Anemia in renal disease: diagnosis and management

Association Between Telomere Shortening and Erythropoietin Resistance in Patients with Chronic Kidney Disease Undergoing Hemodialysis

The relationship between telomere shortening and patients with chronic kidney disease (CKD) has recently been investigated. Although most patients respond adequately to erythropoiesis-stimulating agents (ESAs), approximately 10% do not, and this is referred to as ESA resistance. The aim of our study was to investigate the relationship between telomere shortening and erythropoietin resistance in patients with CKD on hemodialysis. This cross-sectional, comparative, analytical, and observational study was conducted in patients of both sexes over 18 years of age diagnosed with CKD. Two groups of patients were identified. The first group consisted of 40 patients receiving erythropoiesis-stimulating agents with erythropoietin resistance. The second group consisted of 40 patients with the same characteristics but without erythropoietin resistance. Telomere length was measured by real-time PCR. Eighty patients were included in the study. Mean hemoglobin levels were lower in the erythropoietin resistance group (8.8 ± 1.67 vs. 11.95 ± 1.81, p = 0.001). Differences were observed in hematocrit and albumin levels, which were lower in patients with erythropoietin resistance, while PTH levels were higher in this group (788 ± 538.47 vs. 535.65 ± 603.06, p = 0.001). A significant difference in telomere length (T/S) was observed between the two groups, with shorter telomere length in the erythropoietin resistance group (0.45 ± 0.04 vs. 0.56 ± 0.03, p = 0.01). Telomere shortening may be associated with anemia and erythropoietin resistance in patients with CKD undergoing hemodialysis. This relationship suggests the need to explore whether telomere length recovery improves the response to ESAs.

Correlation between ultrafiltration rate and hemoglobin level and erythropoietin response in hemodialysis patients

This study aimed to investigate the correlation between ultrafiltration rate (UFR) and hemoglobin levels and erythropoietin (EPO) response in patients receiving maintenance hemodialysis (MHD). 225 MHD patients were divided into three groups according to the UFR: < 10 ml/h/kg, 10-13 ml/h/kg, and >13 ml/h/kg. Clinical parameters and prognosis were compared among the groups. Multiple linear correlation and regression analyses were conducted. SPSS 26.0 (IBM, Chicago, IL, USA) was used to analyze all statistics. The UFR < 10 ml/h/kg group was older than the other groups (p < 0.05). The UFR > 13 ml/h/kg group had the highest SpKt/V (p < 0.05), monthly EPO dose/weight (p < 0.001), and EPO resistance index (p < 0.001), as well as the lowest dry weight (p < 0.001), BMI (p < 0.001), hemoglobin (p < 0.001), hematocrit (p < 0.05), and red blood cell count (p < 0.05). Multiple linear regression analysis showed that sex, dry weight, UFR, calcium, phosphorus, albumin, and C-reactive protein levels were associated with hemoglobin levels. Multivariate logistic regression analysis revealed that a higher UFR was associated with lower hemoglobin levels, while male sex and higher levels of calcium and albumin were associated with higher hemoglobin levels. High UFR is associated with more severe anemia and EPO resistance in MHD. This study provides new insights into anemia management in patients undergoing hemodialysis.

Prevalence and management of anemia and impact of treatment burden on health-related quality of life in chronic kidney disease and dialysis patients

Background

Anemia management in chronic kidney disease (CKD) is a significant challenge for healthcare professionals worldwide. The extensive management of CKD and its complications is directly linked with a substantial treatment burden, which impacts quality of life (QoL). This study aimed to assess the prevalence and management of anemia and to evaluate the treatment burden and its impact on the QoL of CKD and dialysis patients in Pakistan.

Methodology

A multicenter prospective observational study was conducted in three hospitals. A total of 170 patients were enrolled, with 156 available for follow-up after six months. Their prior consent was obtained. Each participant was interviewed in person and received a data collection form.

Results

At baseline, the prevalence of anemia among CKD (stage 3-5) and dialysis patients was 78.7% and 94.7%, respectively. Patients on dialysis used more erythropoietin stimulating agents (ESAs), with 38.6% at baseline and 40.8% by month six, compared to non-dialysis CKD patients. Oral iron was used by 6.2% of stage 3, 25% of stage 4, 20% of stage 5 patients, and 6.6% of dialysis patients at baseline. At the six-month follow-up, 42.8% of CKD and 33.8% of dialysis patients achieved the target hemoglobin level. Dialysis patients had a higher treatment burden compared to CKD at baseline (77.4±10.6 vs 59.3±13.3) and at six-month visit (79.3±11.1 vs 59.1±14.5). The multiple regression analysis showed that treatment burden had a significant association with age, disease duration, and comorbidity at baseline. There was a significant negative correlation between overall treatment burden and QoL, indicating that QoL decreases as treatment burden increases.

Conclusion

Anemia was prevalent, and its management was suboptimal in this study. The overall treatment burden score was high in dialysis patients, negatively affecting the QoL.

Admission Hemoglobin Associated with Increased Mortality in Hip Fracture Surgical Patients: An Observational Study

In hip fracture patients, who are mostly elderly, preexisting anemia can be worsened when combined with trauma and surgery. To this date, there is no unequivocal approach about transfusion thresholds. We analyzed hemoglobin (Hb) and hematocrit (Hct) levels at three time points in surgical patients with proximal femoral fractures (PFF) to see which levels were triggers for transfusions and whether transfusions were related to mortality after hospital discharge. A total of 956 patients were operated on from 1 January 2021 to 31 December 2022 at the University Hospital of Split and included in the study. There were more women (74%); 47% patients had admission Hb < 120 g/L. Transfusion was given preoperatively to 88, intraoperatively to 74 and postoperatively to 309 patients. Transfusion thresholds were as follows: Hb 84 g/L preoperatively, 99 intraoperatively and 83 postoperatively. After hospital discharge, 10.79% of patients died within the 1st month and 23% within 6 months. In the group of non-survivors, 60% of patients had admission Hb ≤ 117 g/L and the proportion of patients transfused preoperatively was two times higher. Preoperative transfusion thresholds could be set to higher levels for patients with surgically treated PFF. However, that could increase mortality even more. Further investigation is necessary.

Longitudinal evaluation of laboratory results and method precision in worldwide erythropoietin external quality assessments

Introduction: This study presents a longitudinal analysis of external quality assessment (EQA) results for erythropoietin (EPO) determinations conducted between 2017 and 2022 with a continuously increasing number of participating laboratories. The aim of this work was to evaluate participant performance and methodological aspects. Methods: In each of the eleven EQA surveys, a blinded sample set of lyophilized human serum containing one sample with lower EPO concentrations (L) and one with higher EPO concentrations (H) was sent to the participating laboratories. Results: A total of 1,256 measurements were included. The median (interquartile range) fraction of participants not meeting the criteria of acceptance set at 20% around the robust mean of the respective survey was 9.5% (6.1%-10.7%) (sample L) and 9.1% (5.8%-11.8%) (sample H) but lacked a clear trend in the observed period. Some surveys exhibited unusually high interlaboratory variation, suggesting interfering components in the EQA samples. Different immunological methods and reagent manufacturers also showed variability in measurement outcomes to some extent. Conclusion: These findings highlight the need for continuous quality assessment in EPO measurements to ensure patient safety and identify areas for further research and investigation.

Anemia of Chronic Kidney Disease-A Narrative Review of Its Pathophysiology, Diagnosis, and Management

Anemia is one of the most common chronic kidney disease (CKD) complications. It negatively affects patients' quality of life and clinical outcomes. The pathophysiology of anemia in CKD involves the interplay of various factors such as erythropoietin (EPO) deficiency, iron dysregulation, chronic inflammation, bone marrow dysfunction, and nutritional deficiencies. Despite recent advances in understanding this condition, anemia still remains a serious clinical challenge in population of patients with CKD. Several guidelines have been published with the aim to systematize the diagnostic approach and treatment of anemia; however, due to emerging data, many recommendations vary between publications. Recent studies indicate a potential of novel biomarkers to evaluate anemia and related conditions such as iron deficiency, which is often present in CKD patients. Our article aims to summarize the pathophysiology of anemia in CKD, as well as the diagnosis and management of this condition, including novel therapeutic approaches such as hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHI). Understanding these complex subjects is crucial for a targeted approach to diagnose and treat patients with anemia in CKD effectively.

Risk factors and current state of therapy for anemia after kidney transplantation

Post-transplant anemia is one of the most common complications in kidney transplant recipients, severely affecting patient prognosis and quality of life, and is an independent predictor of graft kidney loss and patient mortality. However, our clinical understanding and the attention given to post-transplant anemia are currently insufficient. This paper reviews the current status, risk factors, and therapeutic progress in anemia after transplantation in kidney transplant recipients. We recommend that clinical staff pay attention to anemia and its complications in kidney transplant recipients and intervene early for anemia.

Clinical features of anemia in membranous nephropathy patients: a Chinese cohort study

BACKGROUND

Anemia is a common complication in patients with progressive chronic kidney disease. This cohort study evaluated the prevalence, clinical features and prognosis of membranous nephropathy (MN) with anemia.

METHODS

We retrospectively analyzed a cohort of MN patients diagnosed using renal biopsy between February 2012 and February 2018. The clinical and pathological characteristics at baseline were recorded, and the outcomes (hemoglobin, proteinuria and renal function) during follow-ups were also evaluated. Univariate and multivariate logistic regression analyses were performed to identify the independent risk factors for anemia in MN patients. The MN patients were divided according to the therapeutic effect they experienced as follows: without-anemia, completely corrected anemia, standard anemia treatment and nonstandard anemia treatment groups. We compared the rate of complete remission of MN and renal end-point events among the four groups.

RESULTS

The median age of 483 patients was 42.43 (26.59, 50.20) years at the time of MN diagnosis. The prevalence of anemia at baseline was 23.81%, and the cumulative prevalence was 50.72%. There were 133 cases of mild anemia, 103 cases of moderate anemia and 9 cases of severe anemia; in addition, there were 228 cases of normocytic anemia and 17 cases of microcytic hypochromic anemia. Multivariate logistic regression indicated that acute renal tubule injury >5% (OR = 1.634, 95% CI 1.034, 2.581; p = 0.035), total protein level (OR = 0.949, 95% CI 0.923, 0.975; p < 0.001), cholesterol level (OR = 0.833, 95% CI 0.749, 0.926, p = 0.001), hypokalemia (OR = 2.612, 95% CI 1.227, 5.560, p = 0.013) and hypophosphatemia (OR = 2.653, 95% CI 1.303, 5.403, p = 0.007) were independent risk factors for anemia in MN patients. The complete remission rate of MN patients without anemia was significantly higher than that of anemia patients who exhibited treatment failure. The incidence of renal endpoint events was different among the four groups.

CONCLUSION

The anemia experienced by MN patients is mainly mild and moderate, normocytic anemia. The pathological features of acute renal tubular injury and clinical nutritional status are independent risk factors for anemia. There were differences in renal prognosis among anemia patients with different treatment outcomes.

Biomarkers of the End-Stage Renal Disease Progression: Beyond the GFR

Chronic kidney disease can progress to the end-stage renal disease (ESRD) characterized by a high risk of morbidity and mortality. ESRD requires immediate therapy or even dialysis or kidney transplantation, therefore, its timely diagnostics is critical for many patients. ESRD is associated with pathological changes, such as inflammation, fibrosis, endocrine disorders, and epigenetic changes in various cells, which could serve as ESRD markers. The review summarizes information on conventional and new ESRD biomarkers that can be assessed in kidney tissue, blood, and urine. Some biomarkers are specific to a particular pathology, while others are more universal. Here, we suggest several universal inflammatory, fibrotic, hormonal, and epigenetic markers indicative of severe deterioration of renal function and ESRD progression for improvement of ESRD diagnostics.

The association of hepcidin, reticulocyte hemoglobin equivalent and anemia-related indicators on anemia in chronic kidney disease

Hepcidin is an essential regulator of iron homeostasis in chronic kidney disease (CKD) anemia, reticulocyte hemoglobin equivalent (RET-He) can be used to evaluate the availability of iron for erythropoiesis. Previous research has found that hepcidin indirectly regulates RET-He. This study aimed to investigate the association of hepcidin, RET-He and anemia-related indicators on anemia in chronic kidney disease. A total of 230 individuals were recruited, including 40 CKD3-4 patients, 70 CKD5 patients without renal replacement therapy, 50 peritoneal dialysis patients, and 70 hemodialysis patients. The serum levels of hemoglobin (Hb), reticulocyte, RET-He, serum iron, serum creatinine, serum ferritin, total iron binding capacity, hepcidin-25, high sensitivity C-reactive protein, transferrin, erythropoietin, intrinsic factor antibody, soluble transferrin receptor and interleukins-6 (IL-6) were measured. Hepcidin-25 was positively associated with IL-6, and negatively with total iron binding capacity, intrinsic factor antibody, and transferrin. Reticulocyte Hb equivalent was associated positively with Hb, serum ferritin, serum iron, transferrin saturation, and negatively with serum creatinine, reticulocyte, IL-6, STfR. Hepcidin-25 was not associated with RET-He, while IL-6 was independently associated with hepcidin-25 and RET-He, suggesting that hepcidin has no effffect on the iron dynamics of reticulocytes in CKD, may be related to IL-6, indicate a likelihood of a threshold for stimulation of hepcidin-25 expression by IL-6 in order to indirectly regulates RET-He.

The association of apolipoprotein B with chronic kidney disease in the Chinese population

Background

Whether serum apolipoprotein B (ApoB) is a risk factor for the development of Chronic kidney disease (CKD) has not been fully established in the general population. Therefore, our study evaluated the correlation between serum ApoB level and CKD to look for an alternative approach for CKD prevention and treatment in the general population.

Methods

There were 146,533 participants in this cross-sectional study. 3,325 participants with more than 2 measurements were enrolled in the retrospective longitudinal study with at least a 3-year follow-up. ApoB was measured by the immunoturbidimetric method in 6 centers. Our study defined CKD as an estimated glomerular filtration rate (eGFR) < 90 mL/min/1.73 m². The Spearman rank correlation analysis and the Random Forest algorithm were applied to rank the importance of variables determining the levels of eGFR. We used the logistic regression model to explain the correlation between serum ApoB and CKD. We used the Cox model to detect the correlation between baseline serum ApoB and the subsequent occurrence of CKD.

Results

Based on a cross-sectional study, 66.5% of the participants were males, with a median age of 49 (interquartile range [IQR] 43-55). Compared to the non-CKD group, the CKD group has higher levels of lipid profile and fasting glucose as well as the proportion of hypertension and hyperuricemia. The Spearman rank correlation analysis and the Random Forest algorithm revealed that ApoB has the highest correlation with eGFR decline among lipid profiles. The logistic regression analysis revealed that ApoB had a positive correlation with the prevalence of CKD after fully controlling confounders (odds ratio [OR], 1.07; 95% confidence interval [CI]: 1.02-1.11). Moreover, baseline ApoB level was correlated with a new-onset CKD in the longitudinal cohort after full adjustment for confounding factors (hazard ratio [HR], 1.61; 95% CI: 1.02-2.54). The correlation between ApoB level and the new-onset CKD was consistently observed in all sensitivity analyses.

Conclusion

Serum ApoB had the strongest correlation with CKD among all lipid variables. Moreover, high serum ApoB levels might precede the occurrence of CKD, suggesting that monitoring and reducing serum ApoB levels may provide an alternative method to prevent and treat CKD.

Magnitude of anemia and associated factors among adult patients at Baso Liben District: a cross-sectional study

BACKGROUND

Despite the fact that anemia is a common health problem with many consequences, its magnitude among adults and the different contributing factors have not been documented in the study setting. Hence, this study aimed to determine the magnitude of anemia and associated factors among adult patients of Baso Liben District.

METHODS

A facility-based cross-sectional study was conducted from 1 December 2019, to February 30, 2020. A total of 347 adult patients attending Yejubie Hospital were enrolled in the study. Socio-demographic data were collected through face-to-face interview. Patients' hemoglobin level was determined by a Mindray BC-5800 CBC hematology analyzer. The presence of intestinal parasites and malaria infection were assessed.

RESULTS

The overall magnitude of anemia was 25.94% with moderate severity according to the WHO anemia classification. The prevalence of mild, moderate, and severe anemia was 13.54%, 8.36%, and 4.03%, respectively. Anemia was associated with age range ≥55 years (AOR = 31.66), large family size (AOR = 6.62), being married (AOR = 0.24), intestinal parasite infections (AOR = 4.05), malaria infection (AOR = 4.61), and pregnancy (AOR = 4.09).

CONCLUSION

The prevalence of anemia was moderate. Intestinal parasitic infection, age, malaria, family size, and pregnancy were associated factors with anemia.

Efficacy and safety of recombinant human erythropoietin (Hema-Plus®) for management of anemia in Thai patients on peritoneal dialysis

BACKGROUND

Hema-Plus, a recombinant human erythropoietin (rHuEPO) or epoetin alfa has shown effectiveness in correction of anemia in Thai population in clinical practice. This study was aimed to demonstrate efficacy and safety under the evidence-based approach.

AIM

To evaluate the efficacy and safety of rHuEPO (Hema-Plus) for treatment of anemia over 12 wk in Thai patients with Stage V chronic kidney disease (CKD) on peritoneal dialysis (PD).

METHODS

This study was an open-label, multi-center study to enroll 30 CKD patients identified to start PD with hemoglobin (Hb) less than 9.5 g/dL, serum ferritin more than 100 ng/mL, serum transferrin saturation more than or equal to 20% and who had not previously received epoetin. Patients with conditions that could increase the risk of adverse effects from study participation or interfere with study outcomes, were using concomitant androgens or had secondary hyperparathyroidism were excluded. All eligible patients started Hema-Plus by SC injection at 4000 IU once or twice weekly (week 0) and with follow-up at weeks 2, 4, 8, and 12. Dosage adjustment could be done to achieve Hb level of 11-12 g/dL. Primary end point was mean change in Hb level from baseline to end of treatment (week 12). Safety was assessed throughout the study. Quality of life (QoL) was assessed using KDQOL-36.

RESULTS

All 30 enrolled patients completed the study. Mean (standard deviation) Hb at baseline (week 0) to the end of 12 wk was significantly increased from 7.39 (1.29) g/dL to 11.15 (1.73) g/dL (paired t-test, P value < 0.001). Overall change of Hb means from baseline over the other 4 visits was statistically significantly increased (repeated measure ANOVA, P value < 0.001). Ten out of 39 adverse events (AEs) were serious. Two serious AEs were probably related to study medication by investigators’ assessment. At week 12, the QoL scores in all domains were significantly increased from baseline.

CONCLUSION

Hema-Plus administered for 12 wk for treatment of anemia in patients on PD effectively increased Hb levels with acceptable safety profile.

Crosstalk of fibroblast growth factor 23 and anemia-related factors during the development and progression of CKD (Review)

Fibroblast growth factor 23 (FGF23) plays an important role in the development of chronic kidney disease-mineral bone disorder (CKD-MBD). Abnormally elevated levels of 1,25-dihydroxyvitamin D cause osteocytes to secrete FGF23, which subsequently induces phosphaturia. Recent studies have reported that iron deficiency, erythropoietin (EPO) and hypoxia regulate the pathways responsible for FGF23 production. However, the molecular mechanisms underlying the interactions between FGF23 and anemia-related factors are not yet fully understood. The present review discusses the associations between FGF23, iron, EPO and hypoxia-inducible factors (HIFs), and their impact on FGF23 bioactivity, focusing on recent studies. Collectively, these findings propose interactions between FGF23 gene expression and anemia-related factors, including iron deficiency, EPO and HIFs. Taken together, these results suggest that FGF23 bioactivity is closely associated with the occurrence of CKD-related anemia and CKD-MBD.

Efficacy of roxadustat in treatment of peritoneal dialysis patients with renal anaemia

BACKGROUND

There are no studies on the use of roxadustat in patients on regular peritoneal dialysis in China.

AIM

To observe the efficacy and safety of roxadustat in treating renal anaemia in peritoneal dialysis patients.

METHODS

Patients with renal anaemia who were regularly followed at the Peritoneal Dialysis Center of the First Affiliated Hospital of China Medical University from November 1, 2019 to June 30, 2020 were selected. A before-and-after self-control design was performed to retrospectively analyse the treatment effects on anaemia in patients treated with recombinant human erythropoietin (EPO) and roxadustat.

RESULTS

A total of 31 patients with renal anaemia on long-term peritoneal dialysis treated with roxadustat were included. Haemoglobin (Hb) levels were maintained or increased in all patients (100%), and no patients had a decrease in Hb compared with the previous phase. Patients had a mean Hb of 86.2 ± 14.8 g/L with Hb compliance (Hb ≥ 110 g/L) of 16.1% during the EPO phase and a mean Hb of 112.4 ± 18.5 g/L with Hb compliance of 67.7% during the roxadustat phase. No major adverse cardiovascular events occurred in any patient.

CONCLUSION

The application of roxadustat in peritoneal dialysis patients with renal anaemia can effectively improve the Hb compliance rate.

Pre-Frailty and Frailty in Dialysis and Pre-Dialysis Patients: A Systematic Review of Clinical and Biochemical Markers

Patients under dialysis are known to be more vulnerable to frailty, a dynamic geriatric syndrome defined as a state of vulnerability to stressors, due to numerous metabolic changes. With rise of life expectancy globally, it is important to understand the complexity of the pathophysiology of frailty and identify possible markers that can help with the prognosis and diagnosis of frailty. The aim of this systematic review is to give an overview of the knowledge regarding clinical and biochemical markers associated with pre-frailty and frailty in dialysis and pre-dialysis patients. In November 2020, PubMed, Embase and Web of Science were searched. Studies regarding biomarkers associated with (pre-)frailty in (pre-)dialysis patients were included. This systematic review identified clinical and biochemical markers in pre-frail and frail patients under dialysis or pre-dialysis published in the literature. This study shows that more investigation is necessary to identify markers that can differentiate these processes to be used as a diagnostic and prognostic tool in routine care and management of geriatric needs. Interventions that can improve health outcomes in pre-frail and frail older adults under dialysis or pre-dialysis are essential to improve not only the individual's quality of life but also to reduce the burden to the health systems.

The Impact of Intravenous Iron Supplementation on Hematinic Parameters and Erythropoietin Requirements in Hemodialysis Patients

INTRODUCTION

Anemia is one of the most common complications of chronic kidney disease (CKD). As a result of the side effects of high doses of recombinant human erythropoietin (rhEPO) and the differences in the standard dose of the injectable iron, this study aimed to evaluate the effect of high and low intravenous iron supplementation on hematinic parameters and EPO requirements in patients under hemodialysis.

METHODS

This multicenter, randomized, double-blind clinical trial was conducted on 60 patients with CKD admitted to Sina and 29 Bahman hospitals in Tabriz, Iran in 2019-2020 to undergo hemodialysis. In the two studied groups, low (100 mg/week) and high (400 mg/week) doses of iron were administered and subjects were followed up for 6 months. The incidence of acute myocardial ischemia, stroke, and mortality during 6 months was recorded.

RESULTS

The required rhEPO dosage (mg/week) to maintain hemoglobin levels between 10 and 12 g/dL in the high-dose iron group was significantly decreased during the follow-up period (52,129.03 ± 23,810 vs. 45,760 ± 20,978.71, P ≤ 0.028). Transferrin saturation (TSAT) index had a significant upward trend after iron injection and significant correlations with the serum levels of Fe (r ≥ 0.353, P ≤ 0.007), ferritin (r ≥ 0.315, P ≤ 0.016), and total iron binding capacity (r ≥ 0.219, P < 0.050) during the follow-up period in the studied groups.

CONCLUSION

High-dose intravenous iron (400 mg/week) can reduce the mean dose of rhEPO requirements and increase the TSAT index over a period of 6 months in hemodialysis patients. High-dose IV iron administration can decrease cardiovascular events in hemodialysis patients with iron deficiency anemia.

Roxadustat treatment for anemia in peritoneal dialysis patients: A randomized controlled trial

BACKGROUND/PURPOSE

Roxadustat, a first-in-class hypoxia-inducible factor prolyl hydroxylase inhibitor, promotes erythropoiesis and regulates iron metabolism. This study investigated the efficacy and safety of roxadustat in Chinese patients with anemia on peritoneal dialysis (PD).

METHODS

One hundred and twenty-nine patients were randomized and treated with roxadustat (n = 86) or erythropoiesis-stimulating agents (ESAs) (n = 43) for 24 weeks. The primary end points were the mean hemoglobin (Hb) level at week 24, the change in average Hb levels from baseline to week 24, and the cumulative response rate throughout the treatment period. The secondary end points included changes in hepcidin and iron indices and serum lipid levels. Subgroup analysis examined the effect of inflammatory status on the efficacy of Hb. Safety was assessed as the occurrence of emergent adverse events after treatment.

RESULTS

The mean average Hb levels at week 24 and average change in Hb levels from baseline to week 24 were 11.5 g/dL and 2.5 g/dL in the roxadustat group and 11.2 g/dL and 2.2 g/dL in the ESAs group, respectively. The cumulative response rate was 96% in the roxadustat group and 92% in the ESAs group at week 24. Roxadustat decreased hepcidin levels and increased total iron-binding capacity. The decreases in total cholesterol and low-density lipoprotein cholesterol were greater with roxadustat than with ESAs. Roxadustat-induced Hb increases were independent of baseline C-reactive protein levels. Common adverse events included hyperkalemia, hypertension, and insomnia.

CONCLUSION

Roxadustat effectively corrected and maintained target Hb levels in Chinese PD patients. This trial was registered in the Chinese Clinical Trial Register (ChiCTR2000035054).

Anaemia and iron deficiency in patients with rheumatoid arthritis and other chronic diseases

Anaemia is one of the most common symptoms accompanying many chronic diseases, e.g. collagenases, neoplasms, and chronic inflammations (inflammatory bowel disease, chronic kidney disease and heart failure). Iron deficiency anaemia is the most common type of anaemia (80%). It affects 1% to 2% of the population. Iron deficiency (ID) – absolute or functional – is characterised by reduced ferritin levels and transferrin saturation (TSAT) of less than 20%. Iron deficiency is the most common dietary deficiency. However, iron deficiency might be one of the common causes of anaemia of chronic disease (ACD). Anaemia affects 33% to 60% of patients with RA. Rheumatoid arthritis (RA) is a chronic immune-mediated systemic connective tissue disease, in which chronic inflammation of the synovial tissue of the joints damages articular cartilages, bones and other joint structures. The prevalence of RA is approximately 0.3% to 2%. Low haemoglobin levels in RA patients are significantly correlated with disability, activity and duration of the disease as well as damage to joints and joint pain. Treatment of anaemia in RA patients includes iron supplementation, blood transfusions, the use of erythropoiesis-stimulating agents, and treatment of the underlying condition. Biological treatments used in RA patients, such as e.g. infliximab, tocilizumab and anakinra, not only slow the progression of joint involvement but also prevent anaemia.

The Interplay Between Nutrition, Metabolic, and Endocrine Disorders in Chronic Kidney Disease

The kidneys are responsible for maintaining our bodies' homeostasis through excretion, biodegradation, and synthesis of different hormones. Therefore, a decline in renal function often results in significant derangements in hormone levels. The most common metabolic and endocrine abnormalities seen in patients with chronic kidney disease include deficiencies in erythropoietin, calcitriol, triiodothyronine, testosterone, and estrogen. In addition, accumulation of hormones such as adiponectin, leptin, triglycerides, and prolactin also is seen. Subsequently, this can lead to the development of a wide range of clinical consequences including but not limited to anemia, hyperparathyroidism, insulin resistance, anorexia-cachexia, infertility, bone disorders, and cardiovascular diseases. These disorders can negatively affect the prognosis and quality of life of patients with chronic kidney disease, and, thus, early diagnosis, nutritional intervention, and pharmacologic treatment is imperative.

Relationship between serum hepcidin levels and cardiovascular disease in patients with maintenance hemodialysis

Background

To investigate the serum level of hepcidin and its relationship with cardiovascular disease (CVD) in maintenance hemodialysis (MHD) patients.

Methods

Blood was obtained from 75 MHD patients before undergoing hemodialysis and 20 healthy controls. Serum hepcidin, advanced oxidation protein products (AOPP) and interleukin (IL)-6 were measured by enzyme-linked immunosorbant assay (ELISA). Spearman correlation, and binary logistic regression linear regression analyses were used to assess the relationship between serum hepcidin and other parameters.

Results

The serum level of hepcidin, AOPP and IL-6 was significantly up-regulated in MHD patients compared with the control (P < 0.05). Furthermore, serum hepcidin levels in patients with CVD were higher than those in patients without CVD (P < 0.05). In all MHD patients, serum hepcidin level was correlated positively with erythropoietin (EPO) dose per week (ρ = 0.251, P = 0.030), EPO resistance index (ρ = 0.268, P = 0.020), ferritin (ρ = 0.814, P < 0.001), transferin saturation (TSAT, ρ = 0.263, P = 0.023), AOPP (ρ = 0.280, P = 0.049), high sensitive C reactive protein (ρ = 0.151, P = 0.006), IL-6 (ρ = 0.340, P = 0.003) and left ventricular mass index (LVMI, ρ = 0.290, P = 0.033). Moreover, it was negatively correlated with serum pre-albumin (ρ = -0.266, P = 0.021), total iron-binding capacity (TIBC, ρ = -0.458, P < 0.001), unsaturated iron-binding capacity (UIBC, ρ = -0.473, P < 0.001) and transferrin (ρ = -0.487, P < 0.001). Linear regression analysis showed that ferritin (β = 0.708, P < 0.001), TIBC (β = -0.246, P = 0.032) and IL-6 (β = 0.209, P = 0.041) were independently associated with hepcidin. Results of binary logistic regression analysis suggested that higher serum hepcidin level (>249.2 ng/mL) was positively and independently related to CVD (OR = 1.32, 95% CI [1.20-9.56], P = 0.043).

Conclusions

Serum hepcidin level is associated with CVD in MHD patients, indicating that hepcidin may be a novel biomarker and therapeutic target for CVD.

Clinical and genetic markers of erythropoietin deficiency anemia in chronic kidney disease (predialysis) patients

Aim: To determine the clinical and genetic markers associated with erythropoietin deficiency anemia in predialysis individuals. Materials & methods: Patients were categorized into cases and control group. Demographic characteristics and clinical parameters were obtained from medical record review and serum EPO and ferritin were obtained with ELISA. HIF-1α (rs2057482), IL-1β (rs1143627) and EPO (rs1617640) gene polymorphism were genotyped. Results: Female gender, glomerular filtration rate, treatment with hematinics, anticoagulant and diuretic were strong predictors of EPO-deficient anemia in predialysis chronic kidney disease patients. Genetic polymorphism in the HIF-1α recessive model was associated with non-EPO-deficiency, followed by EPO recessive allele associated with low-serum erythropoietin and IL-1β recessive model with low hemoglobin level. Conclusion: EPO-deficiency anemia can be diagnosed more conveniently in the presence of biomarkers.

Freestanding Dialysis Facility Quality Incentive Program Scores and Mortality Among Incident Dialysis Patients in the United States

RATIONALE & OBJECTIVE

The Centers for Medicare & Medicaid Services introduced the Quality Incentive Program (QIP) along with the bundled payment reform to improve the quality of dialysis care in the United States. The QIP has been criticized for using easily obtained laboratory indicators without patient-centered measures and for a lack of evidence for an association between QIP indicators and patient outcomes. This study examined the association between dialysis facility QIP performance scores and survival among patients after initiation of dialysis.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Study participants included 84,493 patients represented in the US Renal Disease System's patient-level data who had initiated dialysis between January 1, 2013, and December 1, 2013, and who did not, during the first 90 days after dialysis initiation, die, receive a transplant, or become lost to follow-up. Patients were followed up for the study outcome through March 31, 2014.

PREDICTOR

Dialysis facility QIP scores.

OUTCOME

Mortality.

ANALYTICAL APPROACH

Using a unique facility identifier, we linked Medicare freestanding dialysis facility data from 2015 with US Renal Disease System patient-level data. Kaplan-Meier product limit estimator was used to describe the survival of study participants. Cox proportional hazards regression was used to assess the multivariable association between facility performance scores and patient survival.

RESULTS

Excluding patients who died during the first 90 days of dialysis, 11.8% of patients died during an average follow-up of 5 months. Facilities with QIP scores<45 (HR, 1.39; 95% CI, 1.15-1.68) and 45 to<60 (HR, 1.21; 95% CI, 1.10-1.33) had higher patient mortality rates than facilities with scores≥90.

LIMITATIONS

Because the Centers for Medicare & Medicaid Services have revised QIP criteria each year, the findings may not relate to years other than those studied.

CONCLUSIONS

Dialysis facilities characterized by lower QIP scores were associated with higher rates of patient mortality. These findings need to be replicated to assess their consistency over time.

Comparing the effects of intravenous and subcutaneous Erythropoietin on blood indices in hemodialysis patients

Erythropoietin is used routinely in hemodialysis patients to increase hemoglobin levels in patients with ESRD and anemia. Considering the importance of anemia in hemodialysis patients and its complications, in this study, the effect of erythropoietin administration on blood parameters by comparing the methods of subcutaneous and intravenous administrations was investigated. The research was done as a retrospective descriptive-analytic study. The subjects were 300 hemodialysis patients receiving erythropoietin in two groups (intravenous and subcutaneous) from hospitals affiliated to Kurdistan and Kermanshah University of Medical Sciences. Data were extracted from the patients' records and entered into a researcher-made checklist during 6 months and analyzed using SPSS version 20 and descriptive and inferential statistics. The results showed that there was a significant difference between the mean rank of hematocrit in subcutaneous and intravenous injections (P-value = 0.002) and it was higher in the subcutaneous injection group. Also, independent t-test showed that there was a significant difference between the mean of hemoglobin concentration among subcutaneous and intravenous injections (P-value = 0.001) and it was higher in the subcutaneous injection group. However, there was no significant difference between the mean of ferritin in both groups (P-value = 0.084). According to the results, the injection of erythropoietin in the subcutaneous method was more effective than intravenous. It is recommended to use this approach to improve blood indices in hemodialysis patients.

Hepcidin in chronic kidney disease anemia

Chronic kidney disease (CKD) is associated with several complications that worsen with progression of disease; anemia, disturbances in iron metabolism and inflammation are common features. Inflammatory response starts early, releasing pro-inflammatory cytokines, acute phase reactants and hepcidin. Hepcidin production is modulated by several factors, as hypoxia/anemia, erythropoietin and erythropoiesis products, transferrin saturation (TSAT) and liver iron levels, which are altered in CKD. Treatment of CKD anemia is based on pharmaceutical intervention, with erythropoietic stimulating agents and/or iron supplementation; however, in spite of the erythropoietic benefits, this therapy, on a regular basis, involves risks, namely iron overload. To overcome these risks, some therapeutic approaches are under study to target CKD anemia. Considering the actual alerts about risk of iron overload in dialysis patients, inhibition of hepcidin, the central key player in iron homeostasis, could be a pivotal strategy in the management of CKD anemia.

Regulation of Fibroblast Growth Factor 23 by Iron, EPO, and HIF

Purpose of review

Fibroblast growth factor-23 (FGF23) is the key hormone produced in bone critical for phosphate homeostasis. Elevated serum phosphorus and 1,25dihydroxyvitaminD stimulates FGF23 production to promote renal phosphate excretion and decrease 1,25dihydroxyvitaminD synthesis. Thus completing the feedback loop and suppressing FGF23. Unexpectedly, studies of common and rare heritable disorders of phosphate handling identified links between iron and FGF23 demonstrating novel regulation outside the phosphate pathway.

Recent Findings

Iron deficiency combined with an FGF23 cleavage mutation was found to induce the autosomal dominant hypophosphatemic rickets phenotype. Physiological responses to iron deficiency, such as erythropoietin production as well as hypoxia inducible factor activation, have been indicated in regulating FGF23. Additionally, specific iron formulations, used to treat iron deficiency, alter post-translational processing thereby shifting FGF23 protein secretion.

Summary

Molecular and clinical studies revealed that iron deficiency, through several mechanisms, alters FGF23 at the transcriptional and post-translational level. This review will focus upon the novel discoveries elucidated between iron, its regulators, and their influence on FGF23 bioactivity.

Design, synthesis, and activity evaluation of novel erythropoietin mimetic peptides

The approval of the erythropoietin (EPO) mimetic peptide drug peginesatide in 2012 was a breakthrough for the treatment of secondary anemia. However, due to severe allergic reactions, peginesatide was recalled a year later. In this study, 12 novel peptides were designed and synthesized by substituting specific amino acids of the monomeric peptide in peginesatide, with the aim of obtaining new EPO mimetic peptides with higher activities and lower side effects than the parent compound. Their cell proliferation activities were evaluated, and the structure-activity relationships were analyzed. Five compounds had equal cell proliferation activity to the control peptide. Among them, one compound showed a higher in vivo activity than the control peptide, with no obvious side effects.

Artificial Intelligence for the Artificial Kidney: Pointers to the Future of a Personalized Hemodialysis Therapy

Background

Current dialysis devices are not able to react when unexpected changes occur during dialysis treatment or to learn about experience for therapy personalization. Furthermore, great efforts are dedicated to develop miniaturized artificial kidneys to achieve a continuous and personalized dialysis therapy, in order to improve the patient's quality of life. These innovative dialysis devices will require a real-time monitoring of equipment alarms, dialysis parameters, and patient-related data to ensure patient safety and to allow instantaneous changes of the dialysis prescription for the assessment of their adequacy. The analysis and evaluation of the resulting large-scale data sets enters the realm of "big data" and will require real-time predictive models. These may come from the fields of machine learning and computational intelligence, both included in artificial intelligence, a branch of engineering involved with the creation of devices that simulate intelligent behavior. The incorporation of artificial intelligence should provide a fully new approach to data analysis, enabling future advances in personalized dialysis therapies. With the purpose to learn about the present and potential future impact on medicine from experts in artificial intelligence and machine learning, a scientific meeting was organized in the Hospital Universitari Bellvitge (L'Hospitalet, Barcelona). As an outcome of that meeting, the aim of this review is to investigate artificial intel ligence experiences on dialysis, with a focus on potential barriers, challenges, and prospects for future applications of these technologies.

Summary and Key Messages

Artificial intelligence research on dialysis is still in an early stage, and the main challenge relies on interpretability and/or comprehensibility of data models when applied to decision making. Artificial neural networks and medical decision support systems have been used to make predictions about anemia, total body water, or intradialysis hypotension and are promising approaches for the prescription and monitoring of hemodialysis therapy. Current dialysis machines are continuously improving due to innovative technological developments, but patient safety is still a key challenge. Real-time monitoring systems, coupled with automatic instantaneous biofeedback, will allow changing dialysis prescriptions continuously. The integration of vital sign monitoring with dialysis parameters will produce large data sets that will require the use of data analysis techniques, possibly from the area of machine learning, in order to make better decisions and increase the safety of patients.

Efficacy and safety of subcutaneous administration of lyophilized powder of alfa-erythropoietin to maintain hemoglobin concentrations among hemodialysis patients

Background

Anemia associated with chronic kidney disease (CKD) often requires treatment with recombinant human erythropoietin (EPO). This study investigated the therapeutic equivalence between lyophilized powder and standard liquid EPO alfa by subcutaneous (SC) administration in hemoglobin maintenance among patients on hemodialysis.

Methods

This was a single-blinded, randomized, controlled, single-center, parallel-group study regarding the treatment of anemia among CKD patients on hemodialysis and being treated with stable doses of EPO alfa at least for 12 weeks. Anemic hemodialysis patients (n=63) received standard liquid or lyophilized powder EPO alfa for 24 weeks by SC administration. Achievement of the target hemoglobin concentration and safety and tolerability end points were documented.

Results

Baseline mean hemoglobin level was 11.1±0.7 g/dL using lyophilized powder EPO alfa and 11.2±0.9 g/dL using standard liquid EPO alfa. The baseline median dose of EPO alfa was 126.4 (interquartile range [IQR] 81.6–163.6) U/kg/week in the lyophilized powder EPO alfa group and 116.9 (IQR 76.5–144.1) U/kg/week in the standard liquid EPO alfa group. Treatment with SC lyophilized powder EPO alfa maintained mean hemoglobin and hematocrit concentrations after switching from standard liquid EPO alfa. No statistical significance between groups was reported for hemoglobin concentrations and weekly dose of EPO alfa during the study. No safety concerns were raised, including positive anti-EPO antibodies.

Conclusion

In this study of anemia therapy among patients with end-stage renal disease on hemodialysis therapy, the SC injection of lyophilized powder EPO alfa was well tolerated and effectively maintained hemoglobin levels. Future studies of larger size and longer duration will be required to assess safety profiles.

V-J combinations of T-cell receptor predict responses to erythropoietin in end-stage renal disease patients

Background

Anemia is common among end-stage renal disease (ESRD) patients who undergone hemodialysis. The total reduction of red blood cell (RBC) count is associated with poor prognosis in these patients. Although erythropoietin (EPO) has been used as an effective treatment for ESRD patients with anemia, a large number of patients still present poor responses to EPO treatment.

Methods

We measured T-cell receptor sequencing profiles, including length of complementarity-deteremining region 3 (CDR3), intra- and inter-group (EPO resistant vs. responsive) clonotype diversity, V(D)J usage profiles and V-J combinations from ESRD patients and to investigate the correlation between these features and EPO treatment efficacy.

Results

Our results revealed statistical significance in the top 3 ~ 15 most abundant joint distributions of Vβ/Jβ among the two groups, suggesting the importance of V or J gene utilization in the EPO response of ESRD patients.

Conclusions

In summary, we provided evidence addressing the potential correlation between the immune repertoire and EPO response in ESRD patients.

Trial registration

TMU-JIRB 201309026. Registered 16 October 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s12929-017-0349-5) contains supplementary material, which is available to authorized users.

Erythropoietin: Endogenous Protection of Ischemic Brain

The human brain requires uninterrupted delivery of blood-borne oxygen and nutrients to sustain its function. Focal ischemia, particularly, ischemic stroke, and global ischemia imposed by cardiac arrest disrupt the brain's fuel supply. The resultant ATP depletion initiates a complex injury cascade encompassing intracellular Ca²⁺ overload, glutamate excitotoxicity, oxido-nitrosative stress, extracellular matrix degradation, and inflammation, culminating in neuronal and astroglial necrosis and apoptosis, neurocognitive deficits, and even death. Unfortunately, brain ischemia has proven refractory to pharmacological intervention. Many promising treatments afforded brain protection in animal models of focal and global ischemia, but failed to improve survival and neurocognitive recovery of stroke and cardiac arrest patients in randomized clinical trials. The culprits are the blood-brain barrier (BBB) that limits transferral of medications to the brain parenchyma, and the sheer complexity of the injury cascade, which presents a daunting array of targets unlikely to respond to monotherapies. Erythropoietin is a powerful neuroprotectant capable of interrupting multiple aspects of the brain injury cascade. Preclinical research demonstrates erythropoietin's ability to suppress glutamate excitotoxicity and intracellular Ca²⁺ overload, dampen oxidative stress and inflammation, interrupt the apoptotic cascade, and preserve BBB integrity. However, the erythropoietin dosages required to traverse the BBB and achieve therapeutically effective concentrations in the brain parenchyma impose untoward side effects. Recent discoveries that hypoxia induces erythropoietin production within the brain and that neurons, astroglia, and cerebrovascular endothelium harbor membrane erythropoietin receptors, raise the exciting prospect of harnessing endogenous erythropoietin to protect the brain from the ravages of ischemia-reperfusion.

Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitors: A Potential New Treatment for Anemia in Patients With CKD

Erythropoiesis-stimulating agents (ESAs) increase hemoglobin levels, reduce transfusion requirements, and have been the standard of treatment for anemia in patients with chronic kidney disease (CKD) since 1989. Many safety concerns have emerged regarding the use of ESAs, including an increased occurrence of cardiovascular events and vascular access thrombosis. Hypoxia-inducible factor (HIF) prolyl hydroxylase (PH) enzyme inhibitors are a new class of agents for the treatment of anemia in CKD. These agents work by stabilizing the HIF complex and stimulating endogenous erythropoietin production even in patients with end-stage kidney disease. HIF-PH inhibitors improve iron mobilization to the bone marrow. They are administered orally, which may be a more favorable route for patients not undergoing hemodialysis. By inducing considerably lower but more consistent blood erythropoietin levels than ESAs, HIF-PH inhibitors may be associated with fewer adverse cardiovascular effects at comparable hemoglobin levels, although this has yet to be proved in long-term clinical trials. One significant concern regarding the long-term use of these agents is their possible effect on tumor growth. There are 4 such agents undergoing phase 2 and 3 clinical trials in the United States; this report provides a focused review of HIF-PH inhibitors and their potential clinical utility in the management of anemia of CKD.

Frequency of Specific Cardiovascular Disease Risk Factors among Cameroonian Patients on Dialysis: The Cases of Anaemia, Inflammation, Phosphate, and Calcium

Specific cardiovascular risk factors are known to contribute to increasing cardiovascular mortality in patients with chronic renal disease. However, little is known about their distribution in our population. This study aimed at determining the prevalence of anaemia, inflammation, and phosphocalcium disorders in Cameroonian patients on dialysis. Thirty-five participants with stage V chronic kidney disease (defined by glomerular filtration rate, GFR < 15 mL/1.73 m(3)) of age at least 20 years on haemodialysis were randomly recruited. A control group composed of persons without a history of renal or cardiovascular disease was also recruited. Haemoglobin concentration, serum phosphate concentration, serum calcium concentration, and CRP status as a marker of inflammation were determined for all participants. Anaemia, phosphocalcium metabolic disorders, and a positive CRP result among haemodialysed patients were estimated at 94.3%, 61.6%, and 77.1%, respectively. Anaemia was diagnosed in all female patients compared to 92% in males, while a positive CRP result was recorded in 90% of females and 72% of males. No significant differences were observed on the distribution of studied specific cardiovascular risk factors with duration of dialysis. Among the factors studied, anaemia was the most encountered.

Development of quality indicators for care of chronic kidney disease in the primary care setting using electronic health data: a RAND-modified Delphi method

BACKGROUND

The prevalence of chronic kidney disease (CKD) has recently increased, and maintaining high quality of CKD care is a major factor in preventing end-stage renal disease. Here, we developed novel quality indicators for CKD care based on existing electronic health data.

METHODS

We used a modified RAND appropriateness method to develop quality indicators for the care of non-dialysis CKD patients, by combining expert opinion and scientific evidence. A multidisciplinary expert panel comprising six nephrologists, two primary care physicians, one diabetes specialist, and one rheumatologist assessed the appropriateness of potential indicators extracted from evidence-based clinical guidelines, in accordance with predetermined criteria. We developed novel quality indicators through a four-step process: selection of potential indicators, first questionnaire round, face-to-face meeting, and second questionnaire round.

RESULTS

Ten expert panel members evaluated 19 potential indicators in the first questionnaire round, of which 7 were modified, 12 deleted, and 4 newly added during subsequent face-to-face meetings, giving a final total of 11 indicators. Median rate of these 11 indicators in the final set was at least 7, and percentages of agreement exceeded 80 % for all but one indicator. All indicators in the final set can be measured using only existing electronic health data, without medical record review, and 9 of 11 are process indicators.

CONCLUSION

We developed 11 quality indicators to assess quality of care for non-dialysis CKD patients. Strengths of the developed indicators are their applicability in a primary care setting, availability in daily practice, and emphasis on modifiable processes.

Associations among Erythroferrone and Biomarkers of Erythropoiesis and Iron Metabolism, and Treatment with Long-Term Erythropoiesis-Stimulating Agents in Patients on Hemodialysis

BACKGROUND

We aimed to identify associations between erythroferrone (ERFE), a regulator of hepcidin 25, and biomarkers of erythropoiesis and iron metabolism. We also aimed to determine the effects of erythropoiesis-stimulating agents (ESA), continuous erythropoietin receptor activator (CERA) and darbepoetin-α (DA) on ERFE production in patients on hemodialysis (HD).

METHODS

Blood samples were obtained from 59 patients before HD sessions on day 0 (baseline). Twenty patients who were injected with either CERA (N = 10) or DA (N = 10) at the end of the dialysis week (day 0), who had ferritin ≥ 100 ng/mL and/or transferrin saturation ≥ 20%, and hemoglobin > 9 g/dL were selected from among the 59 patients. Blood was sampled serially before HD sessions on days 3, 5, 7 from patients on DA and on the same days plus day 14 from those on CERA.

RESULTS

Levels of ERFE correlated inversely with those of hepcidin 25 and ferritin, and positively with those of soluble transferrin receptor. The hepcidin 25: ERFE ratio and hepcidin 25 levels positively correlated with ferritin levels. Levels of ERFE significantly increased from day 3 of treatment with DA and CERA and decreased by days 7 and 14, respectively. Erythropoiesis-stimulating agents concomitantly decreased levels of hepcidin 25 as those of ERFE increased.

CONCLUSION

We identified a novel association between ESA and ERFE in patients on HD. Both DA and CERA increased levels of ERFE that regulated hepcidin 25 and led to iron mobilization from body stores during erythropoiesis.

Resistance to Recombinant Human Erythropoietin Therapy in a Rat Model of Chronic Kidney Disease Associated Anemia

This study aimed to elucidate the mechanisms explaining the persistence of anemia and resistance to recombinant human erythropoietin (rHuEPO) therapy in a rat model of chronic kidney disease (CKD)-associated anemia with formation of anti-rHuEPO antibodies. The remnant kidney rat model of CKD induced by 5/6 nephrectomy was used to test a long-term (nine weeks) high dose of rHuEPO (200 UI/kg bw/week) treatment. Hematological and biochemical parameters were evaluated as well as serum and tissue (kidney, liver and/or duodenum) protein and/or gene expression of mediators of erythropoiesis, iron metabolism and tissue hypoxia, inflammation, and fibrosis. Long-term treatment with a high rHuEPO dose is associated with development of resistance to therapy as a result of antibodies formation. In this condition, serum EPO levels are not deficient and iron availability is recovered by increased duodenal absorption. However, erythropoiesis is not stimulated, and the resistance to endogenous EPO effect and to rHuEPO therapy results from the development of a hypoxic, inflammatory and fibrotic milieu in the kidney tissue. This study provides new insights that could be important to ameliorate the current therapeutic strategies used to treat patients with CKD-associated anemia, in particular those that become resistant to rHuEPO therapy.

Can Serum Gdf-15 be Associated with Functional Iron Deficiency in Hemodialysis Patients?

Functional iron deficiency (FID) incidence is gradually increasing in hemodialysis (HD) patients. Recently, high levels of GDF-15 supressed the iron regulatory protein hepcidin and GDF-15 expression increased in iron-deficient patients. The relationship between FID, GDF-15, and hepcidin is currently unknown. The present study aimed to evaluate the association between GDF-15, hepcidin, and FID in chronic HD patients. Serum GDF-15 and hepcidin concentrations were measured in 105 HD patients and 40 controls. FID is defined as serum ferritin >800 ng/mL, TSAT <25 %, Hb levels <11 g/dL, and reticulocyte haemoglobin content (CHr) <29 pg. Serum GDF-15 and hepcidin levels were increased significantly in HD patients with FID, compared to HD patients without anemia and controls. GDF-15 correlated with ferritin, hepcidin, and CRP in the entire cohort. GDF-15 was related to ferritin and CRP in HD patients with FID. GDF-15 is better diagnostic marker than hepcidin for detection of FID [AUC = 0.982 (0.013) versus AUC = 0.921 (0.027); P = 0.0324]. GDF-15 appears to be a promising tool for detection of FID. High levels of ferritin and CRP correlated with GDF-15. Our results support GDF-15 as a new mediator of FID via hepcidin, chronic inflammation, or unknown pathways.

Blood transfusion, serum ferritin, and iron in hemodialysis patients in Africa

Background and Objectives. There is no data analyzing the outcome of blood transfusions and oral iron therapy in patients with kidneys failure in sub-Saharan Africa. The present study aimed to fill that gap and assess the value of ferritin in the diagnosis of iron overload and deficiency. Design. From January to February 2012, we prospectively studied 85 hemodialysis patients (78% of males and 22% of females aged 20 to 79 years) attending the Gabonese National Hemodialysis Centre. Results. Correlation studies showed (a) a strong positive linear relationship between the number of blood transfusions and high serum ferritin in hemodialysis patient (Spearman r : 0.74; P value: 0.0001); (b) a weak association between the number of blood transfusions and serum iron concentrations (Spearman r : 0.32; P value: 0.04); (c) a weak association between serum ferritin and serum iron (Spearman r : 0.32; P value: 0.003). Also, the strength of agreement beyond chance between the levels of ferritin and iron in the serum was poor (κ = 0.14). The prevalence of iron overload was 10.6%, whereas the prevalence of iron deficiency was 2.3%, comparing (1) patients with a maximum of one transfusion not on iron therapy; (2) patients with a maximum of one transfusion on iron therapy; (3) polytransfused patients not on iron therapy; and (4) polytransfused patients on oral iron therapy. The "Kruskal-Wallis test" showed that ferritin levels varied significantly between the groups (P value: 0.0001). Conclusion. Serum ferritin is not reliable as a marker of iron overload. For patients undergoing regular transfusion we recommend routine serum ferritin measurement and yearly measurement of LIC.

Anaemia in chronic obstructive pulmonary disease: an insight into its prevalence and pathophysiology

Chronic obstructive pulmonary disease (COPD) is a major health problem, with increasing morbidity and mortality. There is a growing literature regarding the extra-pulmonary manifestations of COPD, which can have a significant impact on symptom burden and disease progression. Anaemia is one of the more recently identified co-morbidities, with a prevalence that varies between 4.9% and 38% depending on patient characteristics and the diagnostic criteria used. Systemic inflammation seems to be an important factor for its establishment and repeated bursts of inflammatory mediators during COPD exacerbations could further inhibit erythropoiesis. However, renal impairment, malnutrition, low testosterone levels, growth hormone level abnormalities, oxygen supplementation, theophylline treatment, inhibition of angiotensin-converting enzyme and aging itself are additional factors that could be associated with the development of anaemia. The present review evaluates the published literature on the prevalence and significance of anaemia in COPD. Moreover, it attempts to elucidate the reasons for the high variability reported and investigates the complex pathophysiology underlying the development of anaemia in these patients.

Effect of erythropoietin on primed leucocyte expression profile

Resistance to erythropoietin (EPO) affects a significant number of anaemic patients with end-stage renal disease. Previous reports suggest that inflammation is one of the major independent predictors of EPO resistance, and the effects of EPO treatment on inflammatory mediators are not well established. The aim of this study was to investigate EPO-induced modification to gene expression in primary cultured leucocytes. Microarray experiments were performed on primed ex vivo peripheral blood mononuclear cells (PBMCs) and treated with human EPO-α. Data suggested that EPO-α modulated genes involved in cell movement and interaction in primed PBMCs. Of note, EPO-α exerts anti-inflammatory effects inhibiting the expression of pro-inflammatory cytokine IL-8 and its receptor CXCR2; by contrast, EPO-α increases expression of genes relating to promotion of inflammation encoding for IL-1β and CCL8, and induces de novo synthesis of IL-1α, CXCL1 and CXCL5 in primed cells. The reduction in MAPK p38-α activity is involved in modulating both IL-1β and IL-8 expression. Unlike the induction of MAPK, Erk1/2 activity leads to upregulation of IL-1β, but does not affect IL-8 expression and release. Furthermore, EPO-α treatment of primed cells induces the activation of caspase-1 upstream higher secretion of IL-1β, and this process is not dependent on caspase-8 activation. In conclusion, our findings highlight new potential molecules involved in EPO resistance and confirm the anti-inflammatory role for EPO, but also suggest a plausible in vivo scenario in which the positive correlation found between EPO resistance and elevated levels of some pro-inflammatory mediators is due to treatment with EPO itself.

Human cytomegalovirus inhibits erythropoietin production

Anemia is a feature of CKD and a complication of renal transplantation, often caused by impaired production of erythropoietin. The kidney is a target organ for human cytomegalovirus (hCMV) in such patients, but it is not known whether hCMV effects erythropoietin production. We found that kidneys from patients with CKD were positive for hCMV protein and that blood levels of hCMV IgG inversely correlated with red blood cell count. In mice, systemic murine cytomegalovirus infection decreased serum erythropoietin levels. In human erythropoietin-producing cells, hCMV inhibited hypoxia-induced expression of erythropoietin mRNA and protein. hCMV early gene expression was responsible, as ultraviolet-inactivated virus had no effect and valganciclovir treatment showed that late gene expression was nonessential. Hypoxia-induced gene transcription is controlled by the transcription factors hypoxia-inducible transcription factor (HIF)-1α and HIF2α, which are constitutively produced but stable only under low oxygen conditions. We found that hCMV inhibited constitutive production of HIF2α mRNA. HIF2α is thought to be the master regulator of erythropoietin transcription. Single-cell analysis revealed that nuclear accumulation of HIF2α was inhibited in hCMV-infected cells, and the extent of inhibition correlated with hCMV protein expression. Our findings suggest that renal hCMV infection could induce or exacerbate anemia in patients.

Hematologic manifestations of kidney disease

Physiologically, there is an intimate link between the kidney and the blood. Many of the kidney diseases are the result of alteration in the blood such as dysproteinemia, microangiopathic hemolytic anemia (MAHA), hemolysis, etc. On the other hand, the kidney is the organ responsible for the regulation of hematopoiesis. Renal dysfunction can lead to both anemia and polycythemia. In addition, recent understanding of the MAHA process reveals that the renal microvasculature plays a key role in the pathogenesis. Finally, the failure of the kidney to clear toxins from the body can result in alteration involving hemostasis, as well as leukocyte function and survival.

Managing dialysis patients who develop anemia caused by chronic kidney disease: focus on peginesatide

Anemia in chronic kidney disease is a prevalent and expensive problem in the United States, and it is well documented that anemia worsens as glomerular filtration rates decline. The complications of severe anemia in this patient population contribute significantly to their overall morbidity with increased cardiovascular complications, decreased quality of life, and increased dependence on transfusions to maintain adequate hemoglobin levels. Erythropoietin-stimulating agents (ESAs) have revolutionized the treatment of anemia in this population, but there has been a great deal of controversy surrounding the quest for the ideal hemoglobin target. In addition, there are economic and practice management implications where anemia treatment is concerned, with ongoing refinement of Centers for Medicare and Medicaid Services-bundled payments. One of the newest additions to the arsenal used to fight anemia in end-stage renal disease patients is peginesatide (Omontys), a synthetic, PEGylated, peptide-based ESA that acts by stimulating the erythropoietin receptor. The role of peginesatide in the future treatment of anemia in chronic kidney disease remains uncertain, with new safety concerns being brought to attention as it emerges on the market, prompting a national recall.

Iron deficiency anaemia in chronic kidney disease

BACKGROUND

Iron Deficiency Anaemia (IDA) has been shown to be the most common cause of anaemia worldwide. It is accepted that people with chronic kidney disease (CKD) develop anaemia as their kidney function declines.

METHODS

To better understand IDA in CKD, it is necessary to appreciate the normal iron metabolism and utilisation of iron and how these processes can be disordered in patients with CKD. The problems related to infection / inflammation and oxidative stress are examined. Whilst National and international guidelines recommend specific tests for IDA, these and alternative tests are reviewed.

CONCLUSIONS

Whilst iron supplementation is necessary for CKD patients with IDA, iron metabolism and utilisation can be affected by factors such as infection or inflammation. Iron is essential element for all life, it can be toxic to cells through the process of oxidative stress. The recommended tests for IDA may be affected by factors such as infection and inflammation. Alternative tests are available, which may be a more accurate indicator of IDA as they are not affected by external factors.

Biomarkers of hypochromia: the contemporary assessment of iron status and erythropoiesis

Iron status is the result of the balance between the rate of erythropoiesis and the amount of the iron stores. Direct consequence of an imbalance between the erythroid marrow iron requirements and the actual supply is a reduction of red cell hemoglobin content, which causes hypochromic mature red cells and reticulocytes. The diagnosis of iron deficiency is particularly challenging in patients with acute or chronic inflammatory conditions because most of the biochemical markers for iron metabolism (serum ferritin and transferrin ) are affected by acute phase reaction. For these reasons, interest has been generated in the use of erythrocyte and reticulocyte parameters, available on the modern hematology analyzers. Reported during blood analysis routinely performed on the instrument, these parameters can assist in early detection of clinical conditions (iron deficiency, absolute, or functional; ineffective erythropoiesis, including iron restricted or thalassemia), without additional cost. Technological progress has meant that in recent years modern analyzers report new parameters that provide further information from the traditional count. Nevertheless these new parameters are exclusive of each manufacturer, and they are patented. This is an update of these new laboratory test biomarkers of hypochromia reported by different manufactures, their meaning, and clinical utility on daily practice.