMI and L-FABP between ESA-resistant and ESA-non-resistant groups of patients (p = 0.004, area under the curve 0.763 and p = 0.014, area under the curve 0.712, respectively) with the cut-off values of 25.46 kg/m2 and 5355.24 ng/mL, respectively. Having a BMI of 25.46 kg/m2 or less and an L-FABP level higher than 5355.24 ng/mL were observed as significant predictors of ESA resistance (odds ratio 9.857 and 6.125, respectively). EHRI was positively predicted by low BMI and high levels of plasminogen activator inhibitor-1 and L-FABP. High levels of L-FABP and low BMI have been observed as strong predictors of ESA resistance.

Cutoff Value of Erythropoiesis-Stimulating Agent Resistance Index at Which Iron Replacement Therapy Is Expected to Be Effective

Cutoff Value of Erythropoiesis-Stimulating Agent Resistance Index at Which Iron Replacement Therapy Is Expected to Be Effective

Efficacy of sutimlimab for cold agglutinin disease in a patient on chronic hemodialysis.

Reports of cold agglutinin disease (CAD), an autoimmune hemolytic anemia, in dialysis patients are limited. Recently, sutimlimab for CAD was covered by insurance. Herein, we report a case in which sutimlimab was effective in the treatment of CAD in a patient undergoing hemodialysis (HD). The patient was a 73year-old Japanese man with an 11year history of HD for diabetic nephropathy. He was admitted to our hospital for examination and treatment of erythropoiesis-stimulating agent (ESA)-induced hyporesponsive anemia and fatigue, which was present in the previous year October to March when temperatures were cooler. The patient was diagnosed with hemolytic anemia based on decreased hemoglobin levels, elevated reticulocyte count, elevated lactate dehydrogenase levels, and decreased haptoglobin levels. Furthermore, he was diagnosed with CAD based on a positive direct antiglobulin test for C3 and cold agglutinin tests. The patient did not respond well to an elevated dialysate temperature or rituximab therapy. After initiating sutimlimab treatment, an increase in the hemoglobin level was observed despite a decrease in temperature, and his fatigue disappeared. Anemia in hemodialysis patients is generally renal; however, some ESA resistance exists, which may be due to hemolytic anemia. In this case, the use of sutimlimab was effective in controlling hemolytic anemia due to CAD.

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

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

Association between magnesium, erythropoietin resistance and mortality: the Japanese Dialysis Outcomes and Practice Patterns Study (J-DOPPS).

Limited data are now available to evaluate the relationship between serum magnesium level, anemia and mortality in the dialysis population. Using data from the Japanese Dialysis Outcomes and Practice Patterns Study (J-DOPPS) phases 5 and 6, we analyzed the association between serum magnesium (s-Mg) levels and the erythropoiesis-stimulating agents resistance index (ERI) as the primary outcome. To estimate the longitudinal relationship, a mixed-effect model was used with ERI at each 4-month period as the dependent variable and quintiles of s-Mg at the previous 4-month period as the independent variable. We also examined incidence of infectious events, and the all-cause and cardiovascular disease (CVD)-related deaths as secondary outcomes by Cox regression with quintiles of s-Mg at baseline. Of the 4776 participants in J-DOPPS, 1650 were included in the analysis. The median of s-Mg at baseline was 2.5 mg/dL. A significant linear association of s-Mg with ERI (P for trend <.001) was revealed. Low and high s-Mg levels were not associated with the clinical outcomes of interest, except for the highest quintile of s-Mg being significantly associated with lower incidence of all-cause mortality and CVD-related deaths compared with the middle (reference) quintile. We observed that lower s-Mg levels subsequently induced higher ERI and that mild higher s-Mg levels were possibly associated with good rather than poor outcomes in Japanese hemodialysis patients. Adjustment of s-Mg levels may be proposed as a new strategy at a low cost and risk to reduce the risk of premature mortality.

Factors affecting responsiveness of vadadustat in patients with anemia associated with chronic kidney disease: a post-hoc subgroup analysis of Japanese phase 3 randomized studies

BackgroundVadadustat is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor developed for treating anemia in chronic kidney disease (CKD). The purpose of this post-hoc analysis was to investigate the factors affecting the responsiveness to vadadustat in anemia patients with nondialysis-dependent (NDD) or hemodialysis-dependent (HDD) CKD in two Japanese phase 3 studies.MethodsOf 151 and 162 patients enrolled in NDD-CKD and HDD-CKD studies, 136 and 140 patients, respectively, were included and divided into subgroups for the analysis. To assess vadadustat responsiveness, the resistance index was defined as the mean body weight-adjusted dose of vadadustat (mg/kg) at weeks 20–24 divided by the mean hemoglobin (g/dL) at weeks 20–24. Multivariate analysis was performed to identify the variables affecting the resistance index.ResultsIndependent factors identified as determinants for better response to vadadustat were as follows: high baseline hemoglobin, low baseline eGFR, high week-20–24 ferritin, and CKD not caused by autoimmune disease/glomerulonephritis/vasculitis in NDD-CKD; and male sex, high baseline C-reactive protein, and low baseline erythropoiesis-stimulating agent resistance index (ERI) in HDD-CKD.ConclusionsIn this post-hoc analysis, several factors were identified as affecting the response to vadadustat. These results may provide useful information leading to an appropriate dose modification for vadadustat.Clinical trial registrationNCT03329196 (MT-6548-J01) and NCT03439137 (MT-6548-J03).

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.

Predictors of Hyporesponsiveness to Erythropoiesis-Stimulating Agents in Patients with Non-Dialysis-Dependent Chronic Kidney Disease (RADIANCE-CKD Study)

Introduction: Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) has been associated with increased mortality and cardiovascular events in patients with chronic kidney disease. We hypothesized that the prediction of ESA resistance during ESA administration would be very useful in deciding on a treatment plan. Methods: Patients enrolled in a randomized controlled trial to evaluate renal prognosis in anemic patients with non-dialysis-dependent chronic kidney disease with hyporesponsiveness to ESA were included; the patients had different target hemoglobin levels. A landmark analysis was performed at 3 months into the study. To construct a predictive model for the severe ESA hypo-responder group, in which there was no increase in hemoglobin even with active treatment, background factors and serum test items that affect anemia at study entry were included in a logistic regression model, the area under the curve (AUC) and 95% confidence intervals (CI) were estimated, and sensitivity and specificity were calculated. This study was a post hoc sub-analysis of a randomized controlled trial. Results: The AUC for the 19 existing risk factors as predictors was 0.783 (95% CI: 0.711–0.855). Among the 19 risk factors, the combination of six factors (hemoglobin level, systolic blood pressure, weight, gender, smoking status, and hypertensive retinopathy) with the largest χ² statistics were selected by multiple logistics regression. The AUC for these 6 predictors was 0.716 (95% CI: 0.634–0.799). To the six existing risk factors, five serum test items that affect anemia (vitamin B12, vitamin B6, folic acid, parathyroid hormone, and 25-hydroxyvitamin D) were added, for a total of 11 risk factors, with a similar AUC of 0.736 (95% CI: 0.655–0.817), sufficient to predict ESA resistance. Conclusions: Our results suggest that existing risk factors and serum test items can be used to predict ESA resistance in patients with non-dialysis-dependent chronic kidney disease on ESA.

Roxadustat alleviates the inflammatory status in patients receiving maintenance hemodialysis with erythropoiesis-stimulating agent resistance by increasing the short-chain fatty acids producing gut bacteria

BackgroundHypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHIs) have improved the treatment of renal anemia, especially in patients resistant to erythropoiesis-stimulating agents (ESAs). HIF facilitates maintain gut microbiota homeostasis, which plays an important role in inflammation and iron metabolism, which are in turn key factors affecting ESA resistance. The current study aimed to investigate the effects of roxadustat on inflammation and iron metabolism and on the gut microbiota in patients with ESA resistance.MethodsWe conducted a self-controlled, single-center study including 30 patients with ESA resistance undergoing maintenance hemodialysis. All patients received roxadustat without iron agents for renal anemia. Hemoglobin and inflammatory factors were monitored. Fecal samples were collected before and after 3 months’ administration and the gut microbiota were analyzed by 16S ribosomal RNA gene sequencing.ResultsHemoglobin levels increased after treatment with roxadustat for 3 months (P < 0.05). Gut microbiota diversity and abundance also changed, with increases in short-chain fatty acid (SCFA)-producing bacteria (Acidaminococcaceae, Butyricicoccus, Ruminococcus bicirculans, Ruminococcus bromii, Bifidobacterium dentium, Eubacterium hallii) (P < 0.05). Serum SCFA levels also increased (P < 0.05). Inflammatory factors, including interleukin (IL)-1, IL-6, tumor necrosis factor (TNF)-α, interferon-γ, and endotoxin gradually decreased (P < 0.05). Serum hepcidin, ferritin, and total and unsaturated iron-binding capacities decreased (P < 0.05), while soluble transferrin receptor levels increased at each time point (P < 0.05). There were no significant differences in serum iron and transferrin saturation at each time point. The abundance of Alistipes shahii was significantly negatively correlated with IL-6 and TNF-α (P < 0.05).ConclusionsRoxadustat alleviated renal anemia in patients with ESA resistance by decreasing inflammatory factors and hepcidin levels and improving iron utilization. These effects were at least partly mediated by improved diversity and abundance of SCFA-producing gut bacteria, probably via activation of HIF.

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

Current guidelines establish the same hemoglobin (Hb) and iron biomarkers targets for hemodialysis (HD) and peritoneal dialysis (PD) in patients receiving erythropoiesis-stimulating agents (ESAs) even though patients having PD are usually younger, more active and less comorbid. Unfortunately, specific renal anemia [anemia in chronic kidney disease (aCKD)] trials or observational studies on PD are scanty. The aims of this study were to describe current aCKD management, goals and adherence to clinical guidelines, identifying opportunities for healthcare improvement in PD patients. This was a retrospective, nationwide, multicentre study including patients from 19 PD units. The nephrologists collected baseline data, demographics, comorbidities and data related to anemia management (laboratory values, previously prescribed treatments and subsequent adjustments) from electronic medical records. The European adaptation of KDIGO guidelines was the reference for definitions, drug prescriptions and targets. A total of 343 patients (mean age 62.9years, 61.2% male) were included; 72.9% were receiving ESAs and 33.2% iron therapy [20.7% intravenously (IV)]. Eighty-two patients were receiving ESA without iron therapy, despite 53 of them having an indication according to the European Renal Best Practice guidelines. After laboratory results, iron therapy was only started in 15% of patients. Among ESA-treated patients, 51.9% had an optimal control [hemoglobin (Hb) 10-12g/dL] and 28.3% between 12-12.9g/dL. Seventeen patients achieved Hb >13g/dL, and 12 of them remained on ESA after overshooting. Only three patients had Hb <10g/dL without ESAs. Seven patients (2%) met criteria for ESA resistance (epoetin dose >300IU/kg/week). The highest tertile of erythropoietin resistance index (>6.3 UI/kg/week/g/dL) was associated with iron deficiency and low albumin corrected by renal replacement therapy vintage and hospital admissions in the previous 3months. Iron therapy continues to be underused (especially IV). Low albumin, iron deficiency and prior events explain most of the ESA hyporesponsiveness. Hb targets are titrated to/above the upper limits. Thus, several missed opportunities for adequate prescriptions and adherence to guidelines were identified.

Direct antiglobulin test-negative autoimmune hemolytic anemia associated with erythropoiesis stimulating agent resistance in a CKD patient with IgG4-related disease: A case report

Rationale: Direct antiglobulin test (DAT)-negative autoimmune hemolytic anemia (AIHA) is an important differential diagnosis for erythropoiesis-stimulating agents-resistant renal anemia with hemolysis. Patient concerns: An 82-year-old female with a past medical history of diabetes, end-stage kidney disease (estimated glomerular filtration rate: 6.9 mL/min/1.73 m2), post-transcatheter aortic valve implantation, and IgG4-related retroperitoneal fibrosis on prednisolone therapy was referred to our department for assessment of severe anemia. The patient underwent immunohematological testing for serological evaluation. Diagnoses: DAT-negative AIHA and IgG4-RD was established based on DAT-negative and immunohematological tests. Interventions: Glucocorticoid was administered to the patient. Outcomes: The patient’s condition including hemoglobin level was relieved. Lessons: In chronic kidney disease, AIHA may contribute to the development of severe anemia and erythropoiesis-stimulating agents-resistance, irrespective of the results of Coombs test. Reticulocytosis, undetectable haptoglobin and a fall in hemoglobinA1c despite sustained hyperglycemia may be a clue to the diagnosis of hemolysis.

Regional Variation of Erythropoiesis-Stimulating Agent Hyporesponsiveness in the Global Daprodustat Dialysis Study (ASCEND-D)

Introduction: Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) affects 10–15% of the chronic dialysis population. We explored baseline characteristics and predictors of ESA hyporesponsiveness in a global randomized cardiovascular outcomes study comparing an investigational hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI), daprodustat, with conventional ESA treatment. Methods: ASCEND-D (NCT02879305) recruited 2,964 chronic dialysis patients receiving ESA treatment (standardized to weekly intravenous [IV] epoetin) who were iron replete at baseline. The primary ESA hyporesponsiveness definition was an ESA Resistance Index (ERI, ESA units/kg/week/hemoglobin g/L) ≥2 or IV standardized ESA dose ≥450 units/kg/week. Predictors of ESA hyporesponsiveness were determined using a multivariable regression model. Alternative hyporesponder definitions were explored. Results: Using the primary definition, 354 (12%) patients were ESA hyporesponsive. Geographic region, notably Latin America, lower baseline body mass index and transferrin saturation, younger age, lower albumin concentration, and a higher baseline IV iron dose were identified as strongly associated (p < 0.001) with ESA hyporesponsiveness. Additional predictors of ESA hyporesponsiveness included female sex (p = 0.010), history of heart failure (p = 0.035), longer dialysis vintage (p = 0.077), smoking status (p = 0.247), aspirin use (p = 0.121), and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use (p = 0.214). Conclusion: This is the first global HIF-PHI study to report prespecified definitions and predictors of ESA hyporesponsiveness. While most of the predictors identified in our study have been previously reported, geographic region stands out as an unexpected finding, meriting further investigation.

Roxadustat: Do we know all the answers?

Anemia is a common complication of chronic kidney disease (CKD), and its prevalence rises as the disease progresses. Intravenous or subcutaneous erythropoiesis-stimulating agents (ESAs) are advised to treat CKD-associated anemia, since shortage of erythropoietin (EPO) and iron are the main cause of anemia. However, ESA resistance and safety have spurred a lot of interest in the development of alternate anemia therapies. Roxadustat, an orally administered hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI) that increases erythropoiesis and may modulate iron metabolism, was recently licensed in China, Chile, South Korea, Japan and the European Union for the treatment of CKD-related anemia. Despite this, clinical trials have shown a number of adverse effects, including cardiovascular disease, hyperkalemia, and infections. In addition, of concern is roxadustat's possible effects on other organs and systems. In this review, based on clinical evidence, we discuss the potentially detrimental effects of roxadustat to the known biology on systems other than kidney, and the need for long-term follow-up in order for roxadustat to be approved in more countries in the future.

Responsiveness to an erythropoiesis-stimulating agent is correlated with body composition in patients undergoing chronic hemodialysis.

Resistance to erythropoiesis-stimulating agents (ESA) is associated with adverse outcomes in patients undergoing chronic hemodialysis. However, the impact of body composition on ESA response remains uncertain. This study retrospectively investigated whether there is an association between the ESA resistance index (ERI) and body composition in patients undergoing chronic hemodialysis. Multifrequency bioelectrical impedance analysis was used to measure body composition every six months. The ERI was calculated by dividing the weekly body weight-adjusted erythropoietin dose by the hemoglobin concentration. The ERI values were recorded every three months. A total of 123 patients were followed up for 24 (interquartile range 5, 75) months. The ERI was negatively correlated with body mass index, arm circumference, arm muscle circumference, body fat percentage, and visceral fat area (P = 0.057, 0.001, 0.017, 0.063, and 0.041, respectively). Patients with a higher mean ERI during the study period had an increased risk of all-cause mortality, cardiovascular events, and infection requiring hospitalization than those with a lower mean ERI (P = 0.027, 0.021, and 0.037, respectively). We also evaluated the association between the slope of body composition parameters and the ERI trend over time and found that the ERI increased over time in patients who had an increased ratio of extracellular water to total body water (P = 0.002) as well as decreased arm circumference, arm muscle circumference, visceral fat area, and phase angle (P = 0.001, P < 0.001, P = 0.036, and 0.002). ESA responsiveness appears to be associated with body composition in patients undergoing chronic hemodialysis. Therefore, measures improving body composition, such as nutrition and exercise, may have a favorable effect on the response to ESA.

Characteristics and Distribution of Erythroid Progenitors and Precursors Correlate with Erythropoiesis Stimulating Agents (ESAs) Response in Lower Risk Myelodysplastic Syndromes

Myelodysplastic syndromes (MDS) are an heterogenous group of clonal myeloid disorders characterized by dysplastic ineffective hematopoiesis, peripheral blood cytopenias and a variable risk of progression to acute myeloid leukemia (AML) evaluated by IPSS-R score. Early stage erythropoiesis is dependent on growth factors like EPO, whereas late erythroid differentiation is iron-dependent. The entire process requires a fine regulation between apoptosis and cell survival. Anemia is the most common cytopenia in IPSS-R lower risk MDS (LR-MDS) and the mechanism underlying dyserythropoiesis is multifactorial, leading to apoptosis of erythroid progenitors and precursors. LR-MDS anemia is mainly treated with ESAs (e.g., Erythropoietin or EPO), but response is not optimal and eventually patients will suffer from chronic anemia and transfusion dependence. Moreover, the only strong predictor of ESAs treatment is the endogenous concentration of serum EPO (sEPO). The primary aim of this study was to detect quantitative and qualitative flow cytometry (FC) alterations of erythroid populations in the bone marrow (BM) of LR-MDS patients associated with resistance or response to ESAs and compared them with age-matched non cytopenic BM controls (CTRLs, 6). Secondly, we wanted to investigate if different WHO diagnostic MDS subgroups displayed specific pattern of erythroid maturation and/or FC abnormalities. We selected 97 LR-MDS anemic patients treated with ESAs at MDS Unit, Hematology dpt. AOU Careggi (Florence) and divided them according to type of ESAs response (e.g., primary refractory, PR; long responders, LR, with DOR longer than 24 months and secondary refractory, SR, with DOR shorter than 24 months). Baseline BM FC analysis was performed using an erythroid panel containing antibodies for CD33, CD34, CD36, HLA-DR, CD45, CD71, CD105, CD117. We also measured the coefficient of variance (CV) of CD71 and CD36 to assess qualitative FC abnormalities within the erythroid populations. We then identified all stages of erythroid maturation from A) CD34+ committed erythroid cells (CD34+, CD45dim, CD117+, CD71+, CD33+, HLA-DR +), or erythroid progenitors (COM-E), expressed both as fraction of all CD34+ cells and all 117+ progenitor cells, to B) CD34- erythroid precursors (from proerythroblasts, PROE, to orthochromatic erythroblasts). CV CD71 was increased in PR patients compared to CTRLs (p=0,009) and to responders (p=0,008). COM-E/tot.CD34+ cells were increased in all response categories, but there was a significant trend of higher values in LR vs. PR (p=0,055). Finally, (COM-E + PROE)/tot.117+ progenitors were only enriched in LR compared to CTRLs (p=0,009). Regarding WHO subgroups, MDS 5q- displayed a decrease in COM-E/CD34+ cells and in (COM-E + PROE)/tot.117+ cells compared to MDS-RS (p=0,00094 and p=0,009 respectively) and to CTRLs for the latter population (p=0,03). Moreover, total erythroid precursors were significantly reduced compared to MDS-SLD, -MLD and -RS. MDS-RS showed a marked erythroid hyperplasia and elevation of CV CD71 compared to CTRLs (p=0,0079 and p=0,024 respectively). Taken together, these results show that in LR-MDS, the increase of CV CD71 in erythroid cells is associated with resistance to ESAs, whereas response to ESAs is present in cases with enriched EPO sensitive COM-E and PROE populations compared to CTRLs, especially for LR vs PR (p=0,055). Finally, MDS-5q- and MDS-RS were the WHO subgroups with the highest rate of PR in our cohort (46% and 59% respectively), irrespective of sEPO. These 2 subgroups of MDS exhibited different repartition of erythroid subpopulations with characteristics associated with ESAs resistance. In 5q- COM-E and PROE were depauperate and, consequently, erythroid precursors reduced, while MDS-RS displayed an expansion of erythroid precursors and higher CV of CD71 compared to CTRLs. Finally, these FC parameters, easily and rapidly assessed at baseline BM evaluation in MDS patients, correlate with response to ESAs and with different WHO subgroups. FC erythroid abnormalities could partly explain the complex pathobiology underlying dyserythropoiesis and its treatment. The different repartition of erythroid progenitors observed could lead to molecular and transcriptome analyses focused on these altered subpopulations in order to investigate the exact mechanism of anemia in LR-MDS(s). Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Effect of roxadustat on serum metabolome and lipidome in patients with end-stage renal disease and erythropoiesis-stimulating agent resistance.

Roxadustat is a newly marketed hypoxia-inducible factor prolyl hydroxylase inhibitor used to treat anemia in patients with end-stage renal disease (ESRD). While clinical trials have demonstrated the therapeutic effects of roxadustat in patients with ESRD who are resistant to erythropoiesis-stimulating agents (ESAs), its metabolic effects are still unclear. Thirty-two individuals with ESRD and ESA resistance from the Blood Purification Center of Dalian Municipal Central Hospital were included. A total of 96 fasting serum samples were obtained from participants before treatment with roxadustat, and after treatment for 15 and 30 days. Ultra-high performance liquid chromatography-mass spectrometry-based metabolomics and lipidomics strategies were applied to investigate the effects of roxadustat on serum metabolism. A total of 255 metabolites and 444 lipid molecular species were detected and quantified. Sphingolipids and phospholipids decreased significantly during treatment, possibly associated with changes in phospholipid and ceramide metabolism. Bile acid levels decreased and cholic acid/chenodeoxycholic acid increased, indicating changes in gut microbiota and bile acid metabolism. Amino acids also changed during the process of treatment. The present study showed sphingolipids, phospholipids, and bile acids were significantly altered, which may be associated with a changed metabolism caused by roxadustat. This approach provided a powerful tool for exploring the mechanisms of ESA resistance in ESRD patients and may represent a promising strategy for elucidating the complex therapeutic mechanisms of other drugs.

MO796: Short-Term Effect of Roxadustat Combined With Erythropoiesis Stimulating Agents (ESAS) Treatment for Anemia in Patients Undergoing Hemodialysis With ESA Resistance

Abstract BACKGROUND AND AIMS Renal anemia is a common complication of chronic kidney disease (CKD) that can decrease the quality of life of patients, especially for patients with maintenance hemodialysis (MHD). The current standard treatment for renal anemia consists of iron plus erythropoiesis-stimulating agents (ESAs). However, high-dose ESA supplementation may cause an increase in blood pressure and induce cardiovascular events and death [1]. Roxadustat (FG-4592) is a new small-molecule oral medication for the treatment of renal anemia that may improve anemia by increasing endogenous erythropoiesis, transferrin receptor expression, and iron absorption [2]. Currently, the use of roxadustat in the treatment of renal anemia is still being explored. Our study aimed to observe the short-term efficacy of roxadustat combined with ESAs on renal anemia in MHD patients with ESA resistance. METHOD This retrospective study included patients with renal anemia using roxadustat for the first time at West China Hospital of Sichuan University from September 2019 to March 2021. Study inclusion criteria: (1) MHD for &amp;gt;3 months (thrice weekly), (2) basal Hb ≤ 100 g/L and (3) ESAs therapy for &amp;gt;2 months, and the first time use of rosadustat for at least 1 month. We excluded those without hemoglobin data and those with a history of blood transfusion within the first month. Patients treated with roxadustat combined with ESAs were as an observation group, and those treated with roxadustat alone were included as a control group. RESULTS A total of 31 MHD patients were included, the baseline data was shown in Table 1. A total of 15 patients were treated with roxadustat combined with ESAs, and 16 patients were treated with roxadustat alone. In the first month, the mean hemoglobin level was significantly increased in the combined group (1.89 ± 1.45 g/dL) but decreased in the alone group (–0.25 ± 1.32 g/dL). According to an analysis of covariance (ANCOVA), after adjusting for basal hemoglobin levels, the combination therapy improved the hemoglobin level better than therapy alone (F = 6.329, P = .018). We defined the Hb response as: hemoglobin change from baseline ≥ 1 g/dL for patients with basal Hb &amp;gt;8.0 g/dL or ≥ 2.0 g/dL for patients with basal Hb ≤8.0 g/dL. Among the 15 patients treated with roxadustat combined with ESAs, 14 patients showed an increase in hemoglobin within the first month and 8 patients get the Hb response, with the Hb response rate of 53.3%. For the 16 patients treated with roxadustat alone, 7 patients showed an increase in hemoglobin, only 2 patients get the Hb response, with the Hb response rate 12.5%. Patients treated with roxadustat combined with ESAs had a higher Hb response rate (P = .023) than those with roxadustat alone within the first month. CONCLUSION Roxadustat combined with ESAs treatment might be more beneficial to improve renal anemia in MHD patients with ESA resistance during the first month of roxadustat therapy replacement.

Resistance to Erythropoiesis-Stimulating Agents among Patients on Hemodialysis Is Typically Transient

Introduction: This study examines factors associated with erythropoiesis-stimulating agent (ESA) hyporesponsiveness, the duration of ESA hyporesponsiveness, the frequency of new episodes, and variation across countries. Methods: We used international Dialysis Outcomes and Practice Patterns Study data from 2015 to 2018 (N = 26,656) to investigate changes in ESA Resistance Index (ERI), calculated as epoetin dose divided by [hemoglobin × body weight] in patients on hemodialysis. We illustrated the proportion of patients who moved to other ERI quintiles over 12 months, and we studied the incidence and duration of ESA resistance. We examined case-mix factors associated with quintiles of ERI. Results: Most patients migrated out of their original ERI quintile within 4 months. Only 22% of patients in the top quintile of ERI at baseline (4.4% of all patients) remained in the top quintile during all 12 months of follow-up. A total of 42% of patients manifested an upper-quintile ERI during at least 1 month. Median duration of a new episode of ESA resistance was 2 months. Catheter hemoaccess, elevated C-reactive protein, lower transferrin saturation, lower serum albumin concentration, and recent hospitalization occurred more frequently among patients in the highest ERI quintile at baseline. ERI values were highest in the USA, Italy, and Mideastern nations and lowest in Russia and Japan. Discussion/Conclusion: It is a misconception to envision a sizable, fixed segment of the population with permanent resistance to ESA – resistance fluctuates frequently. The implications of these findings for prescription of ESAs and of hypoxia-inducible factor-prolyl hydroxylase inhibitors are discussed.

Selenium Associates With Response to Erythropoiesis-Stimulating Agents in Hemodialysis Patients

IntroductionImpaired response to erythropoiesis-stimulating agents (ESAs) is associated with increased mortality in patients with end-stage kidney disease. However, the underlying mechanisms are not fully elucidated. Accumulating data reveal that selenium (Se), a trace element, plays a key role in stress erythropoiesis and erythrocyte homeostasis. We evaluated the relationship between serum Se levels and the response to ESAs in hemodialysis patients.MethodsIn this cross-sectional study, we determined serum Se levels in 173 hemodialysis patients. We analyzed the association of serum Se with ESA responsiveness, as defined by ESA resistance index.ResultsOf the study participants, 50% had lower Se levels than the population-based reference values. We found that serum Se levels were significantly and inversely correlated with erythropoiesis resistance index (ERI) but not transferrin saturation (TSAT) or ferritin levels. Multiple regression analyses confirmed the association between Se levels and ESA hyporesponsiveness, independently of other known factors, such as iron status, being female, and dialysis vintage (β = −0.11, P < 0.001). When patients were divided according to Se levels and iron status, both low serum Se (<10.5 μg/dl) and iron deficiency significantly affected the response to ESA. Conversely, serum Se levels were significantly different among groups when patients were divided according to ERI quartiles. The association of low serum Se with ESA hyporesponsiveness persisted after adjustment of confounding variables.ConclusionSerum Se levels are associated with the response to ESAs and can predict ESA resistance independently of iron status in Japanese hemodialysis patients. These data open the possibility to test whether Se supplementation reduces ESA demand.