Clinical significance of a novel reticulocyte-based erythropoietin resistance index in HD patients: A retrospective study.

INTRODUCTION: The erythropoietin resistance index (ERI) is an indicator of erythropoiesis-stimulating agent (ESA) responsiveness and is typically calculated using Hb. However, Hb does not directly reflect ESA-induced erythropoiesis because of its long-term nature. We thus designed a novel ERI calculated with reticulocyte Hb (RetHb), a real-time index, and investigated its association with mortality in HD patients. METHODS: We calculated the ERI using the change in RetHb before and after ESA administration (ERIΔRetHb ) and retrospectively analyzed its association with 3-year all-cause mortality using Kaplan-Meier survival curves and Cox regression analyses. RESULTS: A total of 102 patients were included. Patients with the highest ERIΔRetHb had the worst prognosis according to the Kaplan-Meier survival curves (Log-rank p = 0.02). Multivariate Cox regression analysis showed that the ERIΔRetHb was significantly and independently associated with all-cause mortality (hazard ratio: 9.82, 95% CI [1.50, 64.41], p = 0.02). CONCLUSION: The ERIΔRetHb was significantly and independently associated with all-cause mortality in HD patients.

Potential effective treatment of shortening continuous erythropoietin receptor activator treatment interval combined with iron supplementation in hemodialysis patients.

Our previous randomized controlled trial comparing the total dose of weekly versus biweekly continuous erythropoietin receptor activator (CERA) therapy to maintain optimal hemoglobin (Hb) levels showed no significant differences between the two therapies. This post-hoc analysis assessed whether the total dose of weekly versus biweekly CERA therapy to maintain Hb levels among HD patients differed among groups with or without iron supplementation. Of 107 patients, 40 received intravenous iron supplementation due to iron deficiency (iron group) and 67 did not (non-iron group). In the iron group, the weekly therapy tended to require a lower total CERA dose compared with the biweekly therapy (274 ± 274 vs 381 ± 223 µg/12 weeks, P = 0.051). Changes in circulating hepcidin levels, a negative regulator of intestinal iron uptake, after 2 weeks of CERA treatment were significantly lower in the weekly therapy compared with the biweekly therapy (-4.2 ± 6.3 vs 11.1 ± 7.3 ng/mL, P = 0.015). In the non-iron group, there were no significant differences in total CERA dose or changes in hepcidin levels between the two therapies. Shortening the CERA treatment interval combined with iron supplementation may lead to the more efficient treatment of HD patients with iron deficiency.

Comparison of the effects of weekly and biweekly intravenous CERA administration on erythropoiesis: A randomized controlled trial.

Although continuous erythropoietin receptor activators (CERAs) are widely used erythropoiesis-stimulating agents for correcting renal anemia in patients undergoing hemodialysis (HD), few reports have examined weekly CERA administration. In this randomized controlled trial, we compared the efficacy and changes in the parameters of iron metabolism and erythropoiesis between weekly and biweekly CERA administration. In total, 120 patients undergoing maintenance HD were randomized to the weekly or biweekly group. The primary end point was the total CERA dose needed to maintain the target hemoglobin (Hb) levels during a 12-week evaluation period. There was no significant difference in the total dose between the weekly and biweekly groups (median 175.0 [interquartile range (IQR) 93.8-337.5] µg/12 weeks vs. 300.0 [IQR 125.0-375.0] µg/12 weeks, P = .18). The mean Hb levels during the evaluation period were 10.9 ± 0.8 g/dL in the weekly group and 10.7 ± 0.8 g/dL in the biweekly group (P = .25). Weekly CERA administration was well tolerated. Weekly CERA administration similarly managed anemia as biweekly administration in patients undergoing HD.

Effects of Rikkunshito treatment on renal fibrosis/inflammation and body weight reduction in a unilateral ureteral obstruction model in mice.

Chronic kidney disease (CKD) progresses to end-stage renal failure via renal tubulointerstitial fibrosis. Malnutrition, inflammation, and arteriosclerosis interact to exacerbate the poor prognosis of CKD, and their effective management is thus essential. The traditional Japanese medicine Rikkunshito (RKT) exerts appetite-stimulating effects via ghrelin, which attenuates inflammation and fibrosis. We evaluated the therapeutic effect of RKT in unilateral ureter obstruction (UUO)-induced renal fibrosis/inflammation and body weight loss in mice. UUO and sham-operated mice were fed a standard diet or diet containing 3.0% RKT. Renal fibrosis was investigated by histopathology and macrophage infiltration was determined by immunohistochemistry. Expression levels of genes associated with fibrosis, inflammation, ghrelin, and mitochondrial function were determined by quantitative reverse transcription-polymerase chain reaction and western blot analyses. RKT treatment partially prevented UUO-induced weight loss but failed to attenuate renal fibrosis and inflammation. Renal expression of sirtuin 1, a ghrelin-downstream signalling molecule, and gene expression of peroxisome proliferator-activated receptor-γ coactivator 1α and Bcl-2/adenovirus E1B interacting protein 3 were unaffected by RKT. These results indicate that RKT inhibits weight loss but does not improve renal fibrosis or inflammation in a rapidly progressive renal fibrosis mouse model. RKT may have a protective effect on weight loss associated with CKD.

Plasma Cystine Levels and Cardiovascular and All-Cause Mortality in Hemodialysis Patients.

Oxidative stress accelerates the development of cardiovascular disease. Plasma cystine, a thiol oxidative stress marker, is related to several established factors for cardiovascular disease risk and prognosis. Although a comprehensive oxidative stress index is clinically required for hemodialysis patients with high oxidative stress, there are few reports concerning thiol oxidative stress markers predicting their prognosis. We investigated the relationship between plasma amino acids including cystine levels and cardiovascular disease-related and all-cause mortality in 132 maintenance hemodialysis patients. Higher cystine levels were associated with old age, longer hemodialysis duration, hemodialysis-associated hypotension, higher cardiothoracic ratio, higher blood urea nitrogen, and lower ankle-brachial index. Multivariate Cox regression analysis revealed that high plasma cystine was independently related with both cardiovascular disease mortality and all-cause mortality. Thus, high plasma cystine levels predict the prognosis of hemodialysis patients. High cystine levels necessitate a careful investigation for the cause of oxidative stress and comorbidities like vascular injury.

CPT-11-Induced Delayed Diarrhea Develops via Reduced Aquaporin-3 Expression in the Colon.

While irinotecan (CPT-11) has a potent anti-cancer effect, it also causes serious diarrhea as an adverse reaction. In this study, we analyzed the pathogenic mechanism of CPT-11-induced delayed diarrhea by focusing on water channel aquaporin-3 (AQP3) in the colon. When rats received CPT-11, the expression level of AQP3 was reduced during severe diarrhea. It was found that the expression levels of inflammatory cytokines and the loss of crypt cells were increased in the colon when CPT-11 was administered. When celecoxib, an anti-inflammatory drug, was concomitantly administered, both the diarrhea and the reduced expression of AQP3 induced by CPT-11 were suppressed. The inflammation in the rat colon during diarrhea was caused via activated macrophage by CPT-11. These results showed that when CPT-11 is administered, the expression level of AQP3 in the colon is reduced, resulting in delayed diarrhea by preventing water transport from the intestinal tract. It was also suggested that the reduced expression of AQP3 might be due to the inflammation that occurs following the loss of colonic crypt cells and to the damage caused by the direct activation of macrophages by CPT-11. Therefore, it was considered that anti-inflammatory drugs that suppress the reduction of AQP3 expression could prevent CPT-11-induced delayed diarrhea.

Acceleration of iron utilization after intravenous iron administration during activated erythropoiesis in hemodialysis patients: a randomized study.

This study aimed to evaluate the effect of different timings of iron administration during erythropoiesis activated by continuous erythropoietin receptor activator (CERA) on reticulocyte iron uptake in hemodialysis patients. In total, 110 patients were randomized to receive 40 mg intravenous elemental iron doses at all three hemodialysis sessions in the first week (IW1 group: n = 57) or in the third week (IW3 group: n = 53) after CERA administration. Following CERA administration at day 0, reticulocyte count increased, peaking at day 7. At days 7 and 14, the observed changes in Ret-He were higher in the IW1 group than in the IW3 group. Increases in total reticulocyte hemoglobin at day 7 were higher in the IW1 group than in the IW3 group. In contrast, there was only tendency toward greater total reticulocyte hemoglobin after iron administration in the third week in the IW3 group. Intravenous iron supplementation in the first week of CERA administration increases reticulocyte iron uptake; however, iron supplementation in the third week does not. The findings indicate that iron should be intravenously administered to increase the efficacy of CERA within 1 week of CERA administration during highly active erythropoiesis.

Changes in hepcidin and reticulocyte hemoglobin equivalent levels in response to continuous erythropoietin receptor activator administration in hemodialysis patients: a randomized study.

Inadequate iron availability limits the response to erythropoiesis-stimulating agents (ESA) and hepcidin is a key regulator of iron metabolism. However, there is little information concerning time-dependent changes in hepcidin in response to the change of accelerated iron demand due to ESA-induced erythropoiesis. In this study, iron-related parameters, including hepcidin levels, were explored in comparison to patients receiving continuous erythropoietin receptor activator (CERA) and epoetin beta (EPO) treatment. Ninety-four patients were randomized to receive monthly CERA (N = 47) or EPO three times/week (N = 47). After the titration period, hemoglobin levels and iron-related parameters were examined. Data for 71 patients were evaluated (CERA, N = 34; EPO, N = 37). Compared with EPO treatment, CERA treatment caused significant decreases within 1 week in hepcidin (-93.5 ± 46.9 vs. -1.3 ± 38.3 ng/mL, P < 0.01), reticulocyte hemoglobin equivalent (Ret-He) (-4.03 ± 2.64 vs. -1.13 ± 1.41 pg, P < 0.01), ferritin (-58.9 ± 30.5 vs. -12.2 ± 23.8 ng/mL, P < 0.01) and transferrin saturation (-13.2 ± 9.1 vs. 1.0 ± 11.9%, P < 0.01) and significant increases within 2 weeks in the levels of hemoglobin (0.42 ± 0.38 vs. -0.02 ± 0.48 g/dL, P < 0.01). In conclusion, hepcidin, Ret-He, ferritin and transferrin saturation levels decreased within 1 week and hemoglobin increased within 2 weeks after CERA administration. Time course of iron-related parameters including hepcidin demonstrated accelerated iron utilization appropriately according to ESA-induced erythropoiesis.

Loss of amino acids into dialysate during hemodialysis using hydrophilic and nonhydrophilic polyester-polymer alloy and polyacrylonitrile membrane dialyzers.

During hemodialysis, amino acid loss through the dialysate remained a significant problem and was not clear in some dialyzers; therefore, we investigated amino acid loss with hydrophilic and nonhydrophilic polyester-polymer alloy membranes and polyacrylonitrile membranes. Nine maintenance hemodialysis patients were studied to assess amino acid loss during hemodialysis with the three membranes. Total amino acid losses were 85.7 ± 27.2 mg/L, 83.3 ± 16.1 mg/L, and 72.1 ± 22.5 mg/L with the hydrophilic, nonhydrophilic polyester-polymer alloy, and polyacrylonitrile membranes, respectively. Amino acid losses were greater with the hydrophilic membrane compared with the polyacrylonitrile membrane for ornithine (2.0 ± 0.6 vs. 1.4 ± 0.4 mg/L, P = 0.025), phenylalanine (2.4 ± 0.9 vs. 1.8 ± 0.8 mg/L, P = 0.012), and tryptophan (0.6 ± 0.2 vs. 0.4 ± 0.2 mg/L, P = 0.023). Amino acid losses were greater with the nonhydrophilic membrane than with the polyacrylonitrile membrane for ornithine (2.0 ± 0.4 vs. 1.4 ± 0.4 mg/L, P = 0.017), phenylalanine (2.3 ± 0.5 vs. 1.8 ± 0.8 mg/L, P = 0.018), tryptophan (0.7 ± 0.2 vs. 0.4 ± 0.2 mg/L, P = 0.003), and cystine (3.2 ± 0.7 vs. 2.0 ± 0.7 mg/L, P = 0.005). In conclusion, greater losses of ornithine, phenylalanine, tryptophan, and cystine were observed with polyester-polymer alloy than with polyacrylonitrile membranes during hemodialysis. Constant attention should be paid to the amino acid loss profile to improve nutritional control in hemodialysis patients.

Time-dependent resistance to erythropoiesis-stimulating agent and mortality in hemodialysis patients in the Japan Dialysis Outcomes and Practice Patterns Study.

BACKGROUND/AIMS: Resistance to erythropoiesis-stimulating agent (ESA) is associated with mortality in hemodialysis (HD) patients. Time-dependent variability of ESA resistance has been not investigated adequately, although consistently high ESA resistance is expected to be a high risk for mortality. Our aim, therefore, was to investigate consistently high ESA resistance as an independent predictor of mortality in HD patients. METHODS: This study evaluated 2,104 Japanese HD patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS) III. ESA resistance index (ERI) was defined as the weekly weight-adjusted dose of ESA divided by hemoglobin concentration. The average ERI was calculated from ERI levels every 4 months throughout the observation period for each patient. To assess the size of the fluctuation in average ERI during the observation periods according to ERI quartiles at the enrollment periods, six patient groups were defined on the basis of patterns of ERI level fluctuation: low-low (Low), intermediate-intermediate (Intermediate), high-high (High), low-intermediate, intermediate-high, and low-high. RESULTS: The number of deaths among the patients was 227 (10.8%), which included 113 (5.4%) cases of cardiovascular disease (CVD). In multivariate analysis after adjustment for age, albumin, C-reactive protein, comorbidities, etc., the High group was independently and significantly related to all-cause and CVD-related mortality (OR = 2.33, 95% CI: 1.33-4.07, p = 0.002, and OR = 2.09, 95% CI: 1.05-4.14, p = 0.035, respectively). CONCLUSION: Factoring out fluctuating ERI increases the ability of consistently high ERI levels as an independent risk factor for all-cause and CVD mortality in HD patients.

Factors related to elevated 24-h blood pressure in young adults.

Variation in 24-h blood pressure (BP) is associated with multiple factors, but the association has not been thoroughly examined in young adults. To elucidate the potential factors associated with variation in 24-h BP, 331 healthy medical students were investigated. Awake mean BP negatively correlated with sleep duration in males. Sixty-seven subjects (20.2%) had a high 24-h BP according to the ESH/ESC 2007 guidelines (systolic blood pressure (SBP) 125 and/or diastolic blood pressure (DBP) 80 mmHg). After multivariate analysis for confounding factors, male gender, body mass index (BMI), smoking, the 24-h low/high frequency component (heart rate variability spectral analysis), and short sleep (5 h or less) were found to be associated with high BP. The present study is the first to demonstrate the multivariate risk factors for elevated 24-h BP in a large number of young adults. Further investigation is required to determine the causal relationship between modifiable BP-related factors and elevated 24-h BP in young adults.