Association of malnutrition-inflammation complex and responsiveness to erythropoiesis-stimulating agents in long-term hemodialysis patients

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.

Roxadustat treatment for erythropoiesis-stimulating agent-hyporesponsive anemia in maintenance hemodialysis patients

OBJECTIVE

Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) is a prevalent problem affecting hemodialysis (HD) patients. Roxadustat is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor that stimulates erythropoiesis and regulates iron metabolism. We explored the ability of roxadustat to increase the hemoglobin (Hb) concentration in ESA-hyporesponsive patients undergoing HD and assessed its effect on iron metabolism and inflammation.

METHODS

This prospective study included 30 patients with ESA-hyporesponsive anemia who had been undergoing stable dialysis. All patients received roxadustat three times per week for 24 weeks. The primary endpoint was the mean change in Hb from baseline to the average level over weeks 20 to 24. Iron metabolism markers, C-reactive protein, interleukin (IL)-6, and safety were also assessed.

RESULTS

At week 24, roxadustat treatment resulted in a 2.5 ± 1.3 g/dL increase in the Hb level. In total, 28 of 30 patients (93.3%) had an Hb level increase of more than 1.0 g/dL from baseline. Seventeen patients (56.7%) met the endpoint, with a mean Hb level of at least 10.0 g/dL. Iron metabolism and IL-6 levels were also improved.

CONCLUSIONS

Oral roxadustat is effective for ESA-hyporesponsive anemia in maintenance HD patients and may also improve iron metabolism and IL-6 levels.

The Associations between Erythropoietic Response with Inflammation Markers and Perfluorinated Chemicals in Hemodialysis Patients

Erythropoiesis-stimulating agents (ESA) are used to treat anemia in hemodialysis (HD) patients. We investigated the role of inflammation and accumulation of environmental toxins (perfluorinated chemicals (PFCs), such as perfluorooctanoic acid and perfluorooctane sulfonate) in the erythropoietic response of HD patients who receive a fixed monthly continuous erythropoietin receptor activator (CERA) dosage. Forty-five patients underwent three successive phases of ESA treatment for two months each (phase one: 100 µg CERA once monthly; phase two: 50 µg CERA twice monthly; phase three: 100 µg CERA once monthly). Patient data were collected to determine the association of various factors with erythropoietic response (change in hematocrit). Liquid chromatography-tandem mass spectrometry was used to analyze perfluorinated chemicals. Twenty-eight patients exhibited a poor erythropoietic response that was significantly associated with: age > 80 years, initial hematocrit > 36%, glucose > 200 mg/dL, alanine aminotransferase > 21 U/L, c-reactive protein > 1 mg/dL, interleukin-6 > 10 ng/mL, lactate dehydrogenase ≤ 190 U/L, and chloride ≤ 93 mEq/L. There was also a borderline significant association between inflammation and PFCs, although PFCs failed to show any impact on ESA response. Age, glucose, chloride, liver function, and inflammation may be associated with cost-effective fixed CERA dosage administered at an increased frequency.

Association between hyporesponsiveness to erythropoiesis-stimulating agents and risk of brain hemorrhage in patients undergoing hemodialysis: the Q-Cohort Study

BACKGROUND

Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) is associated with increased risks of all cause and cardiovascular mortality in patients undergoing hemodialysis (HD). However, the impact of the hematopoietic response to ESAs on the development of stroke, including brain hemorrhage and infarction, remains unclear.

METHODS

In total, 2886 patients undergoing maintenance HD registered in the Q-Cohort Study who were treated with ESAs were prospectively followed up for 4 years. The hematopoietic response to ESAs was evaluated by the erythropoietin resistance index (ERI), calculated by dividing the weekly dose of ESA by post-HD weight and hemoglobin (U/kg/week/g/dL). The primary outcomes were the incidences of brain hemorrhage and infarction. Patients were divided into quartiles based on their ERI at baseline (Q1, ≤ 4.1; Q2, 4.2-7.0; Q3, 7.1-11.2; and Q4, ≥ 11.3). The risks of brain hemorrhage and infarction were estimated using Cox proportional hazards models, adjusting for potential confounders.

RESULTS

During the 4 year follow-up period, 71 patients developed brain hemorrhage and 116 developed brain infarction. In the multivariable analysis, the incidence of brain hemorrhage in the highest quartile (Q4) was significantly higher than that in the lowest quartile (Q1) (hazard ratio [95% confidence interval], 2.18 [1.08-4.42]). However, the association between the ERI and the incidence of brain infarction was not significant.

CONCLUSIONS

A higher ERI was associated with an increased risk of brain hemorrhage, but not brain infarction, in patients undergoing maintenance HD. A high ERI is thus an important risk factor for brain hemorrhage in these patients.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Evolving Concepts on Inflammatory Biomarkers and Malnutrition in Chronic Kidney Disease

While patient care, kidney replacement therapy, and transplantation techniques for chronic kidney disease (CKD) have continued to progress, the incidence of malnutrition disorders in CKD appears to have remained unchanged over time. However, there is now a better understanding of the underlying pathophysiology according to the disease background, disease stage, and the treatment received. In CKD patients, the increased production of proinflammatory cytokines and oxidative stress lead to a proinflammatory milieu that is at least partially responsible for the increased morbidity and mortality in this patient population. New insights into the pathogenic role of innate immunity and the proinflammatory cytokine profile, characterized, for instance, by higher levels of IL-6 and TNF-α, explain some of the clinical and laboratory abnormalities observed in these patients. In this article, we will explore currently available nutritional-inflammatory biomarkers in distinct CKD populations (hemodialysis, peritoneal dialysis, transplantation) with a view to evaluating their efficacy as predictors of malnutrition and their involvement in the common proinflammatory process. Although there is a direct relationship between inflammatory-nutritional status, signs and symptoms [e.g., protein-energy wasting (PEW), anorexia], and comorbidities (e.g., atheromatosis, atherosclerosis), we are in need of clearly standardized markers for nutritional-inflammatory assessment to improve their performance and design appropriate bidirectional interventions.

Association between Body Mass Index and Renal Outcomes Modified by Chronic Kidney Disease and Anemia: The Obesity Paradox for Renal Outcomes

Obesity-related nephropathy is associated with renal function progression. However, some studies have associated a high body mass index (BMI) with improved renal outcomes—this is referred to as the obesity paradox for renal outcomes, especially in relation to advanced chronic kidney disease (CKD). Central obesity can explain the obesity paradox in all-cause mortality. However, whether obesity or central obesity is associated with renal outcomes (renal replacement therapy or a 50% decline in the estimated glomerular filtration rate) in patients with advanced CKD remains unclear. Our study included 3605 Asian patients with CKD stages 1−5 divided into six groups according to their BMI (between 15 and 35 kg/m2). Through linear regression, BMI was positively associated with hemoglobin and albumin at CKD stages 4 and 5. In the competing risk Cox regression model, a high BMI (27.5−35 kg/m2) was associated with renal outcomes at CKD stages 1−3, but not stages 4 and 5. A high BMI was associated with renal outcomes in patients with hemoglobin ≥11 g/dL, but not <11 g/dL. A high waist-to-hip ratio was not associated with renal outcomes. We conclude that the CKD stage and anemia may explain the obesity paradox in renal outcomes in patients with CKD.

Erythropoietin Resistance Development in Hemodialysis Patients: The Role of Oxidative Stress

Oxidative stress (OS) is considered a significant risk factor for the development of anemia in patients treated by regular hemodialysis (HD). Moreover, OS represents a risk factor for the development of erythropoietin (EPO) resistance in these patients. The aim of this study was to examine the role of OS regarding EPO resistance development in patients treated by regular HD. 96 patients treated with standard HD and on-line hemodiafiltration were included in this study. The patients were treated with short-acting and long-acting EPOs for anemia. The concentration of superoxide anion radical, hydrogen peroxide, thiobarbituric acid reactive substances, and nitric oxide in the form of nitrites and the activity of catalase, superoxide dismutase and reduced glutathione were measured in patients' blood spectrophotometrically. Standard biochemical analysis, inflammatory markers, nutritional status, HD parameters, and erythropoietin resistance index were also determined. Patients with resistance to short-acting EPO had significantly lower concentration of hemoglobin in the blood and hematocrit value, a significantly higher serum ferritin concentration, and significantly lower catalase activity in erythrocytes than patients without EPO resistance. Patients with resistance to long-acting EPO have a significantly lower hemoglobin concentration in the blood, hematocrit values, and serum concentration of prealbumin and vitamin D, as well as significantly higher concentration of C-reactive protein, superoxide anion, and hydrogen peroxide concentration than those without resistance. OS significantly contributes to EPO resistance development. OS, higher ferritin and CRP levels, lower hemoglobin, hematocrit and prealbumin levels, and vitamin D deficiency represent significant risk factors for EPO resistance development in HD patients.

Emerging cross-talks between chronic kidney disease-mineral and bone disorder (CKD-MBD) and malnutrition-inflammation complex syndrome (MICS) in patients receiving dialysis

Chronic kidney disease–mineral and bone disorder (CKD–MBD) is a systemic disorder that affects multiple organs and systems and increases the risk of morbidity and mortality in patients with CKD, especially those receiving dialysis therapy. CKD–MBD is highly prevalent in CKD patients, and its treatment is gaining attention from healthcare providers who manage these patients. Additional important pathologies often observed in CKD patients are chronic inflammation and malnutrition/protein-energy wasting (PEW). These two pathologies coexist to form a vicious cycle that accelerates the progression of various other pathologies in CKD patients. This concept is integrated into the term “malnutrition–inflammation–atherosclerosis syndrome” or “malnutrition–inflammation complex syndrome (MICS)”. Recent basic and clinical studies have shown that CKD–MBD directly induces inflammation as well as malnutrition/PEW. Indeed, higher circulating levels of inorganic phosphate, fibroblast growth factor 23, parathyroid hormone, and calciprotein particles, as markers for critical components and effectors of CKD–MBD, were shown to directly induce inflammatory responses, thereby leading to malnutrition/PEW, cardiovascular diseases, and clinically relevant complications. In this short review, we discuss the close interplay between CKD–MBD and MICS and emphasize the significance of simultaneous control of these two seemingly distinct pathologies in patients with CKD, especially those receiving dialysis therapy, for better management of the CKD/hemodialysis population.

Hypoxia-inducible factor prolyl hydroxylase domain inhibitor may maintain hemoglobin synthesis at lower serum ferritin and transferrin saturation levels than darbepoetin alfa

Background

Hypoxia-inducible factor (HIF) prolyl hydroxylase domain inhibitors, which have recently become clinically available for treating renal anemia, are attracting attention for their novel mechanisms of action.

Methods

Relationships of reticulocyte hemoglobin content (CHr), which reflects recent Hb synthesis, with serum ferritin (s-ft) and transferrin saturation (TSAT) were examined in 30 patients on hemodialysis after switching from darbepoetin alfa (DA) to roxadustat (Rox). Iron deficiency was defined as CHr < 32.0 pg. Cutoff values of s-ft and TSAT were determined using receiver operating characteristic curves for the endpoint CHr ≥ 32.0 pg. Logistic analysis was performed with the reference group having s-ft or TSAT below the corresponding cutoff value (low vs high).

Results

With the endpoint CHr ≥ 32.0 pg on Day 0, cutoff values for s-ft and TSAT were respectively 49.7 ng/mL and 21.6% on Day 0 and 35.5 ng/mL and 16.2% on Day 28. With the endpoint CHr ≥ 32.0 pg on Day 28, cutoff values for s-ft and TSAT on Day 0 were 81.6 ng/mL and 23.9%, respectively. According to multivariable logistic analysis, the odds ratios of CHr ≥ 32.0 pg on Day 0 were significantly higher for high TSAT on Day 0 [34.7 (95% CI 2.42–131.0), p<0.003] and Day 28 [24.8 (95% CI 2.75–224.0), p = 0.004]. There were no significant differences by s-ft. Odd ratios of CHr ≥ 32.0 pg on Day 28 were also significantly higher for high s-ft on Day 0 [16.0 (95% CI 1.57–163.0), p = 0.019] and high TSAT on Day 0 [13.5 (95% CI 1.24–147.0), p<0.033].

Conclusions

Our results suggest Hb synthesis was maintained with lower TSAT and s-ft during Rox therapy compared with DA therapy. To avoid iron deficiency during the 4 weeks after switching DA to Rox, ideal s-ft and TSAT levels before the switch are 81.6 ng/mL and 23.9%, respectively.

Hyporesponsiveness to long-acting erythropoiesis-stimulating agent is related to the risk of cardiovascular disease and death in Japanese patients on chronic hemodialysis: observational cohort study

Background

Responsiveness to erythropoiesis-stimulating agents (ESAs) is thought to be related to prognosis in patients on hemodialysis. A multi-center, prospective cohort study was conducted to investigate the effects of hyporesponsiveness to long-acting ESAs on cardiovascular events and mortality in Japanese patients on chronic hemodialysis.

Methods

A total of 127 chronic hemodialysis patients treated with long-acting ESAs were followed-up prospectively. Responsiveness to ESA was evaluated using an erythropoietin resistance index (ERI) calculated by dividing the weekly body-weight-adjusted ESA dose by the hemoglobin concentration. The primary endpoint of this survey was defined as a combination of cardiovascular events and all-cause deaths. The association between hyporesponsiveness to ESAs evaluated by the highest quartile of the ERI and the primary endpoint was investigated.

Results

During the follow-up period (median 4.6 years), 32 patients reached the primary end point. Kaplan-Meier curve analysis showed that patients with ESA hyporesponsiveness belonging to the highest quartile of the ERI reached the primary end point more frequently than those without (P = 0.031). Cox regression analysis showed that an ERI in the highest quartile was an independent predictor of the primary end point, even after adjustment using a propensity score (hazard ratio 2.76, 95% confidence interval 1.19–6.40).

Conclusions

ESA hyporesponsiveness in hemodialysis patients treated with long-acting ESAs is related to cardiovascular events and death.

Phase angle values, a good indicator of nutritional status, are associated with median value of hemoglobin rather than hemoglobin variability in hemodialysis patients

Background

Our aim was to elucidate whether Hb variability affects nutritional status in HD patients.

Methods

This study included chronic HD patients (n = 76) with available monthly Hb levels up to 24 months prior to the body composition monitoring (BCM) measurement. The parameters obtained in the BCM included body mass index (BMI), lean tissue index (LTI), fat tissue index (FTI), body cell mass index (BCMI), overhydration/extracellular water ratio (OH), and phase angle (PhA). The coefficient of variation (Hb-CV), standard deviation (Hb-SD), and range of Hb (Hb-RAN) were used as indexes of Hb variability. In addition, minimum (Hb-Min), maximum (Hb-Max), average (Hb-Avg), and median (Hb-Med) Hb levels (g/dL) were analyzed.

Results

There were no significant differences in clinical, biochemical, and nutritional indexes based on the Hb-CV level. Compared to patients with an Hb-Med ≤ 10.77, those with an Hb-Med >10.77 had higher albumin levels, total iron-binding capacity (TIBC), and PhA and lower average weekly prescribed darbepoetin. Age, female sex, OH, and darbepoetin dosage were negatively correlated with PhA. Serum albumin, phosphorus, TIBC, Hb-Med, and Hb-Avg were positively correlated with PhA. In multiple linear regression analysis, PhA was positively associated with Hb-Med and serum albumin level, whereas PhA was negatively associated with age and female sex. The area under the curve (AUC) of Hb-Med was 0.665 (p = 0.040) in predicting PhA >5.00°

Conclusions

PhA was not affected by indexes of Hb variability, whereas PhA was associated with Hb-Med in chronic HD patients.

The association of erythropoietin-stimulating agents and increased risk for AV-fistula dysfunction in hemodialysis patients. A retrospective analysis

BACKGROUND

Patients in maintenance hemodialysis (HD) need a patent vascular access for optimal treatment. The recommended first choice is a native arteriovenous fistula (AVF). Complications of AVF are frequent and include thrombosis, stenosis and infections leading to worsening of dialysis efficacy. Some known risk factors are age, gender and the presence of diabetes mellitus. The aim was to investigate if further risk variables are associated with dysfunctional AVF.

METHODS

This retrospective observational study included 153 chronic HD patients (Cases) referred to a total of 473 radiological investigations due to clinically suspected complications of their native AVF. Another group of chronic HD patients (n = 52) who had a native AVF but were without history of previous complications for at least 2 years were controls. Statistical analyses included ANOVA, logistic regression, parametric and non-parametric methods such as Student's T-test and Mann-Whitney test.

RESULTS

Among Cases, at least one significant stenosis (> 50% of the lumen) was detected in 348 occasions. Subsequent PTA was performed in 248 (71%). Median erythropoiesis-stimulating agent (ESA) weekly doses were higher in Cases than in Controls (8000 vs 5000 IU, p < 0.001). Cases received higher doses of intravenous iron/week than the Controls before the investigation (median 50 mg vs 25 mg, p = 0.004) and low molecular weight heparin (LMWH, p = 0.028). Compared to Controls, Cases had a lower level of parathyroid hormone (median 25 vs 20 ρmol/L, p = 0.009). In patients with diabetes mellitus, HbA1c was higher among Cases than Controls (50 vs 38 mmol/mol, p < 0.001). Multiple regression analysis revealed significant associations between Cases and female gender, prescription of doxazocin, and doses of ESA and LMWH. There was no difference between the groups regarding hemoglobin, CRP or ferritin.

CONCLUSION

In conclusion, the present study indicated that the factors associated with AVF problems were high doses of ESA, iron administration, and tendency of thromboembolism (indicated by high LMWH doses); the use of doxazocin prescription, however, requires further investigation.

Association of the erythropoiesis-stimulating agent resistance index and the geriatric nutritional risk index with cardiovascular mortality in maintenance hemodialysis patients

OBJECTIVE

Hyporesponsiveness to erythropoiesis-stimulating agent (ESA) may be associated with protein-energy wasting. We investigated the relationship of the ESA resistance index (ERI) and the geriatric nutritional risk index (GNRI) for cardiovascular mortality in hemodialysis (HD) patients.

METHODS

A total of 180 maintenance HD patients were enrolled. The patients were stratified by the GNRI of 91.2, a previously reported cut-off value, and the ERI of 13.7 (IU/week/kg/g/dL), a cut-off value for predicting cardiovascular-specific mortality, and they were classified into four groups (group 1[G1]: higher GNRI and lower ERI, G2: higher GNRI and higher ERI, G3: lower GNRI and lower ERI, G4: lower GNRI and higher ERI).

RESULTS

The ERI was independently associated with the GNRI (β = -0.271, p = 0.0005). During a median follow-up of 4.6 years, higher ERI and lower GNRI were independently associated with cardiovascular mortality, respectively (adjusted hazard ratio [aHR], 3.10; 95% confidence interval [CI], 1.31-7.34, and aHR, 6.64; 95%CI, 2.60-16.93, respectively). The 7-year survival rates were 96.1%, 70.3%, 77.3%, and 50.1% in G1, G2, G3, and G4, respectively. The aHR values for G4 versus G1 were 12.63 (95%CI, 3.58-44.59). With regards to model discrimination, adding the GNRI alone, the ERI alone, and both to the traditional risk model significantly improved the net reclassification improvement by 0.421, 0.662, and 0.671, respectively. Similar results were obtained for all-cause mortality.

CONCLUSION

The ERI was independently associated with the GNRI, and could predict cardiovascular mortality in HD patients. Moreover, the combination of GNRI and ERI could improve the predictability for cardiovascular mortality.

Association of erythropoietin resistance and fibroblast growth factor 23 in dialysis patients: Results from the Japanese Dialysis Outcomes and Practice Patterns Study

BACKGROUND

Fibroblast growth factor 23 (FGF23) plays an important role in chronic kidney disease (CKD)-related mineral and bone disorders. High FGF23 levels are associated with increased risk of anaemia in non-haemodialysis CKD patients. FGF23 also negatively regulates erythropoiesis in mice. We hypothesized that higher FGF23 levels are associated with increased erythropoietin hyporesponsiveness among haemodialysis patients.

METHODS

The study included 1044 patients from the Japanese Dialysis Outcomes and Practice Patterns Study (J-DOPPS) phase 5 (2012-2015). The outcome was erythropoiesis-stimulating agent hyporesponsiveness (ESA-hypo), defined as mean Hgb <10 g/dL and standardized mean ESA dose >6000 u/week over 4 months following FGF23 measurement. The association between ESA-hypo and FGF23 was estimated using multivariable-adjusted logistic generalized estimating equation regression models.

RESULTS

Patients with higher levels of FGF23 were younger and had higher levels of serum albumin, creatinine, albumin-corrected calcium, phosphorus, PTH, 25(OH)-vitamin D, and had higher percentages of intravenous (IV) iron, IV vitamin D and cinacalcet use. ESA-hypo was present in 144 patients (13.8%). Compared with the third quintile of FGF23 levels, the odds ratio (95% CI) of ESA-hypo was 2.14 (0.99, 4.62) and 1.74 (0.74, 4.11) for the first and fifth quintiles, respectively.

CONCLUSION

The lowest and highest levels of FGF23 were associated with higher odds of ESA-hypo in patients on maintenance haemodialysis, although the associations were not statistically significant. The relationship between FGF23 and anaemia, and particularly the increased risks of ESA-hypo at low FGF23 levels which might be the result of energy saving, must be confirmed in larger clinical studies.

[Clinical characteristics and treatment outcomes of first peritonitis in patients receiving long-term peritoneal dialysis: a multicenter study]

OBJECTIVE

To analyze the clinical characteristics and treatment outcomes of the first episode of peritoneal dialysis-associated peritonitis (PDAP) in patients receiving long-term peritoneal dialysis.

METHODS

The clinical data of patients with the first episode of PDAP in 4 general hospitals in Jilin Province from 2013 to 2019 were collected retrospectively. According to the duration of dialysis, the patients were divided into long-term (≥36 months) and short-term (< 36 months) dialysis groups for comparison of the clinical data, treatment outcomes and long-term prognostic events.

RESULTS

A total of 625 patients with PDAP were enrolled, including 93 on long-term and 532 on short-term dialysis. Compared with those on short-term dialysis, the patients on long-term dialysis had significantly higher hemoglobin levels and lower glomerular filtration rates when the first episode of PDAP occurred (P < 0.05), were more susceptible to gram-negative bacterial infections (P < 0.05), and had significantly lower initial treatment response rate (P=0.009) and complete cure rate (P=0.018) and higher extubation rate (P=0.017). Multivariate logistic regression analysis showed that in patients on long-term dialysis, the risks of extubation and treatment failure for the first episode of PDAP were 3.05 times (OR: 3.05, 95%CI: 1.35-6.91, P=0.008) and 2.81 times (OR: 2.81, 95%CI: 1.45-5.44, P=0.002) those in patients with short-term dialysis, respectively. Fungal infection (OR: 45.40, 95%CI: 1.488-1385.5, P=0.029) and mixed bacterial infection (OR: 16.50, 95%CI: 1.106-246.123, P=0.042) were independent risk factors for treatment failure of the first episode of PDAP in patients on long-term dialysis. Maintenance peritoneal dialysis, technical failure, or all-cause mortality did not differ significantly between the two groups. Multivariate Cox regression analysis suggested that long-term dialysis was not an independent risk factor for technical failure (OR: 1.36, 95%CI: 0.84-2.19, P=0.206) or all-cause mortality (OR: 1.51, 95%CI: 0.97-2.35, P=0.068) in patients with PDAP.

CONCLUSIONS

Compared with those on short-term dialysis, patients on long-term dialysis are prone to gram-negative bacterial infection when the first episode of PDAP occurs with worse treatment outcomes but similar long-term outcomes. Long-term dialysis is an independent risk factor of extubation and treatment failure for the first episode of PDAP, and fungal and mixed bacterial infections are independent risk factors for treatment failure of the first PDAP in patients with long-term dialysis.

The Influence of Altitude on Erythropoietin Resistance Index in Maintenance Hemodialysis Patients: Data from Tibetan Plateau

BACKGROUND

It is known that hypoxia influences many of the biologic processes involved in erythropoiesis; therefore, the high-altitude hypoxia may affect erythropoietin (EPO) responsiveness in maintenance hemodialysis (MHD) patients. This study aimed to evaluate the impact of altitude on EPO responsiveness in MHD patients.

METHODS

In this retrospective study, MHD patients from Tibet Autonomous Region People's Hospital (3,650 m above sea level) and Peking University People's Hospital (43.5 m above sea level) were recruited between May 2016 and December 2018. Patients were divided into 2 groups according to altitude. Variables including age, sex, dialysis vintage, dialysis modality, duration of EPO use, EPO doses, and laboratory tests were collected and analyzed. EPO responsiveness was measured in terms of the EPO resistance index (ERI). ERI was defined as the weekly weight-adjusted dose of EPO (IU/kg/week) divided by hemoglobin concentration (g/dL). The association between ERI and altitude was estimated using a multivariable linear regression model.

RESULTS

Sixty-two patients from Tibet Autonomous Region People's Hospital (high-altitude [HA] group) and 102 patients from Peking University People's Hospital (low-altitude [LA] group) were recruited. The ERI for HA group and LA group was 6.9 ± 5.1 IU w-1 kg-1 (g/dL)-1 and 11.5 ± 6.4 IU w-1 kg-1 (g/dL)-1, respectively. After adjusting for covariates by multivariable regression, altitude was independently associated with ERI (R2 = 0.245, p < 0.001).

CONCLUSION

Altitude had an independent negative correlation with ERI. This result supported the hypothesis that altitude-associated hypoxia improved EPO responsiveness in MHD patients.

Erythropoietin Resistance in Patients with Chronic Kidney Disease: Current Perspectives

Anemia is a frequent complication of chronic kidney disease, and its primary cause is erythropoietin deficiency. After diagnosis, treatment begins with administration of an erythropoiesis-stimulating agent (ESA). However, some patients present with resistance to ESA, which needs to be reversed, as it can increase the risk of death in patients with kidney disease. Therefore, we provide a discussion of the current literature regarding the factors that can modify the response to this class of drugs and the strategies that can be considered to optimize the benefits of treating anemia.

A Hypoxia-Inducible Factor Stabilizer Improves Hematopoiesis and Iron Metabolism Early after Administration to Treat Anemia in Hemodialysis Patients

Roxadustat (Rox), a hypoxia-inducible factor (HIF) stabilizer, is now available for the treatment of anemia in hemodialysis (HD) patients. To investigate hematopoietic effect and iron metabolism, this study involved 30 HD patients who were initially treated with darbepoetin (DA), a conventional erythropoietin-stimulating agent, and then switched to Rox. We measured erythrocyte, reticulocyte indices, and iron-related factors at every HD during the first two weeks after the treatment switch (Days 0–14) and again on Days 21 and 28. We measured erythropoietin (EPO) concentration every week and examined their changes from Day-0 values. The same variables were measured in 15 HD patients who continued DA at every HD for one week. Iron-related factors were also measured on Days 14 and 28. In the Rox group, hepcidin significantly decreased from Day 2. The reticulocyte hemoglobin content (CHr) significantly increased on Day 4, but decreased with a significant increase in reticulocyte count from Day 7. Log₁₀(serum ferritin) significantly decreased after Day 11. Log₁₀(EPO concentration) was lower at all time points. Compared with the DA group, the Rox group showed significant differences in all variables except CHr. These results suggest that Rox improves hematopoiesis and iron metabolism early after administration independent of EPO concentration.

A Novel Choice to Correct Inflammation-Induced Anemia in CKD: Oral Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitor Roxadustat

Anemia is a complication of chronic kidney disease (CKD), primarily due to insufficient secretion of erythropoietin (EPO) by the kidney. Erythropoiesis-stimulating agents (ESAs) are used to treat anemia associated with chronic kidney disease. A poor response to ESAs has been associated with inflammation. Inflammation can affect erythrocytes and its production in many ways, but mainly through the inflammatory cytokine IL-6 to stimulate the synthesis of hepcidin in the liver. Hepcidin causes iron insufficiency, which causes erythrocytes to fail to mature normally. In addition, inhibition of bone marrow erythroid precursor cells by inflammatory cytokines such as IL-1 and TNF-α also affects bone marrow hematopoiesis. These cytokines are also important factors leading to EPO resistance. Roxadustat is a new drug for the treatment of renal anemia. In addition to promoting the production of EPO, clinical trials have shown that it can significantly reduce hepcidin and can potentially be used for the treatment of inflammation-induced anemia in CKD.

Inflammation and Erythropoiesis-Stimulating Agent Response in Hemodialysis Patients: A Self-matched Longitudinal Study of Anemia Management in the Dialysis Outcomes and Practice Patterns Study (DOPPS)

Rationale & Objective

Previous studies of inflammation and anemia management in hemodialysis (HD) patients may be biased due to patient differences. We used a self-matched longitudinal design to test whether new inflammation, defined as an acute increase in C-reactive protein (CRP) level, reduces hemoglobin response to erythropoiesis-stimulating agent (ESA) treatment.

Study Design

Self-matched longitudinal design.

Setting & Participants

3,568 new inflammation events, defined as CRP level > 10 mg/L following a 3-month period with CRP level ≤ 5 mg/L, were identified from 12,389 HD patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 4 to 6 (2009-2018) in 10 countries in which CRP is routinely measured.

Predictor

“After” (vs “before”) observing a high CRP level.

Outcomes

Within-patient changes in hemoglobin level, ESA dose, and ESA hyporesponsiveness (hemoglobin < 10 g/dL and ESA dose > 6,000 [Japan] or >8,000 [Europe] U/wk).

Analytical Approach

Linear mixed models and modified Poisson regression.

Results

Comparing before with after periods, mean hemoglobin level decreased from 11.2 to 10.9 g/dL (adjusted mean change, −0.26 g/dL), while mean ESA dose increased from 6,320 to 6,960 U/wk (adjusted relative change, 8.4%). The prevalence of ESA hyporesponsiveness increased from 7.6% to 12.3%. Both the unadjusted and adjusted prevalence ratios of ESA hyporesponsiveness were 1.68 (95% CI, 1.48-1.91). These associations were consistent in sensitivity analyses varying CRP thresholds and were stronger when the CRP level increase was sustained over the 3-month after period.

Limitations

Residual confounding by unmeasured time-varying risk factors for ESA hyporesponsiveness.

Conclusions

In the 3 months after HD patients experienced an increase in CRP levels, hemoglobin levels declined quickly, ESA doses increased, and the prevalence of ESA hyporesponsiveness increased appreciably. Routine CRP measurement could identify inflammation as a cause of worsened anemia. In turn, these findings speak to a potentially important role for anemia therapies that are less susceptible to the effects of inflammation.

Intradialytic Nutrition and Hemodialysis Prescriptions: A Personalized Stepwise Approach

Dialysis and nutrition are two sides of the same coin—dialysis depurates metabolic waste that is typically produced by food intake. Hence, dietetic restrictions are commonly imposed in order to limit potassium and phosphate and avoid fluid overload. Conversely, malnutrition is a major challenge and, albeit to differing degrees, all nutritional markers are associated with survival. Dialysis-related malnutrition has a multifactorial origin related to uremic syndrome and comorbidities but also to dialysis treatment. Both an insufficient dialysis dose and excessive removal are contributing factors. It is thus not surprising that dialysis alone, without proper nutritional management, often fails to be effective in combatting malnutrition. While composite indexes can be used to identify patients with poor prognosis, none is fully satisfactory, and the definitions of malnutrition and protein energy wasting are still controversial. Furthermore, most nutritional markers and interventions were assessed in hemodialysis patients, while hemodiafiltration and peritoneal dialysis have been less extensively studied. The significant loss of albumin in these two dialysis modalities makes it extremely difficult to interpret common markers and scores. Despite these problems, hemodialysis sessions represent a valuable opportunity to monitor nutritional status and prescribe nutritional interventions, and several approaches have been tried. In this concept paper, we review the current evidence on intradialytic nutrition and propose an algorithm for adapting nutritional interventions to individual patients.

Relationship between anti-erythropoietin receptor autoantibodies and responsiveness to erythropoiesis-stimulating agents in patients on hemodialysis: a multi-center cross-sectional study

BACKGROUND

A decreased response to erythropoiesis-stimulating agents (ESAs) leads to refractory anemia and worse prognosis in patients with chronic kidney disease. We examined the association between autoantibodies to the erythropoietin receptor (EPOR) and responsiveness to ESAs in patients on maintenance hemodialysis.

METHODS

A total of 108 Japanese patients on maintenance hemodialysis at three institutions were enrolled. Sera from these patients were screened for anti-EPOR antibodies using an enzyme-linked immunosorbent assay. An ESA resistance index (ERI) was calculated, and patients in the highest ERI quartile were defined as ESA hyporesponsive.

RESULTS

Anti-EPOR antibodies were detected in 11 patients (10%). Body mass index and hemoglobin, platelet, magnesium, and ferritin levels decreased with higher ERI levels. On the other hand, C-reactive protein (CRP) levels and the prevalence of anti-EPOR antibodies increased with higher ERI levels. In multivariate analysis, the presence of anti-EPOR antibodies together with CRP was a significant risk factor for ESA hyporesponsiveness.

CONCLUSIONS

Anti-EPOR antibodies were detected in patients on maintenance hemodialysis, and these autoantibodies were independent factors for hyporesponsiveness to ESAs in these patients.

Relationship between protein-energy wasting in adults with chronic hemodialysis and the response to treatment with erythropoietin

BACKGROUND

It is known that one of the leading causes of morbidity in chronic kidney disease (CKD) is the anemic syndrome. Although the pathogenic mechanisms of anemia are multiple, erythropoietin deficiency appears as the dominant factor. Patients in hemodialysis (HD) have a high prevalence of protein energy wasting (PEW) that may explains the poor response to Erythropoietin (EPO).

METHODS

Retrospective cohort study of patients on HD from January to December 2014. The participants were classified according to a diagnostic of PEW using the "Malnutrition Inflammation Score" (MIS) and bioimpedance analysis (BIA) measurement of body composition at the start of erythropoietin therapy and after 3 months of follow up. We performed descriptive statistics and analyzed the differences between groups with and without PEW considering their responsiveness. In addition, we calculated the relative risk of EPO resistance, considering p value < 0.05 as statistically significant.

RESULTS

Sixty-one patients ended the follow up. Both groups were similar in basal hemoglobin, hematocrit and other hematopoiesis markers (p = NS). Patients without PEW have a decrease risk for poor response to treatment with EPO (RR = 0.562 [95% CI, 0.329-0.961-]) than those with PEW. Finally, hemoglobin concentrations were evaluated at baseline and every four weeks until week 12, finding a statistically significant improvement only in patients without PEW according MIS (p < 0.05).

CONCLUSIONS

PEW is an incremental predictor of poor responsiveness to EPO in HD patients, thus, it is important to consider correcting malnutrition or wasting for a favorable response to treatment with EPO.

Assessment of Severity of Illness and Monitoring Response to Treatment of Odontogenic Space Infection Using Serum Prealbumin

PURPOSE

To assess Serum Prealbumin in the severity of illness and monitor response to treatment in odontogenic space infection.

PATIENTS AND METHODS

This was a prospective cohort study comprising patients being managed for odontogenic space infection at the Obafemi Awolowo University Teaching Hospital, Ile-Ife, Nigeria. The calculated sample size was 69. Clinical parameters (Swelling Size, Visual Analogue Scale for pain intensity, and Maximal Interincisal Distance) were measured on day 0, day 4, and day 8. Other clinical parameters were Number of Anatomic Spaces Involved, setting of treatment, and Length of Hospital Stay. Serum Prealbumin levels were also serially measured. The relationship between Serum Prealbumin level and the clinical parameters was established using Spearman's correlation test, independent t test, Friedman's test, and linear regression. Significance level was set at .05.

RESULTS

The mean Serum Prealbumin level at presentation (day 0) was 19.19 ± 4.61 mg/dl, which was significantly lower among inpatients (p = 0.001). On days 0, 4, and 8, Serum Prealbumin negatively correlated with Number of Anatomic Spaces Involved (p < 0.001). Serum Prealbumin levels on days 0, 4, and 8 and response in Serum Prealbumin negatively correlated with Length of Hospital Stay. On each day, Serum Prealbumin negatively correlated with pain intensity and Swelling Size and positively correlated with mouth opening. The response in Serum Prealbumin also positively correlated with response in each of the three clinical parameters.

CONCLUSION

This study suggests that Serum Prealbumin is a reliable tool for grading severity of illness and monitoring response to treatment in odontogenic space infection.

Interleukin-6 Contributes to the Development of Anemia in Juvenile CKD

Introduction

Anemia is a common complication of chronic kidney disease (CKD) in children; however, the role of inflammation in its pathogenesis remains incompletely understood.

Methods

To elucidate the role of interleukin (IL)-6 in renal anemia, we induced CKD by adenine diet in juvenile wild-type (WT) and IL-6 deficient (Il6KO) mice, and examined serum IL-6 and relevant parameters in children with CKD.

Results

WT-CKD mice developed anemia despite increases in serum erythropoietin and displayed low serum iron and elevated serum IL-6. IL-6 deficiency resulted in a significant improvement of red blood cell count and hemoglobin in CKD mice. This effect was associated with improvement of hypoferremia by Il6 deletion, likely mediated by hepcidin. However, correction of hypoferremia by oral iron supplementation in WT-CKD mice did not fully replicate the protective effects of Il6 deletion, suggesting an additional iron-independent role for IL-6 in CKD-anemia. Indeed, Il6 deletion mitigated the severity of renal fibrosis and alleviated relative erythropoietin insufficiency in CKD mice. Cytokine profiling in a pediatric CKD cohort demonstrated that of 10 cytokines (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, tumor necrosis factor (TNF)-α, and interferon-γ), only IL-6 was significantly (inversely) associated with hemoglobin when adjusted for glomerular filtration rate (GFR). The association between IL-6 and hemoglobin in children with CKD remained significant after adjustment for CKD stage, iron therapy, and hepcidin.

Discussion

IL-6 contributes to development of anemia in juvenile CKD, through mechanisms that include induction of hypoferremia, aggravation of renal fibrosis, and alteration of the erythropoietin axis. IL-6 appears to be a promising therapeutic target in the management of CKD-anemia.

A Retrospective Study on Erythropoiesis Stimulating Agent Dose Reducing Potential of an Anti-Platelet Activation Membrane Dialyzer in Hemodialysis Patients

Our previous small‐scale trial demonstrated an erythropoiesis stimulating agent (ESA)‐sparing potential of the TORAYLIGHT NV (NV) dialyzer in hemodialysis patients with high interleukin‐6 levels. We now retrospectively explored this ESA‐sparing potential of the NV dialyzer in 122 and 129 prevalent dialysis patients who were on the NV and conventional polysulfone (PS) dialyzers, respectively, for 12 months. ESA resistance index (ERI) increased with the PS dialyzers whereas neither ERI nor ESA dose changed with the NV dialyzer. Analyses of baseline ERI or ESA dose‐based subgroups revealed a decrease in ERI and ESA dose with the NV dialyzer in patients with a baseline ERI ≥12 IU·dL/week·kg·g Hb (P < 0.05) and in those with a baseline ESA dose >6000 IU/week (P < 0.001), respectively. Neither ERI nor ESA dose improved in the corresponding subgroups on the PS dialyzers. These findings suggest that NV dialyzer can improve ESA responsiveness in hemodialysis patients with advanced ESA resistance.

Pathogenesis and Treatment Options of Cancer Related Anemia: Perspective for a Targeted Mechanism-Based Approach

Cancer-related anemia (CRA) is a common sign occurring in more than 30% of cancer patients at diagnosis before the initiation of antineoplastic therapy. CRA has a relevant influence on survival, disease progression, treatment efficacy, and the patients' quality of life. It is more often detected in patients with advanced stage disease, where it represents a specific symptom of the neoplastic disease, as a consequence of chronic inflammation. In fact, CRA is characterized by biological and hematologic features that resemble those described in anemia associated to chronic inflammatory disease. Proinflammatory cytokine, mainly IL-6, which are released by both tumor and immune cells, play a pivotal action in CRA etiopathogenesis: they promote alterations in erythroid progenitor proliferation, erythropoietin (EPO) production, survival of circulating erythrocytes, iron balance, redox status, and energy metabolism, all of which can lead to anemia. The discovery of hepcidin allowed a greater knowledge of the relationships between immune cells, iron metabolism, and anemia in chronic inflammatory diseases. Additionally, chronic inflammation influences a compromised nutritional status, which in turn might induce or contribute to CRA. In the present review we examine the multifactorial pathogenesis of CRA discussing the main and novel mechanisms by which immune, nutritional, and metabolic components affect its onset and severity. Moreover, we analyze the status of the art and the perspective for the treatment of CRA. Notably, despite the high incidence and clinical relevance of CRA, controlled clinical studies testing the most appropriate treatment for CRA are scarce, and its management in clinical practice remains challenging. The present review may be useful to indicate the development of an effective approach based on a detailed assessment of all factors potentially involved in the pathogenesis of CRA. This mechanism-based approach is essential for clinicians to plan a safe, targeted, and successful therapy, thereby promoting a relevant amelioration of patients' quality of life.

Anemia Is Correlated with Malnutrition and Inflammation in Croatian Peritoneal Dialysis Patients: A Multicenter Nationwide Study

Malnutrition, inflammation, and anemia are common in peritoneal dialysis (PD) patients. In this study, correlations between Malnutrition Inflammation Score (MIS), laboratory and anthropometric parameters, and anemia indices in Croatian PD patients were analyzed. One hundred and one PD patients (males/females 54/47, age 58.71 ± 14.68 years, mean PD duration 21.82 ± 21.71 months) were included. Clinical, laboratory, and anthropometric parameters were measured. Statistically significant correlations between MIS and erythropoietin weekly dose per kg of body weight (ESA weekly dose), hemoglobin (Hb), and erythrocytes were found (r = 0.439, p < 0.001; r = -0.032, p < 0.001; r = -0.435, p < 0.001), respectively. Also, statistically significant correlations were found between MIS and mean corpuscular volume (r = 0.344, p < 0.001), iron (r = -0.229, p = 0.021), and total iron binding capacity (TIBC) (r = -0.362, p < 0.001), respectively. Furthermore, statistically significant correlations between ESA weekly dose and serum albumin level and body mass index (BMI) were found (r = -0.272, p = 0.006; r = -0.269, p = 0.006), respectively. When we divided PD patients into 2 groups according Hb level (Hb ≥ 110 [N = 60, 59.41 %]) and Hb < 110 [N = 41, 40.59%]), statistically significant differences were found in MIS score (3.02 ± 2.54 vs 4.54 ± 3.54, p = 0.014), C-reactive protein (CRP) (3.52 ± 6.36 vs 7.85 ± 7.96, p = 0.005), and serum albumin level (44.22 ± 8.54 vs 39.94 ± 8.56, p = 0.003), respectively. Our findings suggest that anemia is correlated with malnutrition and inflammation in Croatian PD patients. Further studies are needed to assess whether modulating inflammatory or nutritional processes can improve anemia management in PD patients.

Butyrylcholinesterase level as an independent factor of erythropoiesis-stimulating agent resistance in patients on maintenance hemodialysis: a single-center cross-sectional study

BACKGROUND

Erythropoiesis-stimulating agent (ESA) responsiveness is related to the nutritional status of patients on hemodialysis (HD). Serum butyrylcholinesterase (BChE), an alpha-glycoprotein, may decrease in case of malnutrition. We investigated whether BChE was independently related to ESA resistance in patients on HD.

METHODS

The laboratory data and ESA resistance index (ERI), defined as ESA dosage per week divided by dry weight and hemoglobin, were investigated in 215 patients on HD between July and September 2017. Malnutrition was defined as Geriatric Nutritional Risk Index (GNRI) of < 91.2. The patients were stratified into two groups: ERI-high (ERI ≥ 9.44) and ERI-low (ERI < 9.44) groups. Variables such as patient's background, medication, and laboratory data were compared between the two groups. The optimal cutoff value of BChE for higher ERI was determined using receiver operating characteristic analysis. Factors independently associated with higher ERI were determined using multivariate logistic regression analysis.

RESULTS

The median and optimal cutoff values of ERI and BChE were 6.51 and 200 IU/L, respectively. The study included 71 (33%) and 144 (67%) patients in the ERI-high and ERI-low groups, respectively. Significant between-group differences were observed concerning age, hemoglobin, ESA dose, lipid profiles, serum albumin, body mass index, GNRI, iron metabolism markers, ferric medicines, and BChE. Multivariate analysis showed that BChE < 200 IU/L (odds ratio 3.67; 95% confidence interval 1.73-7.77) continued to be an independent factor associated with higher ERI after adjusting for potential confounders, which was a similar odds ratio as GNRI < 91.2.

CONCLUSION

BChE may be an independent indicator of ESA resistance.

Nutritional status in short daily hemodialysis versus conventional hemodialysis patients in China

PURPOSE

Malnutrition is the main determinant of mortality and morbidity in maintenance hemodialysis patients. In many countries except for China, it has been reported that short daily hemodialysis (SDHD) could improve nutritional status. We will report here the nutritional results obtained in the SDHD therapy period compared with conventional hemodialysis (cHD) therapy period in Chinese patients.

METHODS

This study compared 29 SDHD patients (SDHD group), each patient served as his own control, with 30 cHD patients (cHD group) serving as the parallel controls. The hematologic parameters, anthropometric measurements, modified quantitative subjective global assessment (MQSGA) score, weekly standard Kt/V (std Kt/V) and average daily intake of protein were measured at baseline (SDHD₀ or cHD₀ period), at 3 months (SDHD₁ or cHD₁ period) and at 6 months (SDHD₂ or cHD₂ period).

RESULTS

The average daily intake of protein, dry weight, body mass index, mid-arm circumference, mid-arm muscle circumference, serum albumin, prealbumin, cholesterol, hemoglobin, weekly std Kt/V values at SDHD₂ were higher than the corresponding values at SDHD₀ (p < 0.05, p < 0.05, p < 0.001, p < 0.05, p < 0.05, p < 0.05, p < 0.001, p < 0.05, p < 0.05, p < 0.001 and p < 0.001, respectively). Meanwhile, the average daily intake of protein, serum albumin, prealbumin, cholesterol, hemoglobin, weekly std Kt/V values at SDHD₂ were higher than the corresponding values at cHD₂ (p < 0.05, p < 0.001, p < 0.05, p < 0.05, p < 0.001 and p < 0.001, respectively), whereas the MQSGA score at SDHD₂ was lower than the score at SDHD₀ and cHD₀ (p < 0.05, respectively).

CONCLUSIONS

SDHD may improve the nutritional status compared with cHD in Chinese patients undergoing maintenance hemodialysis.

Prevalence of malnutrition-inflammation complex syndrome and its correlation with thyroid hormones in chronic haemodialysis patients

INTRODUCTION

Low levels of thyroid hormones, total triiodothyronine (T3) and free triiodothyronine (FT3) in haemodialysis patients is a marker of malnutrition and inflammation and are predictors of mortality. The aim of this study was to determine the prevalence of malnutrition-inflammation complex syndrome in haemodialysis and its relationship with the thyroid hormones thyrotropin, T3, FT3 and free thyroxine (FT4), as well as to evaluate the prevalence of low FT3 syndrome and its correlation with nutritional and inflammatory markers.

MATERIALS AND METHODS

Cross-sectional, analytical and comparative study that enrolled 128 haemodialysis patients: 50.8% females; mean age 45.05±17.01 years; mean time on haemodialysis 45.4±38.8 months; 29.7% diabetics; 79.7% with hypertension. Serum thyroid hormones thyrotropin, T3, FT3 and FT4 concentrations were measured and Malnutritition-Inflammation Score (MIS) was applie to diagnostic.

RESULTS

Mean thyroid hormone values were: thyroid hormones thyrotropin 2.48±1.8 mIU/ml (range: 0.015-9.5), T3 1.18±0.39 ng/ml (range 0.67-2.64), FT3 5.21±0.96pmol/l (range: 3.47-9.75); FT4 1.35±0.4 ng/ml (range: 0.52-2.57). Malnutrition-inflammation complex syndrome prevalence was 53.9%; 11.7% presented low FT3 levels. Serum T3 and FT3 concentrations inversely correlated with Malnutritition-Inflammation Score (MIS), while FT4 correlated positively with Malnutrition-Inflammation Score. In the linear regression analysis, low FT3 was associated with IL-6 (β= 0.265, p=.031), C-reactive protein (CRP) (β= -0.313, p=.018) and albumin (β= 0.276, p=.002).

CONCLUSION

Low T3 and FT3 levels are correlated with malnutrition and inflammation parameters. Malnutrition-inflammation complex syndrome can affect serum concentrations of thyroid hormones.

Hemodialysis Disparities in African Americans: The Deeply Integrated Concept of Race in the Social Fabric of Our Society

End-stage renal disease (ESRD) is one of the starkest examples of racial/ethnic disparities in health. Racial/ethnic minorities are 1.5 to nearly 4 times more likely than their non-Hispanic White counterparts to require renal replacement therapy (RRT), with African Americans suffering from the highest rates of ESRD. Despite improvements over the last 25 years, substantial racial differences are persistent in dialysis quality measures such as RRT modality options, dialysis adequacy, anemia, mineral and bone disease, vascular access, and pre-ESRD care. This report will outline the current status of racial disparities in key ESRD quality measures and explore the impact of race. While the term race represents a social construct, its association with health is more complex. Multiple individual and community level social determinants of health are defined by the social positioning of race in the U.S., while biologic differences may reflect distinct epigenetic changes and linkages to ancestral geographic origins. Together, these factors conspire to influence dialysis outcomes among African Americans with ESRD.

Hepcidin serum levels and resistance to recombinant human erythropoietin therapy in hemodialysis patients

OBJECTIVE

The aim of this study was to analyze the factors that are associated with the response to erythropoiesis-stimulating agents (ESAs) and its association with hospitalization and mortality rates; to evaluate the serum hepcidin level and its associations with iron profile, inflammatory markers, ESA responsiveness, and mortality; and to determine independent factors affecting ERI and hepcidin.

MATERIALS AND METHODS

To evaluate a dose-response effect of ESAs we used the erythropoietin resistance index (ERI). Patients were stratified in two groups: nonresponders and responders (ERI>15, n=20, and ERI ≤15U/kg/week/g per 100mL, n=153, respectively). Hematological data, hepcidin levels, iron parameters, inflammatory markers, hospitalization and mortality rates were compared between the groups. Multiple regression analysis was used to determine independent factors affecting ERI and hepcidin.

RESULTS

C-reactive protein (CRP) (β=0.078, P=0.007), albumin (β=-0.436, P=0.004), body mass index (β=-0.374, P<0.001), and hospitalization rate per year (β=3.017, P<0.001) were found to be significant determinants of ERI in maintenance hemodialysis (MHD) patients. Inadequate dialysis was associated with higher ERI. Patients with concomitant oncological diseases had higher ERI (31.2±12.4 vs 9.7±8.1U/kg/week/g per 100mL, P=0.002). The hepcidin level was 158.51±162.57 and 120.65±67.28ng/mL in nonresponders and responders, respectively (P=0.33). Hepcidin correlated directly with ERI, dose of ESAs, ferritin and inversely with Hb, transferrin saturation, and albumin. ERI (β=4.869, P=0.002) and ferritin (β=0.242, P=0.003) were found to be significant determinants of hepcidin in MHD patients. The hospitalization rate per year was 2.35±1.8 and 1.04±1.04 in nonresponders and responders, respectively (P=0.011). The mean length of one hospitalization was 25.12±21.26 and 10.82±17.25 days, respectively (P=0.012). Death occurred in 30% of the patients from the responders' group and in 50% from the nonresponders' group (P=0.289). The mean hepcidin concentration of patients who died was 141.9±129.62ng/mL and who survived, 132.98±109.27ng/mL (P=0.797).

CONCLUSIONS

CRP, albumin, BMI, and hospitalization rate per year were found to be significant determinants of ERI in MHD patients. Inadequate dialysis was associated with higher epoetin requirements. There were no difference in patient mortality by ERI, but a significant difference in hospitalization rates and mean length of one hospitalization was revealed. A significant positive relation between hepcidin and ERI was revealed. ERI and ferritin were found to be significant determinants of hepcidin in MHD patients. Hepcidin was not related to mortality.

Variables de la desnutrición en pacientes en diálisis

Introducción: El paciente en diálisis va a sufrir una desnutrición proteico-calórica, con diferentes factores implicados en su aparición, lo cual se asocia con una elevadísima morbilidad cardiovascular y mortalidad. Se ha estimado una prevalencia de desnutrición en la población en hemodiálisis del 18-75%, siendo por tanto, un problema de especial relevancia en este tipo de pacientes. Objetivo: Realizar una revisión bibliográfica de los artículos científicos existentes sobre las variables que intervienen en la desnutrición del paciente en diálisis. Metodología: Se ha realizado una revisión bibliográfica mediante las bases de datos PubMed, Scielo, Pro- Quest. La búsqueda se ha realizado con términos Mesh, con una antigüedad no mayor de 5 años y con distintas palabras clave. Resultados: Se han revisado 19 artículos. La mayoría de los artículos fueron estudios observacionales y de revisión. Los factores que se asocian con desnutrición son la edad, pérdida de masa muscular, baja actividad física y dieta pobre en micronutrientes. Otro factor muy importante, es la inflamación. En cuanto a los métodos diagnósticos, son variados y diferentes, debido a la gran cantidad de variables que influyen en la desnutrición. Conclusiones: La desnutrición en pacientes en diálisis depende de distintas variables y no solamente de la dieta. Los factores que se asocian con desnutrición son mayor edad, pérdida de masa muscular, baja actividad física y dieta pobre en micronutrientes. Además, habría que añadir el doble papel que juega la inflamación en este proceso, pues puede ser tanto consecuencia como factor predisponente a la desnutrición.

Nutrition, vitamin D, and health outcomes in hemodialysis: time for a feeding frenzy?

PURPOSE OF REVIEW

The role of nutrition and nutritional supplementation in dialysis recently has been reinvigorated, with small clinical trials exploring surrogate outcomes and larger epidemiologic studies generating treatment hypotheses requiring further study. The present review focuses on major aspects of nutrition and outcomes in hemodialysis patients: protein and calorie intake and nutritional vitamin D supplementation.

RECENT FINDINGS

Building on data from small studies, two large, quasi-experimental cohort studies showed significant mortality benefits associated with oral nutritional supplements provided during dialysis, suggesting potential options for ameliorating the protein-energy wasting that is common in dialysis patients and associated with poor outcomes. Multiple cohort studies suggest, both in the general population and in dialysis, that higher 25(OH) vitamin D levels are associated with improved outcomes; however, no major mortality trials exist in dialysis, and the smaller, surrogate studies conducted to date have been disappointing, showing no consistent benefits in surrogate outcomes including inflammation and anemia, despite appropriate responses of vitamin D levels to repletion.

SUMMARY

Nutritional interventions are attractive options for improving outcomes in dialysis patients. Nutritional protein supplements have considerable promise, but require further study, preferably in a large, generalizable pragmatic trial. Small nutritional vitamin D supplementation trials in dialysis have had disappointing results. In the absence of new data, there appears to be no role for routine assessment or repletion of 25(OH) vitamin D deficiency or insufficiency in dialysis.

A Prospective Multicenter Randomized Controlled Study on Interleukin-6 Removal and Induction by a new Hemodialyzer With Improved Biocompatibility in Hemodialysis Patients: A Pilot Study

We compared interleukin-6 (IL-6) removal and induction between conventional polysulfone (Con) and TORAYLIGHT NV (NV) dialyzers in hemodialysis patients. Twenty patients on Con with high IL-6 concentrations (2.7-8.5 pg/mL) were randomized to Con or NV group. Dialyzer performance was determined in NV group while patients were on Con and after being switched onto NV. Erythropoiesis-stimulating agent (ESA) response index (ERI) was assessed every 4 months for one year. IL-6 clearance was comparable between Con and NV. IL-6 removal rates were comparable for the first 1 h, but were higher with NV for the entire session (P = 0.03). Before-to-during-dialysis IL-6 concentration ratios were lower with NV on the venous side after the session (P = 0.03). During the one-year study, hemoglobin was lower in Con group than in NV group at month 8 (P = 0.046). ERI decreased in NV and increased in Con group, with a significant difference between the groups (P = 0.002). NV and Con are comparable in removing IL-6 and both induce IL-6. However, the data suggest that NV induces less IL-6, which may reduce the risk of ESA hyporesponsiveness.

Association of dental and periodontal disease with chronic kidney disease in patients of a single, tertiary care centre in Thailand

BACKGROUND

Several studies have shown an association between oral diseases and chronic kidney disease (CKD), and regular oral care may be an important strategy for reducing the burden of CKD. The objective of this study was therefore to evaluate the association between dental and periodontal diseases in Thai patients with various stages of CKD.

METHODS

This was designed as a cross-sectional study and was performed between 2011 and 2012. The inclusion criteria were age >20 years and a diagnosis of CKD for at least 90 days. Data from medical records were collected, clinical oral examination was performed, and data were statistically analysed.

RESULTS

A total of 129 patients with different stages of CKD were included. Ninety-eight (76%) were men. The age range was 30-86 years. The Decay, Missing and Filling Tooth Index and the number of missing teeth were higher in the group with moderate CKD than in the control group (21 vs 17.5, p=0.045, 13 vs 8 p=0.01, respectively). Serum albumin levels decreased when estimated glomerular filtration rate (eGFR) was in decline (γ=0.33; p=0.002). Severe periodontitis was significantly higher in the 'more severe CKD group' (eGFR <60 mL/min/1.73 m(2)) than in the 'less severe CKD group' (eGFR 60-90 mL/min/1.73 m(2); 24% vs 9%, p=0.03). Severe periodontitis, eGFR <30 mL/min/1.73 m(2) and brushing teeth more than once a day were associated with hypoalbuminaemia (defined as <3.8 g/dL) (OR (95% CI) 5.88 (1.64 to 21.11), 5.80 (1.58 to 21.35) and 0.16 (0.05 to 0.60), respectively).

CONCLUSIONS

Severe periodontal diseases were more prevalent in patients with more severe CKD than in those with less severe CKD. The novel association of serum albumin levels with periodontal status was demonstrated in progressive stages of CKD. Dental intervention may be beneficial from the early stages of CKD.

Association of Erythropoietin Resistance with Fatigue in Hemodialysis Patients: A Cross-Sectional Study

BACKGROUND/AIMS

Fatigue is a common symptom in patients receiving hemodialysis (HD) and is generally associated with anemia. However, it can be difficult to resolve, even when anemia has been treated using erythropoiesis-stimulating agents and iron replacement therapy. In the present study, we examined the associations of anemia, the erythropoietin resistance index (ERI) and iron deficiency with fatigue during HD.

METHODS

In this cross-sectional study, fatigue score was calculated on the basis of questionnaire responses in HD patients. Participants were divided into 3 groups according to their hemoglobin (Hb) levels (low, normal and high). Iron deficiency was assessed as a transferrin saturation (TSAT) of <20%.

RESULTS

We included 571 HD patients (men/women 368/203; mean age 62.2 ± 10.8 years). Among the 3 groups, fatigue scores increased significantly with decreasing Hb levels. HD patients with low Hb levels (<90 g/l) had significantly higher fatigue scores than those with higher Hb levels (≥120 g/l). In the multiple regression analysis, we showed that a high ERI (β = 0.208) and a low TSAT (β = -0.155), but not the Hb level, were significantly associated with increased fatigue score. Moreover, this was independent of age, gender and modifiable confounders linked to anemia. Even after restricting patients to those without iron deficiency (TSAT ≥20%), the ERI (β = 0.258) retained a significant and independent association with the fatigue score.

CONCLUSION

Iron deficiency and a high ERI despite iron sufficiency may cause fatigue in HD patients.

High Ferritin Level and Malnutrition Predict High Risk of Infection-Related Hospitalization in Incident Dialysis Patients: A Japanese Prospective Cohort Study

AIMS

The aim of the study was to clarify the relationship between serum ferritin and infectious risks.

METHODS

We evaluated all hospital admissions due to infections, clinical biomarkers and nutrition status in 129 incident Japanese dialysis patients during a median follow-up of 38 months.

RESULTS

Kaplan-Meier analysis revealed that the period without infections requiring hospitalization was significantly shorter in ferritin > median (82.0 ng/ml) group than in the ferritin < median group (log-rank test 4.44, p = 0.035). High ferritin was associated with significantly increased relative risk of hospitalization for infection (Cox hazard model 1.52, 95% CI 1.06-2.17). The number of hospitalization days was gradually longer in patients with high ferritin levels and malnutrition.

CONCLUSION

Although serum ferritin levels were low, and doses of iron administered to dialysis patients in Japan are generally lower than in Western countries, an elevated ferritin level was associated with increased risk of infection, particularly in patients with poor nutritional status.

The Prognostic Value of High-sensitivity C-reactive Protein and Prealbumin for Short-term Mortality in Acutely Hospitalized Multimorbid Elderly Patients: A Prospective Cohort Study

OBJECTIVES

To establish the predictive value on mortality after 2 months from hospital admission of two laboratory markers of nutritional and inflammatory status, high-sensitivity C-reactive protein (hs-CRP) and prealbumin, in a cohort of frail multimorbid elderly without terminal illness.

DESIGN

Prospective cohort study.

SETTING

Internal medicine ward of a large teaching hospital in Italy.

PARTICIPANTS

544 Caucasian patients with acute disease consecutively admitted from January to June 2013. 102 were excluded for being younger than 65 years old, having life expectancy <30 days or not having frailty syndrome. Further 42 patients were excluded for missing data or withdrawn at follow-up. Final analysis was performed on 400 subjects (179 M, 221 F, mean age 79±10).

MEASUREMENTS

Serum prealbumin and hs-CRP were measured at admission. Death within 2 months from hospital admission was assessed through a telephonic interview with the caregiver for each patient discharged alive. Inhospital mortality was also recorded. Survival was calculated from date of admission to our unit.

RESULTS

Mean prealbumin at admission was 17.3±7.7 mg/dl, while hs-CRP median was 24.2 mg/L (IQR 8.7 to 51.8). 108 patients (27%) died within two months from admission. In an age- and sex-adjusted analysis, log(hs-CRP) levels at admission, but not prealbumin, were independently associated with an increased risk for mortality (HR 1.40, 95% CI 1.18 to 1.66, p<0.001). After multiple adjustments for covariates, including comorbidity burden measured through Charlson score, log(hs-CRP) remained significantly associated with mortality (HR 1.38, 95% CI 1.08 to 1.76, p=0.01). A Receiver Operating Characteristic (ROC) curve was performed to test the predictive value of hs-CRP at admission on two-month mortality (AUC 0.68, 95% CI 0.63 to 0.72, p<0.001). Cut-off value was set at 38.4 mg/L. After dichotomization of hs-CRP values according to this cut-off, hs-CRP≥38.4 mg/L at admission proved to be a significant risk factor for mortality (HR 2.10, 95% CI 1.23 to 3.58, p=0.006).

CONCLUSION

Serum hs-CRP, but not prealbumin, values at admission are predictors of short-term mortality at hospital admission in elderly multimorbid patients. Inflammation seems to affect prognosis more than malnutrition in this setting and may therefore guide clinicians' attitude towards therapeutic choices.

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

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

Factors Contributing to Erythropoietin Hyporesponsiveness in Patients on Long-Term Continuous Ambulatory Peritoneal Dialysis: A Cross-Sectional Study

BACKGROUND

Factors contributing to erythropoietin (EPO) hyporesponsiveness in patients on long-term continuous ambulatory peritoneal dialysis are not well understood. Therefore, we investigated the factors contributing to EPO hyporesponsiveness using the EPO resistance index (ERI).

METHODS

A total of 14 patients (7 males and 7 females, age 65.0 ± 11.9 years) were selected for this study. We defined ERI as the weekly dose of EPO per body weight divided by hemoglobin (U/kg/g/dl/week). Bioelectrical impedance analysis was used to assess the patients' body composition and fluid status. We examined associations between ERI and clinical parameters, such as physiological, chemical and nutrition status, by correlation and multiple linear regression analyses.

RESULTS

Peritoneal dialysis duration was 95 ± 23 months, and all patients underwent peritoneal dialysis for >5 years. Hemoglobin, blood pressure and ultrafiltration volume of peritoneal dialysis were 11.5 ± 1.2 g/dl, 123 ± 14/72 ± 8 mm Hg and 834 ± 317 ml/day, respectively. Renal Kt/V and peritoneal Kt/V, which are indices of dialysis adequacy, were 0.32 ± 0.31 and 1.70 ± 0.31, respectively. Age and extracellular water/total body water (ECW/TBW) ratio had significant positive correlations with ERI (both p < 0.05). Levels of C-reactive protein, serum albumin, parathyroid hormone and normalized protein catabolic rate were not significantly correlated with ERI. In a multiple regression analysis, ECW/TBW was independently associated with ERI (p < 0.05).

CONCLUSIONS

This study demonstrates that ECW/TBW was a factor contributing to ERI and that appropriate maintenance of body fluid volume could contribute to low EPO dosing.

How the Target Hemoglobin of Renal Anemia Should Be

Renal anemia is caused by the deficiency of endogenous erythropoietin (Epo) due to renal dysfunction. We think that it is possible to slow the progression of chronic kidney disease (CKD) in case we initiate Epo early in pre-dialysis patients, especially in the non-diabetic population. Erythropoiesis stimulating agent (ESA) treatments targeting mild anemia (10-12 g/dl) can decrease the risk of occurrence of cardiovascular disease (CVD) in patients with hypertension, diabetes mellitus and congestive heart failure. As the large randomized controlled trials such as Cardiovascular Risk Reduction by Early Anemia Treatment with Epoetin Beta, Correction of Hemoglobin and Outcomes in Renal Insufficiency and Trial to Reduce Cardiovascular Events with Aranesp Thearpy in the Western countries suggested, we do not recommend high doses of ESA to achieve the target hemoglobin (Hb) level. The target Hb of >13 g/dl might lead to increase in the risk of CVD although maintaining a high Hb of >12 g/dl without ESA is not harmful for CKD patients. It is desirable to determine the target Hb in dialysis patients depending on their ages. Renal anemia should be monitored constantly to start ESA and iron replacement therapy at an appropriate time, while avoiding their excess in order to minimize the occurrence of CVD and other complications. Taken all the international guidelines and our clinical experiences together, we should consider administration of ESA when the Hb level becomes <11 g/dl in pre-dialysis patients and <10 g/dl in dialysis patients.

Minor Elevation in C-Reactive Protein Levels Predicts Incidence of Erythropoiesis-Stimulating Agent Hyporesponsiveness among Hemodialysis Patients

BACKGROUND

Hemodialysis (HD) patients occasionally experience minor asymptomatic elevation in C-reactive protein (CRP) levels, which may be associated with difficulty in managing renal anemia using erythropoiesis-stimulating agents (ESAs). Here, we assessed whether elevation of CRP predicts future incidences of ESA hyporesponsiveness.

METHODS

A total of 2,956 HD patients lacking ESA hyporesponsiveness and infectious diseases were enrolled, and the association between CRP levels and incidence of ESA hyporesponsiveness was assessed. CRP levels were divided into 4 categories (normal [<1.0 mg/l], mild [1.0 ≤ CRP <3.0 mg/l], moderate [3.0 ≤ CRP <10.0 mg/l] and high [≥ 10.0 mg/l]). The primary outcome was the cumulative incidence of ESA hyporesponsiveness, defined as a failure to achieve hemoglobin level ≥ 10 g/dl despite receiving high doses of ESAs (≥ 9,000 U/week recombinant human epoetin [rHuEPO]-α or rHuEPO-β and ≥ 60 μg/week darbepoetin-α) during 12 months of follow-up.

RESULTS

The cumulative incidence of ESA hyporesponsiveness was 134 (4.8%) occurrences over 4 months and 300 (12.4%) over 12 months. The elevated CRP groups had significantly higher incidence of ESA hyporesponsiveness over 4 months of follow-up than the normal reference group (adjusted relative risk [RR] 1.6, 95% CI 1.0-2.6 for moderate; adjusted RR 2.5, 95% CI 1.5-4.1 for high). Furthermore, the association remained consistent even over 12 months (adjusted RR 1.4, 95% CI 1.0-1.8 for moderate; adjusted RR 1.6, 95% CI 1.1-2.4 for high).

CONCLUSIONS

Elevated CRP levels were associated with future incidence of ESA hyporesponsiveness from low-grade inflammation (3.0 ≤ CRP <10.0 mg/l).

Pre-Transplant Erythropoiesis-Stimulating Agent Hypo-Responsiveness and Post-Transplant Anemia

BACKGROUND

At the time of kidney transplantation (KT), almost all patients have anemia caused by low levels of endogenous erythropoietin (EPO), along with several other factors. After KT, anemia improves because of secretion of EPO from the allograft. But some recipients have persistent anemia. Whether or not erythropoiesis-stimulating agent (ESA) hypo-responsiveness before KT affects post-transplant anemia (PTA) remains unknown.

METHODS

Sixty-eight patients received KT between January 2007 and July 2012 through the Department of Urology at Kobe University Hospital, and 35 of these patients were enrolled. Exclusion criteria included age <18 years, unknown ESA dosage at transplantation, ESA start within 1 year after transplantation, and other criteria. We evaluated post-transplant hemoglobin (Hb) levels from the pre-transplant ESA responsive index (ERI): pre-transplant ESA dosage/Hb × body weight at 1 year after transplantation.

RESULTS

The mean (± SD) Hb of all patients rose from 11.3 ± 1.0 mg/dL to 12.7 ± 1.4 mg/dL at 1 year after transplantation (P < .01). The pre-transplant low ERI group (<10) showed significantly higher hemoglobin levels compared with the pre-transplant high ERI group (≥ 10; 12.9 ± 1.14 mg/dL versus 11.8 ± 1.76 mg/dL, respectively; P = .03).

CONCLUSIONS

ESA hypo-responsiveness before KT carried over after KT. Low pre-transplant ERI might be a sentinel marker for PTA.

Efficacy of losartan for improving insulin resistance and vascular remodeling in hemodialysis patients

Insulin resistance and vascular remodeling are prevalent and predict cardiovascular mortality in hemodialysis patients. Angiotensin II (Ang II) may be involved in both pathogenesis. In the present study, we investigated the effects of the Ang II receptor blocker losartan on insulin resistance, arterial stiffness, and carotid artery structure in hemodialysis patients. Seventy-two hemodialysis patients were randomly assigned to receive either losartan 50 mg qd (n = 36) or β-blocker bisoprolol 5 mg qd (n = 36). At the start and at month 12, ambulatory blood pressure (BP) monitoring, aortic pulse wave velocity (PWV) measurements, and carotid artery ultrasound were performed, and homeostasis model assessment index of insulin resistance (HOMA-IR) was determined. During the study period, bioimpedance method was used to evaluate volume status every 3 months. Home-monitored BPs were measured at least monthly. Ambulatory BP decreased significantly and similarly by either losartan or bisoprolol. Decreases in PWVs in losartan group at the end of month 12 were significantly greater than changes in PWV in bisoprolol group (0.9 ± 0.3 vs. 0.4 ± 0.5 m/s, P = 0.021). Common carotid artery intima-media cross-sectional area decreased significantly only in patients treated with losartan (20.3 ± 4.9 vs. 19.1 ± 5.1 mm(2) , P = 0.001), and HOMA-IR was also reduced in losartan group only (1.9 ± 1.0 vs. 1.7 ± 0.8, P = 0.003). Multiple regression analysis showed significant correlations between changes in PWV and changes in HOMA-IR. With comparable BP-lowering efficacy, losartan achieved better improvement in insulin sensitivity, arterial stiffness, and carotid artery hypertrophy in hemodialysis patients. The regression of arterial stiffness may be in part through attenuation in insulin resistance.

Association of plasma F2-isoprostanes and isofurans concentrations with erythropoiesis-stimulating agent resistance in maintenance hemodialysis patients

Background

In patients undergoing maintenance hemodialysis (HD), hyporesponsiveness to erythropoiesis stimulating agents (ESAs) is associated with adverse clinical outcomes. Systemic inflammation is highly prevalent in HD patients and is associated with ESA hyporesponsiveness. Oxidative stress is also highly prevalent in HD patients, but no previous study has determined its association with ESA response. This study assessed the association of plasma markers of oxidative stress and inflammation with ESA resistance in patients undergoing maintenance HD.

Methods

We analyzed data from 165 patients enrolled in the Provision of Antioxidant Therapy in Hemodialysis study, a randomized controlled trial evaluating antioxidant therapy in prevalent HD patients. Linear and mixed-effects regression were used to assess the association of baseline and time-averaged high sensitivity F2-isoprostanes, isofurans, C-reactive protein (hsCRP), and interleukin-6 (IL-6) with ESA resistance index (ERI), defined as the weekly weight-adjusted ESA dose divided by blood hemoglobin level. Unadjusted models as well as models adjusted for potential confounders were examined. Predicted changes in ERI per month over study follow-up among baseline biomarker quartiles were also assessed.

Results

Patients with time-averaged isofurans in the highest quartile had higher adjusted mean ERI compared with patients in the lowest quartile (β = 14.9 ng/ml; 95 % CI 7.70, 22.2; reference group <0.26 ng/ml). The highest quartiles of hsCRP and IL-6 were also associated with higher adjusted mean ERI (β = 10.8 mg/l; 95 % CI 3.52, 18.1 for hsCRP; β = 10.2 pg/ml; 95 % CI 2.98, 17.5 for IL-6). No significant association of F2-isoprostanes concentrations with ERI was observed. Analyses restricted to baseline exposures and ERI showed similar results. Baseline hsCRP, IL-6, and isofurans concentrations in the highest quartiles were associated with greater predicted change in ERI over study follow-up compared to the lowest quartiles (P = 0.008, P = 0.004, and P = 0.04, respectively). There was no association between baseline F2-isoprostanes quartile and change in ERI.

Conclusions

In conclusion, higher concentrations of isofurans, hsCRP and IL-6, but not F2-isoprostanes, were associated with greater resistance to ESAs in prevalent HD patients. Further research is needed to test whether interventions that successfully decrease oxidative stress and inflammation in patients undergoing maintenance HD improve ESA responsiveness.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0074-9) contains supplementary material, which is available to authorized users.