Changes in erythropoiesis-stimulating agent responsiveness after transfer to combined therapy with peritoneal dialysis and hemodialysis for patients on peritoneal dialysis: A prospective multicenter study in Japan.

INTRODUCTION: Inadequate dialysis and fluid overload are corrected after starting combined therapy with peritoneal dialysis (PD) and hemodialysis (HD). However, the effects on anemia management has not been elucidated. METHODS: We conducted a prospective, multicenter, observational cohort study of 40 PD patients (age, 60 ± 10 years; male, 88%; median PD duration, 28 months) starting combined therapy and investigated changes in several clinical parameters, including erythropoiesis-stimulating agent (ESA) resistance index (ERI). RESULTS: ERI decreased significantly during 6 months after switching to combined therapy (from 11.8 [IQR 8.0-20.4] units/week/kg/(g/dL) to 7.8 [IQR 3.9-18.6] units/week/kg/(g/dL), p = 0.047). Body weight, urinary volume, serum creatinine and the dialysate-to-plasma creatinine ratio (D/P Cr) decreased, whereas hemoglobin and serum albumin increased. In subgroup analysis, the changes in ERI were not affected by cause for starting combined therapy, PD holiday and D/P Cr. CONCLUSION: Although detailed mechanism was unclear, ESA responsiveness improved after switching from PD alone to combined therapy.

Clinical feasibility of transfer to combined therapy with peritoneal dialysis and hemodialysis for patients on peritoneal dialysis: A prospective multicenter study in Japan.

INTRODUCTION: Although combined therapy with peritoneal dialysis (PD) and hemodialysis (HD) is widespread in Japan, its clinical utility has been reported only in retrospective or before-and-after test lacking a control group. METHODS: We conducted a prospective, multicenter, observational cohort study of 176 incident PD patients and compared patient survival and changes in clinical parameters between patients on different dialysis modalities. RESULTS: During a median follow-up of 41 months, 47 patients transferred to combined therapy and 35 patients transferred directly to HD. Patients transferred to combined therapy had a significantly better survival than those transferred directly to HD. However, we could not establish this difference in a multivariate analysis because only six patients died among these groups. The decreases in urea nitrogen and serum creatinine were more prominent among patients directly transferred to HD. CONCLUSION: This is the first report revealing clinical feasibility of transfer to combined therapy for PD patients.

Pleiotropic effect of erythropoiesis-stimulating agents on circulating endothelial progenitor cells in dialysis patients.

BACKGROUND: Recent studies have suggested that erythropoiesis-stimulating agents (ESAs) may accelerate not only angiogenesis but also vasculogenesis, beyond erythropoiesis. METHODS: We conducted a 12-week prospective study in 51 dialysis patients; 13 were treated with recombinant human erythropoietin (EPO, 5290.4 ± 586.9 IU/week), 16 with darbepoetin (DA, 42.9 ± 4.3 µg/week), 12 with epoetin ß pegol (CERA, 40.5 ± 4.1 µg/week) and 10 with no ESAs. Vascular mediators comprising endothelial progenitor cells (EPCs), vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP-2), and high-sensitivity C-reactive protein (hs-CRP) were measured at 0 and 12 weeks. EPCs were measured by flow cytometry as CD45lowCD34+CD133+ cells. RESULTS: The EPC count increased significantly to a greater extent in the EPO group than in the other three group, and increased significantly from 0 to 12 weeks in a EPO dose-dependent manner. In both the DA and CERA groups, the EPC count did not change at 12 weeks. Serum levels of VEGF, MMP-2 and hs-CRP were not affected by ESA treatment in all groups. In the CERA group, serum ferritin decreased significantly compared to the no-ESA group and correlated with CERA dose, although use of iron was permitted if required during the prospective study period of 12 weeks. CONCLUSIONS: When patients on dialysis were treated with clinical doses of various ESAs, only EPO induced a significant increase of circulating EPCs from bone marrow, whereas, DA and CERA had no effect.

Modulation of circulating endothelial progenitor cells by erythropoiesis-stimulating agents in patients with chronic kidney disease stage G5 and 5D
.

AIMS: Circulating endothelial progenitor cells (EPCs) play a pivotal role in vasculogenesis and promote angiogenesis by secreting growth factors. Recent studies have suggested that erythropoietin (EPO) may accelerate not only angiogenesis but also vasculogenesis, beyond erythropoiesis. The aim of this study was to investigate whether two erythropoiesis-stimulating agents (ESAs) modulate vascular-related factors and EPC mobilization in patients with chronic kidney disease stage G5 and dialysis (CKD G5 and 5D). MATERIALS AND METHODS: We conducted a 12-week prospective study in 63 patients; 21 patients received recombinant human erythropoietin (rhEPO) (EPO group, 4,565.5 ± 1,994.4 IU/week), 21 patients received darbepoetin (DA) (DA group, 40.1 ± 13.8 µg/week), and 21 patients received no ESAs (no-ESA group). Vascular mediators, including EPCs, vascular endothelial growth factor, matrix metalloproteinase-2 (MMP-2), high-sensitivity C-reactive protein, and asymmetric dimethyl arginine, were measured at 0 and 12 weeks. EPCs were measured by flow cytometry as CD45lowCD34+CD133+ cells. We also performed a subanalysis of dialysis (5D) patients (n = 32) in the three groups. RESULTS: In the EPO group, EPC count increased significantly from 0 to 12 weeks in a dose-dependent manner (r = 0.62, p = 0.005), and the increase was more conspicuous in the subgroup of dialysis 5D patients. In the DA group, the EPC number did not change at 12 weeks. Neither rhEPO nor DA affected the serum levels of the aforementioned biomarkers other than EPC. ;Conclusion: We speculate that the pleiotropic effects of rhEPO and DA beyond their hematopoietic effects may differ between CKD G5 and 5D patients.
.

Establishment and characterization of a novel VEGF-producing HHV-8-unrelated PEL-like lymphoma cell line, OGU1.

Primary effusion lymphoma (PEL) is a rare B-cell lymphoma subtype that is characterized by lymphomatous effusion without the presence of masses, and it typically occurs in human immunodeficiency virus (HIV)-infected individuals. Lymphoma cells are universally positive for human herpesvirus 8 (HHV-8). Recently, a cavity-based effusion lymphoma that is similar to PEL without HHV-8 infection, called HHV-8-unrelated PEL-like lymphoma, has been reported in non-HIV-infected individuals. However, the pathophysiology of this lymphoma is largely undefined. We established a novel B-cell line OGU1 derived from a patient with HHV-8-unrelated PEL-like lymphoma. Notably, OGU1 cells produced vascular endothelial growth factor (VEGF) and expressed VEGF receptor 1, whose inhibitors retarded cell growth. Because VEGF acts as a vascular permeability and growth factor, it could play a role, at least in part, in the pathogenesis of this unique lymphoma. Thus, the OGU1 cell line is useful for the investigation of HHV-8-unrelated PEL-like lymphoma.

Combined therapy with peritoneal dialysis and hemodialysis: a multicenter retrospective observational cohort study in Japan.

BACKGROUND/AIMS: Combining peritoneal dialysis (PD) and hemodialysis (HD) has been common treatment option in Japan. METHODS: In this retrospective, multicenter, observational study, the clinical characteristics and outcomes of 104 patients (57 ± 11 years, males 72%) who had switched from PD alone to combined therapy with PD and HD were studied. Clinical parameters were measured at baseline and after 3 months of combined therapy. RESULTS: At baseline, urine volume, dialysate-to-plasma ratio of creatinine (D/P Cr), and total Kt/V were 150 ml/day (range: 0-2,000 ml/day), 0.67 ± 0.11, and 1.8 ± 0.4, respectively. During the first 3 months of combined therapy, body weight, urine volume, serum creatinine level, and D/P Cr decreased, whereas hemoglobin levels increased. CONCLUSIONS: In patients where PD does not result in acceptable outcomes, combined therapy with PD and HD may have potential benefits in terms of dialysis adequacy and hydration status. Video Journal Club "Cappuccino with Claudio Ronco" at http://www.karger.com/?doi=368389

The Prevalence of the Risk Factors for Atherosclerosis among Type 2 Diabetic Patients Is Greater in the Progressive Stages of Chronic Kidney Disease.

BACKGROUND/AIMS: The prevalence of the risk factors for atherosclerosis, other than diabetes mellitus, among type 2 diabetic patients with different stages of chronic kidney disease (CKD) determined by glomerular filtration rate (GFR) was investigated. METHODS: The prevalence of ten risk factors (age ≥65 years, history of smoking, male gender, obesity, albuminuria, hypertension, hypercholesterolemia, hypo-HDL-cholesterolemia, hyperuricemia and anemia) was determined in 2,107 Japanese type 2 diabetic patients with different stages of CKD (six stages according to GFR). RESULTS: The risk factors for age ≥65 years and male gender were found in 49 and 62% of the study subjects, respectively. The percentages of subjects with a current history of smoking, obesity, albuminuria, hypertension, hypercholesterolemia, hypo-HDL-cholesterolemia, hyperuricemia and anemia were 35, 44, 47, 70, 61, 13, 21 and 26%, respectively. The prevalence of age ≥65 years, male gender, albuminuria, hypertension, hypo-HDL-cholesterolemia, hyperuricemia and anemia was greater in the later stages of GFR, whereas the prevalence of hypercholesterolemia and obesity did not differ between stages. The prevalence of a current history of smoking was lower in the later stages of GFR. The cumulative number of risk factors increased from 3.1 to 6.8 in the later stages of GFR. CONCLUSION: Among type 2 diabetic patients with CKD, the total number of risk factors increases with the progression of renal dysfunction. It is important to pay attention to newly recognized risk factors for hyperuricemia and anemia, in addition to hypertension, albuminuria and hypo-HDL-cholesterolemia, in monitoring diabetic patients with later stages of CKD.

Vildagliptin is Effective for Glycemic Control in Diabetic Patients Undergoing either Hemodialysis or Peritoneal Dialysis.

INTRODUCTION: Vildagliptin can be used in patients with type 2 diabetes mellitus and renal impairment. However, there have been few reports investigating the clinical effectiveness of vildagliptin in diabetic patients undergoing hemodialysis. No previous studies have evaluated the use of vildagliptin in patients undergoing peritoneal dialysis. The authors determined the usefulness of vildagliptin for treating type 2 diabetic patients receiving chronic dialysis, including peritoneal dialysis. METHODS: A retrospective study of ten diabetic patients undergoing peritoneal dialysis and five diabetic patients undergoing hemodialysis who were treated with 50 mg/day of vildagliptin was performed. Clinical parameters were investigated for a period of 6 months starting from the vildagliptin therapy. RESULTS: The hemoglobin A1c (HbA1c) levels were significantly reduced after baseline in both the peritoneal dialysis and hemodialysis groups, whereas the hemoglobin levels did not change during the follow-up period. The mean change in the HbA1c level (ΔHbA1c) was -0.6 ± 0.9% and -0.5 ± 0.7% among the patients undergoing peritoneal dialysis and hemodialysis, respectively. The glycated albumin (GA) levels were also significantly reduced compared with baseline in the peritoneal dialysis group, although the serum albumin levels did not change. The mean change in the GA level (ΔGA) was -3.4 ± 3.1% and -2.1 ± 2.5% among the patients undergoing peritoneal dialysis and hemodialysis, respectively. Stepwise multivariate analyses demonstrated the level of HbA1c at baseline to be significantly associated with the ΔHbA1c and that the level of GA at baseline was significantly associated with the ΔGA. CONCLUSION: Vildagliptin exhibits effectiveness in patients with type 2 diabetes mellitus undergoing peritoneal dialysis or hemodialysis. The degree of improvement in the HbA1c and GA levels was dependent on these levels at baseline, similar to the findings of previous reports of subjects without end-stage kidney disease.

Randomized controlled open-label trial of vitamin E-bonded polysulfone dialyzer and erythropoiesis-stimulating agent response.

BACKGROUND AND OBJECTIVES: A 1-year multicenter prospective randomized controlled study was conducted on the effects of vitamin E-bonded polysulfone dialyzers on erythropoiesis-stimulating agent response in hemodialysis patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Major inclusion criteria were use of high-flux polysulfone dialyzers with 50-70 ml/min ß2-microglobulin clearance over 3 months, transferrin saturation over 20%, same erythropoiesis-stimulating agent for over 3 months, and hemoglobin at 10-12 g/dl. Hemodialysis patients were placed in four interventional groups: two hemoglobin ranges (10.0-10.9 or 11.0-11.9 g/dl) and two dialyzers. Patients were randomly assigned by central registration to a vitamin E-bonded polysulfone dialyzers or polysulfone control group. Primary end point was relative erythropoiesis resistance index at baseline between groups at 12 months. Erythropoiesis resistance index was defined as total weekly erythropoiesis-stimulating agent dose divided by hemoglobin. RESULTS: There were no statistically significant differences in age or sex. There was no significant difference in relative erythropoiesis resistance index between vitamin E-bonded polysulfone dialyzers and control groups at 12 months (vitamin E-bonded polysulfone dialyzers: 1.1, control: 1.3). The vitamin E-bonded polysulfone dialyzers group showed better relative erythropoiesis resistance index than the control group at 11.0-11.9 g/dl hemoglobin (vitamin E-bonded polysulfone dialyzers: 1.0, control: 1.4 at 12 months, significant difference) but no difference at 10.0-10.9 g/dl hemoglobin. CONCLUSIONS: The overall relative erythropoiesis resistance index showed no difference between the vitamin E-bonded polysulfone dialyzers and control groups, although the change in relative erythropoiesis resistance index differed according to hemoglobin level.

Selection guidelines for high-performance membrane.

The fundamental concept for the selection of high-performance membrane is based on solute removal capability and biocompatibility. From this principle, the selection guidelines for high-performance membrane are recommended as follows: (1) The currently available products do not provide coverage of the necessary 'balance between solute removal and biocompatibility' in a single dialyzer for all the dialysis patients. Therefore, it is advisable to choose a high-performance membrane taking into consideration the balance between the solute removal capacity necessary for the patient and the severity of complications that is considered a surrogate marker for biocompatibility. (2) There is an increasing demand in dialysis therapy for new biocompatibility indices such as 'reducing blood pressure variability during dialysis', 'decreasing oxidative stress' and 'delaying the onset or progression of complications'. High-performance membranes developed to address these needs include the ethylene-co-vinyl alcohol copolymer (EVAL) (R) membrane, cellulose triacetate, polymethylmethacrylate, vitamin E-coated polysulfone (PS) membrane, and PS membrane hemodiafiltration filter.

Evaluation of taurine as an osmotic agent for peritoneal dialysis solution.

OBJECTIVE: The development of a glucose-free peritoneal dialysis (PD) solution is important because glucose has been associated with functional and morphological damage to the peritoneal membrane. The ultrafiltration (UF) and biocompatibility of new PD solutions containing taurine (PD-taurine) instead of glucose as an osmolite were tested in a rat PD model. METHODS: To determine the solution's UF ability, different concentrations of taurine in PD solutions were compared to glucose-based PD solutions (PD-glucose) by giving single intraperitoneal injections for 2, 4, and 6 hours. To examine the biocompatibility of PD-taurine, the rats were divided into 3 groups: a 3.86% PD-glucose group, a 3.5% PD-taurine group and a not dialyzed group. The rats were given 10-mL injections of PD fluids intraperitoneally 3 times daily for 7 days. A peritoneal equilibration test (PET) was performed using a 1.9% xylitol solution at the time the rats were sacrificed. Mesothelial cell monolayers were obtained from the animals and studied based on a population analysis. RESULTS: The net UF of PD-taurine increased in a dose-dependent manner; the 3.5% PD-taurine solution was equivalent to the 3.86% PD-glucose solution after 4 hours. The PET showed that the drainage volume and the D(4)/D(0) ratio for xylitol after 4 hours with PD-taurine solution were significantly greater than with the PD-glucose solution (p < 0.001 and p < 0.001 respectively). Mesothelial and fibroblast-like cell proliferation was significantly less with PD-taurine than with PD-glucose (p < 0.01). CONCLUSIONS: These results indicate that PD-taurine resulted in net UF equivalent to that of PD-glucose and was more biocompatible than PD-glucose with respect to the peritoneal membrane.

Losartan elevates the serum high-molecular weight-adiponectin isoform and concurrently improves insulin sensitivity in patients with impaired glucose metabolism.

Adiponectin is an adipocyte hormone that ameliorates insulin resistance and prevents diabetes. Patients with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) are at a high risk of developing diabetes and cardiovascular diseases. Since treatment with angiotensin II receptor blockers retards the development of diabetes, the effects of losartan on serum adiponectin levels were examined with regard to insulin sensitivity in pre-diabetic patients. Sixty-five patients with IFG/IGT (42 males, 23 females, 63+/-13 years old) were randomized to receive 25-100 mg of losartan (n=33) or a calcium channel blocker (CCB, n=32) for 3 months. Before and after the treatment, changes in blood pressure, insulin sensitivity (HOMA-R) and serum concentrations of high molecular weight (HMW)-adiponectin and free fatty acid (FFA) were assessed. At baseline, the HMW-adiponectin concentration negatively correlated with the patient's body mass index, HOMA-R and triglyceride levels, and positively correlated with high-density lipoprotein (HDL)-cholesterol levels. However, the HMW-adiponectin concentration showed no correlation with blood pressure. HMW-adiponectin concentrations were similar between the losartan group and the CCB group. Both the losartan and CCB treatments similarly and significantly reduced the mean blood pressure (107+/-7 mmHg to 95+/-7 mmHg, p<0.0001, and 104+/-6 mmHg to 93+/-9 mmHg, p<0.0001, respectively). Losartan treatment resulted in a significant increase in HMW-adiponectin concentrations (45.9%) and a significant decrease in HOMA-R (23.9%) and FFA concentrations (26.5%); the percent changes were greater than those induced by CCB treatment (p<0.001, p<0.05 and p<0.01, respectively). We conclude that losartan increases the serum HMW-adiponectin concentration and concurrently improves insulin sensitivity in subjects with IFG/IGT. These results suggest that losartan may prevent diabetes by increasing serum adiponectin levels.

[Clinicopathological analysis of malignant nephrosclerosis].

BACKGROUND: Although pathological changes in the vascular lesions of malignant nephrosclerosis have been quantified, little is understood about interstitial changes. We quantified pathological changes such as glomerular damage (glomerular sclerosis and collapse), vascular patency and interstitial fibrosis to determine statistical correlations with clinical data. METHODS: We examined 25 patients who were diagnosed with malignant hypertension and investigated correlations among age, urinary protein, SUN, 1/Cre, systolic BP and diastolic BP (from medical charts), interstitial fibrosis, glomerular damage, acute tubular damage (semiquantified by scoring) and arterial and arteriolar patency (from renal biopsies). RESULTS: Interstitial fibrosis inversely correlated with 1/Cre (p=0.0114), interlobular arterial patency (p= 0.0139) and total vascular patency (p = 0.0499). Glomerular damage tended to correlate with urinary protein, but the values did not reach the level of statistical significance (p=0.0666). On the other hand, glomerular damage correlated with neither interstitial fibrosis nor vascular patency. Acute tubular damage closely correlated with both diastolic (p= 0.0086) and systolic (p = 0.0075) BP. CONCLUSIONS: Interstitial damage increases with decreasing interlobular arterial patency and renal function decreases with increasing interstitial damage. Since acute tubular damage that can progress to chronic interstitial damage closely correlates with BP, the control of BP might indirectly influence the prognosis of renal function.

Blood flow analysis of the head and lower limbs by the laser Doppler blood flowmeter during LDL apheresis.

The presence of peripheral arterial disease substantially increases the risk for both morbidity and mortality among end-stage renal disease patients. Low-density lipoprotein (LDL) apheresis has been also applied for the treatment of peripheral arterial disease to reduce LDL levels, resulting in the improvement of the blood flow to the ischemic limbs. In this study, we investigated the continuous changes of the tissue blood flows in the lower limbs and head during LDL-apheresis treatment by a non-invasive method (the non-invasive continuous monitoring method (NICOMM) system). In this study, the tissue blood flow in both the head and lower limbs showed a significantly enhancement from before to after treatment. The tissue blood flow in the lower limbs showed a significantly larger improvement than that in the head. The short-term effects of LDL apheresis were confirmed by using the NICOMM system; thus, this system will be useful for the determination of the appropriate schedule of LDL apheresis for long-term effectiveness.

[Histological investigation of renal pathological changes in MPO-ANCA-related nephritis using repeat renal biopsies].

We compared the histological changes before and after treatment in 14 cases of myeloperoxidase antineutrophil cytoplasmic autoantibodies (MPO-ANCA) related nephritis in whom we were able to perform two renal biopsies. The results show that the clinical findings and acute glomerular and tubulointerstitial injuries decreased, while chronic glomerular injuries increased. No changes were seen in minor glomerular abnormalities(MGAs) or chronic tubulointerstitial injuries between the first and second biopsies. In the vascular system, no treatment related aggravation of arteriosclerosis occurred and it was found that fibrinoid necrosis disappeared with treatment. Finally, in MPO-ANCA related nephritis, the care given between the first and second biopsies caused acute glomerular injuries to become chronic glomerular injuries, but no changes were detected in the MGA. We believe that the changes in acute tubulointerstitial injuries reflected an improvement in renal function, since the acute tubulointerstitial injuries obviously improved in response to PSL, contributing to the improved renal function. In other words, MPO ANCA-related nephritis is a condition that involves "acute glomerulonephritis+ acute tubulointerstitial nephritis + angiitis," and it is thought that the characteristics of each are independent. We believe that the renal function improved as the acute tubulointerstitial nephritis improved, while the acute glomerular injuries developed into chronic glomerular injuries.

Urinary excretion of creatol, an in vivo biomarker of hydroxyl radical, in patients with chronic renal failure.

Creatol (CTL) is a hydroxyl radical adduct of creatinine (Cr). The serum methylguanidine (MG) level and the MG/Cr molar ratio are reported to be biomarkers for oxidative stress. The aim of this study was to examine whether urinary excretion of CTL, another oxidative stress-related marker, is increased in patients with chronic renal failure (CRF). One hundred twenty-four non-dialyzed patients with chronic renal failure (serum Cr level, 1.3-10.0 mg/dL) were recruited from our hospitals. Urine and serum levels of CTL and MG were determined by high-performance liquid chromatography with the use of 9, 10- phenanthrenequinone as a fluorogenic reagent. The CTL/Cr and (CTL+MG)/Cr molar ratios in spot urine samples were also compared with those in 24-h urine samples. The urinary CTL/Cr and (CTL+MG)/Cr molar ratios increased with decreases in Cr clearance in patients with CRF. Correlations between serum and spot urine (CTL+MG)/Cr and between serum and spot urine CTL/Cr were quite similar to those in 24-h urine samples. CTL/Cr and (CTL+MG)/Cr molar ratios in both 24-h urine and spot urine samples appear to be useful indices of the severity of CRF.