Favorable therapeutic efficacy of low-density lipoprotein apheresis for nephrotic syndrome with impaired renal function

Many reports have shown the therapeutic efficacy of LDL apheresis (LDL-A) in drug-resistant nephrotic syndrome (NS) for improvement of heavy proteinuria and severely impaired renal function. To obtain comprehensive results in a large number of cases, a post hoc analysis of the Prospective Observational survey on the Long-Term Effects of the LDL-Apheresis on the Drug Resistant Nephrotic Syndrome (POLARIS) study was performed by stratifying enrolled cases according to the pretreatment estimated glomerular filtration rate (eGFR) levels indicating normal (N) (≥60 ml/min/1.73 m² ), moderately impaired (M) (≥30 to <60 ml/min/1.73 m² ), and severely impaired (S) (<30 ml/min/1.73 m² ) renal function. Significant improvements of proteinuria and renal function were found in Group N and, most interestingly, in Group M. A tendency for improvement in proteinuria was found in Group S. Most cases in all groups had not entered end-stage renal disease at 2 years after LDL-A treatment. These results suggest that LDL-A has therapeutic efficacy even in cases in which renal function has declined to 30 ml/min/1.73 m² .

TGF-β1 Induced by High Glucose is Controlled by Angiotensin-Converting Enzyme Inhibitor and Angiotensin II Receptor Blocker on Cultured Human Peritoneal Mesothelial Cells

Background

Loss of peritoneal function is a major complication associated with long-term peritoneal dialysis. Observed changes include loss and degeneration of the mesothelium, submesothelial thickening, alterations in the structure and number of blood vessels, and reduplication of the vascular basement membrane. Exposure to high glucose concentrations in peritoneal dialysis solutions is known to cause injury to cultured human peritoneal mesothelial cells (HPMC) as a result of overexpression of transforming growth factor beta 1 (TGF-β1). Previous studies have demonstrated that angiotensin II (AII) increases expression of TGF-β1 in a number of different cell types; although this has not been demonstrated in HPMC.

Objective

To clarify possible mechanisms involved in peritoneal fibrosis, we investigated whether HPMC expressed AII-forming pathway mRNA and whether increases in AII induced by high glucose contribute to the production of TGF-β1. We also examined the effects of the angiotensin-converting enzyme inhibitor (ACEI) perindoprilat and the AII receptor blocker (ARB) candesartan on expression of TGF-β1 and proliferation of HPMC.

Methods

Expression of mRNA for the AII-forming pathway and TGF-β1 in HPMC was examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and quantitative RT-PCR. Levels of AII and TGF-β1 following 48 hours of incubation of the cells in a range of glucose concentrations were measured by enzyme immunoassay and enzyme linked immunosorbent assay respectively. The effect of glucose on cell proliferation was examined using the water-soluble tetrazolium salt WST-1 and [3H]-thymidine uptake. We also investigated the effect of ACEI and ARB on the expression of TGF-β1 and the proliferation of HPMC incubated at high glucose for 48 hours.

Results

AII-forming pathway mRNA was detected in HPMC, with expression of angiotensinogen, angiotensin-converting enzyme (ACE), AII type 1 receptor, and TGF-β1 mRNA increasing following exposure to glucose according to glucose concentration. High glucose was also shown to increase the production of AII and TGF-β1 and decrease the proliferation of HPMC. In contrast, we found that both the ACEI and the ARB attenuated the increase in TGF-β1 production and reduced cell proliferation caused by exposure to high glucose. These effects were greater with a combination of the two drugs.

Conclusion

The present study provides evidence that ( 1 ) HPMC express mRNA for the AII-forming pathway; ( 2 ) ACEI and ARB inhibit the TGF-β1 production induced by high glucose; ( 3 ) the AII-forming pathway is one mechanism by which high glucose causes production of TGF-β1. In addition to having antihypertensive and renal-protective effects, combination therapy with an ACEI and an ARB may also be effective in preventing loss of peritoneal function and decreasing peritoneal fibrosis.

Effect of Oral Alfacalcidol on Clinical Outcomes in Patients Without Secondary Hyperparathyroidism Receiving Maintenance Hemodialysis: The J-DAVID Randomized Clinical Trial

IMPORTANCE

Patients with chronic kidney disease have impaired vitamin D activation and elevated cardiovascular risk. Observational studies in patients treated with hemodialysis showed that the use of active vitamin D sterols was associated with lower risk of all-cause mortality, regardless of parathyroid hormone levels.

OBJECTIVE

To determine whether vitamin D receptor activators reduce cardiovascular events and mortality in patients without secondary hyperparathyroidism undergoing hemodialysis.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, open-label, blinded end point multicenter study of 1289 patients in 207 dialysis centers in Japan. The study included 976 patients receiving maintenance hemodialysis with serum intact parathyroid hormone levels less than or equal to 180 pg/mL. The first and last participants were enrolled on August 18, 2008, and January 26, 2011, respectively. The final date of follow-up was April 4, 2015.

INTERVENTIONS

Treatment with 0.5 μg of oral alfacalcidol per day (intervention group; n = 495) vs treatment without vitamin D receptor activators (control group; n = 481).

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite measure of fatal and nonfatal cardiovascular events, including myocardial infarctions, hospitalizations for congestive heart failure, stroke, aortic dissection/rupture, amputation of lower limb due to ischemia, and cardiac sudden death; coronary revascularization; and leg artery revascularization during 48 months of follow-up. The secondary outcome was all-cause death.

RESULTS

Among 976 patients who were randomized from 108 dialysis centers, 964 patients were included in the intention-to-treat analysis (median age, 65 years; 386 women [40.0%]), and 944 (97.9%) completed the trial. During follow-up (median, 4.0 years), the primary composite outcome of cardiovascular events occurred in 103 of 488 patients (21.1%) in the intervention group and 85 of 476 patients (17.9%) in the control group (absolute difference, 3.25% [95% CI, -1.75% to 8.24%]; hazard ratio, 1.25 [95% CI, 0.94-1.67]; P = .13). There was no significant difference in the secondary outcome of all-cause mortality between the groups (18.2% vs 16.8%, respectively; hazard ratio, 1.12 [95% CI, 0.83-1.52]; P = .46). Of the 488 participants in the intervention group, 199 (40.8%) experienced serious adverse events that were classified as cardiovascular, 64 (13.1%) experienced adverse events classified as infection, and 22 (4.5%) experienced malignancy-related serious adverse events. Of 476 participants in the control group, 191 (40.1%) experienced cardiovascular-related serious adverse events, 63 (13.2%) experienced infection-related serious adverse events, and 21 (4.4%) experienced malignancy-related adverse events.

CONCLUSIONS AND RELEVANCE

Among patients without secondary hyperparathyroidism undergoing maintenance hemodialysis, oral alfacalcidol compared with usual care did not reduce the risk of a composite measure of select cardiovascular events. These findings do not support the use of vitamin D receptor activators for patients such as these.

TRIAL REGISTRATION

UMIN-CTR Identifier: UMIN000001194.

Factors Influencing Arteriovenous Fistula Dysfunction in Japanese Patients on Chronic Hemodialysis

Arteriovenous fistula dysfunction is a constant problem in chronic hemodialysis patients. We investigated the factors influencing fistula dysfunction in 184 patients on chronic hemodialysis. Stepwise regression analysis and Cox proportional hazards model were used to assess the relationship between fistula dysfunction and age, sex, duration of hemodialysis, diabetes mellitus, hematocrit, serum creatinine, blood urea nitrogen, KW, prothrombin time, blood pressure, anticoagulant therapy, dose of erythropoietin, calcium channel blocker therapy, and angiotensin-converting enzyme inhibitor therapy. Fistula dysfunction showed a significant relationship with a low systolic blood pressure, a low hematocrit, the presence of diabetes mellitus, and angiotensin-converting enzyme inhibitor therapy. These results suggested that treatment with angiotensin-converting enzyme inhibitors may help to prevent fistula dysfunction.

Effects of Dialysis Membranes on the Kinetics of Tumor Necrosis Factor-α Production by Peripheral Mononuclear Cells in Chronic Hemodialysis Patients

To evaluate the biocompatibility of dialysis membranes, blood samples were collected from 10 hemodialysis patients immediately before dialysis and peripheral blood mononuclear cells were isolated. The 3.0 x 105 cells/ml were then passed 30 times through modules made of a polyethylene glycolgrafted cellulose membrane, a polyacrylonitrile membrane, and a polysulfone membrane. Expression of messenger RNA for tumor necrosi factor-α (TNF-α) was determined. Cells were also cultured for 2 h with and without lipopolysaccharide and TNF-α levels in the supernatant were measured.

TNF-α messenger RNA expression was significantly higher immediately after passage through the polyacrylonitrile membrane compared with the other membranes. Cells cultured without lipopolysaccharide, produced significantly less TNF-α after passage through the polysulfone membrane, while lipopolysaccharide significantly increased TNF-α production by cells passed through the polyacrylonitrile membrane. These results suggest that biocompatibility differs even among dialysis membranes believed to cause no complement activation.

Correction of CAPD Catheter Displacement Using Gastric Biopsy Forceps: The Push-Pull Method

We corrected malpositioned continuous ambulatory peritoneal dialysis catheters in six patients using a new technique named the “push-pull method”. A gastric biopsy forceps was advanced through the catheter to near its tip. After manipulating the tip of the forceps through the abdominal wall, the forceps was opened and pulled out slowly. Repeated insertion and removal of the forceps induced the catheter to return to the pelvic cavity. This push-pull method was successful for Swan neck straight (n=2) and coiled (n=4) catheters in all patients. The time required for the procedure was only 5–10 minutes and there were no complications.

A Case of Antiphospholipid Antibody Syndrome Diagnosed after Thrombosis of an Arteriovenous Shunt

A 32-year-old male dialysis patient with lupus nephritis was admitted because of shunt obstruction. The arteriovenous fistula was reconstructed, but obstruction recurred twice within several hours after surgery. A high blood level of anticardiolipin β2-glycoprotein I antibody suggested that shunt obstruction was caused by a thrombotic tendency related to the antiphospholipid antibody syndrome. Accordingly, for the third shunt procedure, antiplatelet therapy (which had been commenced for systemic lupus erythematosus) was combined with dalteparin sodium from before surgery and warfarin was added postoperatively. This regimen prevented shunt obstruction. In conclusion, hemodialysis patients who suffer repeated shunt obstruction should be examined for antiphospholipid antibody syndrome.

Dose Conversion Ratio one year after Switching from Epoetin Alpha to Darbepoetin Alpha in Japanese Hemodialysis Patients

Background/Aims

Darbepoetin alpha is effective for renal anemia when epoetin is insufficient. We previously reported that the dose conversion ratio from epoetin alpha to darbepoetin alpha was 1:350.5 after 24 weeks of follow-up. This study assessed the conversion ratio in stable Japanese hemodialysis patients after 52 weeks.

Methods

A total of 104 hemodialysis patients who were stable on intravenous epoetin alpha were switched to intravenous darbepoetin alpha according to the 1:200 rule. Then they were followed for 52 weeks to assess changes of hemoglobin and the darbepoetin alpha dose.

Results

Eighty-five patients completed the study. Their hemoglobin increased very rapidly during the first 8 weeks. The final conversion ratio was 1:286.6 at 52 weeks. Darbepoetin alpha showed similar efficacy in diabetics and non-diabetics. Patients switching from a high epoetin alpha dose (≥4500 IU/week) had a higher conversion ratio compared with those switching from a low dose (<4500 IU/week).

Conclusions

The dose conversion ratio of 1:200 was unsuitable and led to a rapid increase of hemoglobin. A conversion ratio of 1:250 to 1:300 should be employed when switching from epoetin alpha to darbepoetin alpha in Japanese patients.

Usefulness of Immunoadsorption Therapy for Systemic Lupus Erythematosus Associated with Transverse Myelitis. A Case Report

Transverse myelitis (TM) is a very rare complication of systemic lupus erythematosus (SLE) and its prognosis is poor. It therefore needs to be treated aggressively. We describe a patient suffering from SLE associated with TM, who responded well to a combination of immunoadsorption therapy and steroid mini-pulse therapy. His serum interleukin 6 levels as well as clinical indicators fell to normal after this treatment.

Stimulation of Interleukin-1 ß Production may be Involved in Unresponsiveness to Erythropoietin Therapy

Recombinant human erythropoietin (rHuEPO) can dramatically improve anemia in dialysis patients, but about 20% of patients show a poor response to this agent. It has been reported that cytokines, including interleukin (IL)-1ß, may inhibit the maturation of erythrocytes. To investigate the mechanisms of unresponsiveness to rHuEPO, we isolated peripheral blood mononuclear cells from 12 patients on continuous ambulatory peritoneal dialysis who were receiving maintenance rHuEPO therapy for renal anemia. Cells were cultured with rHuEPO and IL-1 ß production was assessed. In the six patients who did not respond to rHuEPO therapy, there was a marked increase in IL-1 ß during culture with rHuEPO. In contrast, the addition of rHuEPO to cultures of cells from the six responding patients caused little increase in IL-1 ß, and there was a significant difference between the two groups. Induction of IL-1 ß by rHuEPO may be one cause of persistent anemia in dialysis patients.

A new peritoneal dialysis fluid for Japanese patients: a randomized non-inferiority clinical trial of safety and efficacy

BACKGROUND

We report here two new peritoneal dialysis fluids (PDFs) for Japan [BLR 250, BLR 350 (Baxter Limited, Japan)]. The PDFs use two-chamber systems, and have bicarbonate and lactate buffer to a total of 35 mmol/L. In separate trials, the new PDFs were compared to two "standard" systems [PD-4, PD-2 (Baxter Limited, Japan)]. The trials aimed to demonstrate non-inferiority of peritoneal creatinine clearance (pCcr), peritoneal urea clearance (pCurea) and ultrafiltration volume (UF), and compare acid-base and electrolyte balance.

METHODS

We performed randomized, multicenter, parallel group, controlled, open-label clinical trials in stable continuous ambulatory peritoneal dialysis (CAPD) patients. The primary endpoints were pCcr and UF. The secondary endpoints were serum bicarbonate and peritoneal urea clearance. The active phase was 8 weeks. These trials were performed as non-inferiority studies, with the lower limit of non-inferiority for pCcr and UF set at 3.2 L/week/1.73 m² and 0.12 L/day, respectively.

RESULTS

108 patients (28 centers) and 103 patients (29 centers) took part in the two trials. Groups were well balanced at baseline. The investigative PDFs were non-inferior to the "standard" ones in terms of primary endpoints, comparable in terms of pCurea, and superior in terms acid-base balance, especially correcting those with over-alkalinization at baseline.

CONCLUSIONS

We demonstrated fundamental functionality of two new PDFs and showed superior acid-base balance. Given the propensity of Japanese CAPD patients for alkalosis, it is important to avoid metabolic alkalosis which is associated with increased cardiovascular mortality risk and accelerated vascular calcification. The new PDFs are important progress of CAPD treatment for Japanese patients.

Mizoribine therapy combined with steroids and mizoribine blood concentration monitoring for idiopathic membranous nephropathy with steroid-resistant nephrotic syndrome

Background

We designed a prospective and randomized trial of mizoribine (MZR) therapy combined with prednisolone (PSL) for idiopathic membranous nephropathy (IMN) with steroid-resistant nephrotic syndrome (SRNS).

Methods

Patients with IMN were divided into 2 groups, and MZR combined with PSL was administered for 2 years. PSL was initially prescribed at 40 mg/day and tapered. MZR was given once-a-day at 150 mg and 3-times-a-day at 50 mg each to groups 1 and 2. Serum MZR concentrations from 0 to 4 h after administration were examined within one month of treatment. The concentration curve and peak serum level (C_max) of MZR were estimated by the population pharmacokinetic (PPK) parameters of MZR.

Results

At 2 years, 10 of 19 patients (52.6 %) in group 1 and 7 of 18 patients (38.9 %) in group 2 achieved complete remission (CR). The time-to-remission curve using the Kaplan–Meier technique revealed an increase in the cumulative CR rate in group 1, but no significant difference between the groups. Meanwhile, there was a significant difference in C_max between groups 1 and 2 (mean ± SD: 1.20 ± 0.52 vs. 0.76 ± 0.39 μg/mL, p = 0.04), and C_max levels in CR cases were significantly higher than those in non-CR cases. Receiver operating characteristic analysis showed that C_max more than 1.1 µg/mL was necessary for CR in once-a-day administration.

Conclusion

Administration of MZR once a day is useful when combined with PSL for treatment of IMN with SRNS. In addition, it is important to assay the serum concentration of MZR and to determine C_max, and more than 1.1 µg/mL of C_max is necessary for CR.

Hepatitis B virus infection in hemodialysis patients in Japan: Prevalence, incidence and occult hepatitis B virus infection

AIM

A survey of hepatitis B virus (HBV) infection in hemodialysis (HD) patients was conducted to determine the burden and risk of infection and to suggest preventive measures against HBV infection among HD patients at nine hospitals in Hiroshima, Japan, from 1999 to 2003.

METHODS

HBV markers were investigated for 1860 HD patients. The prevalence, incidence of HBV and prevalence of occult HBV were calculated.

RESULTS

The prevalence of hepatitis B surface antigen (HBsAg) was 2.6%, the positive rate of anti-hepatitis B core (HBc) was 20.6% and that of anti-hepatitis B surface (HBs) was 11.7%. Among 1372 patients who started HD after the approval of erythropoietin in Japan in 1991, the prevalence of HBsAg was 2.1%. The incidence rate of HBsAg positivity was 0/1000 person-years and the incidence of anti-HBc was 0.3/1000 person-years. Among 1812 HBsAg negative patients HBV DNA was detected in two: one case was negative for anti-HBc and anti-HBs, and the other was only positive for anti-HBc. Prevalence of occult HBV was 0.11%.

CONCLUSION

The incidence rate of HBV was much lower than that of hepatitis C virus (HCV) in the same cohort. We supposed that the discrepancy between incidence rate of HBV and that of HCV was caused by the difference of their carrier rates and of their characteristics for persistent infection. So, we concluded that it is prerequisite to grasp the burden of HBV carriers in the group to prevent new HBV infections in HD patients.

A Prospective Observational Survey on the Long-Term Effect of LDL Apheresis on Drug-Resistant Nephrotic Syndrome

BACKGROUND/AIMS

LDL apheresis (LDL-A) is used for drug-resistant nephrotic syndrome (NS) as an alternative therapy to induce remission by improvement of hyperlipidemia. Several clinical studies have suggested the efficacy of LDL-A for refractory NS, but the level of evidence remains insufficient. A multicenter prospective study, POLARIS (Prospective Observational Survey on the Long-Term Effects of LDL Apheresis on Drug-Resistant Nephrotic Syndrome), was conducted to evaluate its clinical efficacy with high-level evidence.

METHODS

Patients with NS who showed resistance to primary medication for at least 4 weeks were prospectively recruited to the study and treated with LDL-A. The long-term outcome was evaluated based on the rate of remission of NS 2 years after treatment. Factors affecting the outcome were also examined.

RESULTS

A total of 58 refractory NS patients from 40 facilities were recruited and enrolled as subjects of the POLARIS study. Of the 44 subjects followed for 2 years, 21 (47.7%) showed remission of NS based on a urinary protein (UP) level <1.0 g/day. The UP level immediately after LDL-A and the rates of improvement of UP, serum albumin, serum creatinine, eGFR, and total and LDL cholesterol after the treatment session significantly affected the outcome.

CONCLUSIONS

Almost half of the cases of drug-resistant NS showed remission 2 years after LDL-A. Improvement of nephrotic parameters at termination of the LDL-A treatment was a predictor of a favorable outcome.

The association of hepatitis C virus infection with the prognosis of chronic hemodialysis patients: A retrospective study of 3,064 patients between 1999 and 2010

The prevalence of hepatitis C virus (HCV) infection is high among patients receiving chronic hemodialysis. To clarify the risk ratio of HCV infection with respect to mortality and prognosis in chronic hemodialysis patients, a retrospective longitudinal cohort study was conducted in 2010 and involved 3,064 patients receiving chronic hemodialysis at nine dialysis facilities in Hiroshima, Japan, who were recruited from 1999 to 2003. Logistic regression and Cox hazards models were used to estimate the mortality risk among hemodialysis patients. Among the patients, 422 (14.0%) were positive for HCV RNA. HCV RNA positivity was associated with death in the logistic model (adjusted odds ratio = 1.79; P < 0.001). However, it was not a risk factor for the reduced of survival rate in the Cox proportional hazard model (adjusted risk ratio = 1.07; P = 0.4138). In summary, among hemodialysis patients, HCV RNA is correlated with the mortality rate; however, it is not significantly correlated with prognosis in terms of survival time. On the other hand, diabetes and age at dialysis onset are significantly correlated with survival. Diabetes control treatment should be preferentially selected for hemodialysis patients, and antiviral therapy for HCV should be introduced based on the clinical state of the patient. J. Med. Virol. 87:1558–1564, 2015. © 2015 The Authors. Journal of Medical Virology published by Wiley Periodicals, Inc.

Telomeric g-tail length and hospitalization for cardiovascular events in hemodialysis patients

BACKGROUND AND OBJECTIVES

Telomeric G-tails play a pivotal role in maintaining the intramolecular loop structure of telomeres. Previous in vitro studies have suggested that the erosion of telomeric G-tails triggers cellular senescence, leading to organ dysfunction and atherosclerosis. The authors recently established a method to measure telomeric G-tail length using a hybridization protection assay. Using this method, this study investigated whether telomeric G-tail length could be used as a novel predictor for future cardiovascular events in hemodialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A prospective observational study was performed involving a cohort of 203 Japanese hemodialysis patients to examine the lengths of telomeric G-tails and total telomeres and subsequent cardiovascular events during a median follow-up period of 48 months. The lengths of telomeric G-tails and total telomeres were also measured in 203 participants who did not have CKD and who were age- and sex-matched to hemodialysis patients.

RESULTS

The lengths of telomeric G-tails and total telomeres were significantly shorter in hemodialysis patients than in control subjects. Telomeric G-tails, but not total telomeres, were independently and negatively associated with clinical history of cardiovascular disease. During follow-up, 80 cardiovascular events occurred. Total telomere length did not predict cardiovascular events. However, the length of telomeric G-tails was associated with new-onset cardiovascular events (hazard ratio per log luminescence signals, 0.12; 95% confidence interval, 0.12 to 0.50) that persisted after adjustment for age, sex, diabetes mellitus, clinical history of cardiovascular disease, inflammation, use of vitamin D, and serum levels of phosphate and intact parathyroid hormone.

CONCLUSIONS

Longer telomeric G-tail length is associated with a lower risk of future cardiovascular events in hemodialysis patients.

Significance of combined cyclosporine-prednisolone therapy and cyclosporine blood concentration monitoring for idiopathic membranous nephropathy with steroid-resistant nephrotic syndrome: a randomized controlled multicenter trial

Background

Combined treatment with cyclosporine microemulsion preconcentrate (CyA MEPC) and steroids has been widely used for idiopathic membranous nephropathy (IMN) associated with steroid-resistant nephrotic syndrome (SRNS). Recent studies have shown that once-a-day and preprandial administration of CyA MEPC is more advantageous than the conventional twice-a-day administration in achieving the target blood CyA concentration at 2 h post dose (C2). We designed a randomized trial to compare these administrations.

Methods

IMN patients with SRNS (age 16–75 years) were divided prospectively and randomly into 2 groups. In group 1 (n = 23), 2–3 mg/kg body weight (BW) CyA MEPC was given orally once a day before breakfast. In group 2 (n = 25), 1.5 mg/kg BW CyA MEPC was given twice a day before meals. CyA + prednisolone was continued for 48 weeks.

Results

Group 1 showed a significantly higher cumulative complete remission (CR) rate (p = 0.0282), but not when incomplete remission 1 (ICR1; urine protein 0.3–1.0 g/day) was added (p = 0.314). Because a C2 of 600 ng/mL was determined as the best cut-off point, groups 1 and 2 were further divided into subgroups A (C2 ≥600 ng/mL) and B (C2 <600 ng/mL). Groups 1A and 2A revealed significantly higher cumulative remission (CR + ICR1) (p = 0.0069) and CR-alone (p = 0.0028) rates. On the other hand, 3 patients with high CyA levels (C2 >900 ng/mL) in Group 1A were withdrawn from the study because of complications.

Conclusion

CyA + prednisolone treatment is effective for IMN with associated SRNS at a C2 of ≥600 ng/mL. To achieve remission, preprandial once-a-day administration of CyA at 2–3 mg/kg BW may be the most appropriate option. However, we should adjust the dosage of CyA by therapeutic drug monitoring to avoid complications.

Plasma osteoprotegerin, arterial stiffness, and mortality in normoalbuminemic Japanese hemodialysis patients

A high circulating osteoprotegerin (OPG) level may be a risk factor for vascular calcification and mortality in hemodialysis patients. OPG and pulse wave velocity (PWV) were measured at baseline in 151 normoalbuminemic, long-term (>3 years) Japanese hemodialysis patients who were prospectively followed for 6 years. In long-term normoalbuminemic Japanese hemodialysis patients, OPG levels were strongly linked with both arterial stiffness and worse outcome.

INTRODUCTION

A high circulating OPG level is reported to be a risk factor for vascular calcification and mortality in Western chronic kidney disease (CKD) patients but it is not known if this is true for Japanese CKD patients, where a different risk profile may operate.

METHODS

OPG and PWV were measured at baseline in 151 normoalbuminemic, long-term (>3 years) Japanese hemodialysis patients (median age 62 years) who were prospectively followed for 6 years.

RESULTS

OPG levels were associated in multivariate analysis with age, dialysis vintage, history of cardiovascular disease (CVD) and parathyroid hormone levels. C-reactive protein levels did not correlate with OPG. Patients with clinical history of CVD had significantly higher OPG levels and OPG levels were positively correlated to PWV, an index of arterial stiffness. These associations were independent of age, sex, dialysis vintage, and diabetes. During the follow-up period, 40 deaths, including 25 cardiovascular deaths, were recorded. In crude analysis, each unit of increase in OPG was associated with increased all-cause (hazard ratios 1.14, 95% confidence interval 1.08-1.20) and CVD mortality (1.14 [1.07-1.21]), which persisted after adjustment for age, sex, dialysis vintage, diabetes, and baseline CVD (1.12 [1.05-1.19] and 1.11 [1.02-1.19], all-cause and CVD mortality, respectively).

CONCLUSIONS

In long-term normoalbuminemic Japanese hemodialysis patients, with low prevalence of inflammation, OPG levels were strongly linked with both arterial stiffness and worse outcome.

Endogenous estrogen may prevent bone loss in postmenopausal hemodialysis patients throughout life

SUMMARY

Postmenopausal hemodialysis patients are at risk of complications related to renal mineral and bone disorder, and postmenopausal osteoporosis. In 112 postmenopausal hemodialysis patients, free estrogen index was positively correlated with bone mineral density (BMD) Z-score and the annual percent change of BMD in multiple regression analysis. Endogenous estrogen may prevent bone loss in postmenopausal hemodialysis patients throughout life.

INTRODUCTION

Women on dialysis are not only at risk of developing mineral and bone disorder, but also suffer from postmenopausal osteoporosis. We assessed the effect of sex hormones on bone metabolism in postmenopausal hemodialysis patients.

METHODS

We enrolled 112 postmenopausal hemodialysis patients with a mean age of 68.4 ± 10.4 years. We measured the serum levels of estradiol, testosterone, sex hormone-binding globulin (SHBG), and intact parathyroid hormone (intact-PTH), as well as bone metabolism parameters and radial bone mineral density (BMD). The free estrogen index (FEI) was calculated from the estradiol and SHBG values. After conventional dialysis was performed for 12 months, BMD was measured again and the annual percent change was calculated. Estradiol and SHBG were also measured in 25 postmenopausal women without chronic kidney disease.

RESULTS

Estradiol levels were higher in the hemodialysis patients than in the postmenopausal women without chronic kidney disease. In patients with relatively normal bone turnover (intact-PTH: from 150 to 300 pg/ml), the FEI showed a positive correlation with the BMD Z-score. The annual percent change of BMD showed a positive correlation with the FEI according to multiple regression analysis.

CONCLUSIONS

Endogenous estrogen may prevent bone loss in postmenopausal hemodialysis patients throughout life.

Klotho inhibits transforming growth factor-beta1 (TGF-beta1) signaling and suppresses renal fibrosis and cancer metastasis in mice

Fibrosis is a pathological process characterized by infiltration and proliferation of mesenchymal cells in interstitial space. A substantial portion of these cells is derived from residing non-epithelial and/or epithelial cells that have acquired the ability to migrate and proliferate. The mesenchymal transition is also observed in cancer cells to confer the ability to metastasize. Here, we show that renal fibrosis induced by unilateral ureteral obstruction and metastasis of human cancer xenografts are suppressed by administration of secreted Klotho protein to mice. Klotho is a single-pass transmembrane protein expressed in renal tubular epithelial cells. The extracellular domain of Klotho is secreted by ectodomain shedding. Secreted Klotho protein directly binds to the type-II TGF-β receptor and inhibits TGF-β1 binding to cell surface receptors, thereby inhibiting TGF-β1 signaling. Klotho suppresses TGF-β1-induced epithelial-to-mesenchymal transition (EMT) responses in cultured cells, including decreased epithelial marker expression, increased mesenchymal marker expression, and/or increased cell migration. In addition to TGF-β1 signaling, secreted Klotho has been shown to inhibit Wnt and IGF-1 signaling that can promote EMT. These results have raised the possibility that secreted Klotho may function as an endogenous anti-EMT factor by inhibiting multiple growth factor signaling pathways simultaneously.

[N-terminal pro brain natriuretic peptide predicts hospitalization of hemodialysis patients for cardiovascular disease]

We investigated whether or not N-terminal pro brain natriuretic peptide (NT-proBNP) could predict hospitalization for cardiovascular disease (CVD) among Japanese hemodialysis patients. A total of 104 patients on maintenance dialysis 3 times per week were enrolled. We followed the patients for 23.9 +/- 4.2 months and 19 hospitalizations for CVD occurring during this period. The area under the curve (AUC) for the risk of CVD hospitalization was calculated after drawing a receiver operating characteristic curve. Predialysis NT-proBNP showed a larger AUC value than both postdialysis NT-proBNP and brain natriuretic peptide. The optimal cut-off value of predialysis NT-proBNP for predicting CVD hospitalization was 5,894 pg/mL, (sensitivity of 60 % and specificity of 76 %). Diabetes mellitus, a history of CVD, and the predialysis NT-proBNP level were significant determinants of CVD hospitalization according to Cox proportional hazards analysis. In conclusion, predialysis NT-proBNP is useful for predicting CVD hospitalization in hemodialysis patients.

Point mutation (C to T) of the LCAT gene resulting in A140C substitution

Familial lecithin: cholesterol acyltransferase (LCAT) deficiency is an autosomal recessive disorder characterized by corneal opacity, hemolytic anemia, proteinuria, and a low serum level of high-density lipoprotein cholesterol (HDL-C). Also, LCAT activity is remarkably decreased or absent. A 57-year-old Japanese man presented with corneal opacity, proteinuria, and a very low serum level of HDL-C. His LCAT activity was too low to measure. From clinical observations and results of examinations, we suspected LCAT deficiency. We performed a kidney biopsy and gene analysis. Light microscopy revealed the vacuolation of glomerular capillary tufts. Electron microscopy revealed small deposits in the glomerular basement membrane (GBM), extracellular matrix, and vascular endothelial cells. We identified a homozygous C to T point mutation at nucleotide 501 (g.501 C>T) of exon 4 at codon 140, resulting in an arginine (Arg) to cysteine (Cys) amino acid substitution (A140C) in the patient. These findings were characteristic of LCAT deficiency, which was confirmed to be due to a mutation that has only been reported in Japan.

Dose conversion ratio one year after switching from epoetin alpha to darbepoetin alpha in Japanese hemodialysis patients

BACKGROUND/AIMS

Darbepoetin alpha is effective for renal anemia when epoetin is insufficient. We previously reported that the dose conversion ratio from epoetin alpha to darbepoetin alpha was 1:350.5 after 24 weeks of follow-up. This study assessed the conversion ratio in stable Japanese hemodialysis patients after 52 weeks.

METHODS

A total of 104 hemodialysis patients who were stable on intravenous epoetin alpha were switched to intravenous darbepoetin alpha according to the 1:200 rule. Then they were followed for 52 weeks to assess changes of hemoglobin and the darbepoetin alpha dose.

RESULTS

Eighty-five patients completed the study. Their hemoglobin increased very rapidly during the first 8 weeks. The final conversion ratio was 1:286.6 at 52 weeks. Darbepoetin alpha showed similar efficacy in diabetics and non-diabetics. Patients switching from a high epoetin alpha dose (> or =4500 IU/week) had a higher conversion ratio compared with those switching from a low dose (<4500 IU/week).

CONCLUSIONS

The dose conversion ratio of 1:200 was unsuitable and led to a rapid increase of hemoglobin. A conversion ratio of 1:250 to 1:300 should be employed when switching from epoetin alpha to darbepoetin alpha in Japanese patients.

Assessment of renal fibrosis with diffusion-weighted MR imaging: study with murine model of unilateral ureteral obstruction

PURPOSE

To test, in a murine model of unilateral ureteral obstruction (UUO), whether the magnetic resonance (MR) imaging-derived apparent diffusion coefficient (ADC) changes during the progression of renal fibrosis and correlates with the histopathologic changes observed in renal fibrogenesis.

MATERIALS AND METHODS

This study was approved by the institutional animal care and use committee. A UUO was created in each of 14 mice. In five mice, longitudinal diffusion-weighted (DW) imaging was performed before the UUO (day 0) and on days 3 and 7 after the UUO and was followed by histopathologic analysis. The nine remaining mice were examined with cross-sectional studies on days 0 (n = 4) and 3 (n = 5). ADCs were measured with a spin-echo echo-planar sequence at five b values ranging from 350 to 1200 sec/mm(2). Differences in ADC among the time points and between the sides were assessed by using Tukey-Kramer and Student t tests, respectively. ADC was correlated with cell density and alpha-smooth muscle actin (alpha-SMA, a marker of myofibroblasts) expression at linear regression analysis.

RESULTS

Histopathologic examination revealed typical renal fibrosis on the side with UUO. The ADC decreased over time on the UUO side, from (1.02 +/- 0.06 [standard deviation]) x 10(-3) mm(2)/sec on day 0 to (0.70 +/- 0.08) x 10(-3) mm(2)/sec on day 3 (P < .001) and (0.57 +/- 0.10) x 10(-3) mm(2)/sec on day 7 (P < .001). The percentage change in ADC was greater on the UUO side than on the contralateral side on days 3 (29% +/- 9, P = .05) and 7 (44% +/- 11, P < .01). ADC correlated with both increased cell density and increased alpha-SMA expression (P < .001 for both correlations).

CONCLUSION

An ADC decrease in renal fibrosis is associated with an increased number of cells, including fibroblasts. ADC has the potential to serve as a sensitive noninvasive biomarker of renal fibrosis.

[The role of PPARgamma agonists in kidney diseases]

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a ligand-dependent transcription factor that has a central role in the regulation of insulin sensitivity and adipocyte differentiation. Expression of PPARgamma has been reported in the kidney, including medullary collecting ducts, glomeruli and tubular cells. Thiazolidinediones (TZDs) are synthetic PPARgamma agonists and are used widely in patients with type 2 diabetes. It has been gradually discovered that TZDs have various other actions, such as vascular protective, anti-inflammatory, anti-fibrotic and anti-proliferative actions, over and above their effects on glucose and lipid metabolism. In this review, we will focus on current knowledge and insights on the role of PPARgamma agonists in kidney diseases, especially in diabetic nephropathy, non-diabetic kidney diseases and dialysis therapy.

C-C chemokine receptor 2 expression by circulating monocytes influences atherosclerosis in patients on chronic hemodialysis

Mortality from cardiovascular or cerebrovascular disease due to atherosclerosis is increased in patients on chronic hemodialysis. Monocyte chemoattractant protein-1 and its receptor, C-C chemokine receptor 2, play an important role in recruiting monocytes to atherosclerotic lesions. The relationship between atherosclerosis in hemodialysis patients and C-C chemokine receptor 2 expression is unknown. Fifty-six patients on chronic hemodialysis and 27 age- and sex-matched controls were enrolled. Serum levels of monocyte chemoattractant protein-1 and expression of C-C chemokine receptor 2 by circulating monocytes were determined. Atherosclerosis was evaluated from the carotid intima-media thickness and cardio-ankle vascular index. Serum levels of monocyte chemoattractant protein-1 and expression of C-C chemokine receptor 2 by monocytes were significantly higher in the hemodialysis patients than the controls. Multiple regression analysis showed a positive correlation between receptor expression and both indexes of atherosclerosis. C-C chemokine receptor 2 expression by circulating monocytes influences atherosclerosis in patients on chronic hemodialysis.

Effect of a carbonaceous oral adsorbent on the progression of CKD: a multicenter, randomized, controlled trial

BACKGROUND

The carbonaceous oral adsorbent AST-120 slows the deterioration of kidney function in patients with advanced chronic kidney disease (CKD). However, information about AST-120 in patients with less severe stages of CKD is lacking.

STUDY DESIGN

Randomized controlled trial.

SETTING & PARTICIPANTS

75 medical facilities, 460 patients with CKD with serum creatinine (sCr) concentrations less than 5.0 mg/dL (not undergoing dialysis).

INTERVENTION

Random assignment to either a low-protein diet and antihypertensive medication in the control group or that treatment combined with AST-120 (6 g/d).

OUTCOMES & MEASUREMENTS

Composite primary end point: doubling of sCr level, increase in sCr level to 6.0 mg/dL or more, need for dialysis or transplantation, or death.

SECONDARY OUTCOMES

adverse events and changes in estimated creatinine clearance (CCr) rate, proteinuria (protein in milligrams per day), and quality of life.

RESULTS

Mean sCr level was 2.66 mg/dL and estimated CCr was 22.4 mL/min in both groups. During 56 weeks, numbers of primary end-point events (43 for control versus 42 for AST-120) and event-free survival (P = 0.9) did not differ between groups. Gastrointestinal adverse events were less common in the control group than the AST-120 group (2 versus 32 events). Estimated CCr decreased more in the control group than in the AST-120 group (-15% per year versus -12% per year, relative to the baseline value; [corrected] P = 0.001). Median proteinuria changed from protein of 1,162 to 1,167 mg/d in the control group versus 1,102 to 906 mg/d in the AST-120 group (P = 0.2).

LIMITATION

Infrequent primary end-point events.

CONCLUSION

AST-120 did not substantially slow the progression of kidney disease in patients with moderate to severe CKD during 1 year.

Mizoribine suppresses the progression of experimental peritoneal fibrosis in a rat model

BACKGROUND/AIMS

Peritoneal fibrosis is a serious complication of peritoneal dialysis (PD). It has been reported that administration of mizoribine, an effective immunosuppressant, ameliorated renal fibrosis in a rat model of unilateral ureteral obstruction. We therefore examined the effects of mizoribine in an experimental model of peritoneal fibrosis.

METHODS

24 rats were given a daily intraperitoneal injection of chlorhexidine gluconate and ethanol dissolved in saline. The rats were divided into three groups (n = 8 per group) that received either vehicle or mizoribine at a dose of 2 or 8 mg/kg once a day. 28 days after the start of the treatments the rats were sacrificed and peritoneal tissue samples collected. Macrophage infiltration (ED1), myofibroblast accumulation (alpha-smooth muscle actin (SMA)) and expression of type III collagen, transforming growth factor (TGF)-beta and monocyte chemotactic protein-1 (MCP-1) were examined by immunohistochemistry.

RESULTS

Mizoribine significantly suppressed submesothelial zone thickening and reduced macrophage infiltration. Mizoribine also reduced collagen III(+) area and decreased the number of alpha-SMA(+), TGF-beta(+) and MCP-1(+) cells. The magnitude of the changes observed was dose-dependent.

CONCLUSION

The administration of mizoribine prevented the progression of peritoneal fibrosis in this rat model. Mizoribine may represent a novel therapy for peritoneal sclerosis in patients undergoing long-term PD.

Calcium channel antagonists reduce restenosis after percutaneous transluminal angioplasty of an arteriovenous fistula in hemodialysis patients

Percutaneous transluminal angioplasty (PTA) for stenosis of hemodialysis fistulas is associated with a high incidence of restenosis, and improvement of the patency rate after PTA is greatly needed. In addition, angiotensin II receptor blockers (ARB), calcium channel antagonists (CCA) and antiplatelet agents (APA) are commonly administered to most hemodialysis patients. This study retrospectively examined the effect of these medications on the incidence of restenosis after angioplasty for hemodialysis fistulae. The subjects were 92 patients--54 with anastomotic stenosis of an arteriovenous fistula (AVF) and 38 with stenosis of the draining veins of an arteriovenous graft (AVG)--who underwent angioplasty between January 2001 and December 2003. The patency period was defined as the interval from the first to the second angioplasty or surgical reconstruction. We excluded patients who received angioplasty two or more times. The effect of each drug on the patency of the AVF or AVG was assessed by the Kaplan-Meier method with the log-rank test and multiple logistic regression analysis. The group receiving CCA therapy showed a higher patency rate for both an AVF and an AVG. Although multiple logistic regression analysis also showed that a CCA reduces restenosis independently in an AVF, there was no significant correlation between a CCA and patency in an AVG. Treatment with an ARB and an APA was not associated with significantly higher patency rates for either an AVF or AVG. A CCA may reduce the incidence of restenosis after percutaneous intervention for stenosis of an AVF.

Activation of signal transducer and activator of transcription 3 correlates with cell proliferation and renal injury in human glomerulonephritis

BACKGROUND

Signal transducer and activator of transcription (STAT) 3 plays an important role in the regulation of cell proliferation. However, the mechanism of STAT3 activation in human glomerulonephritis is unclear.

METHODS

STAT3 activation was determined using immunohistochemistry for phosphorylated STAT3 (p-STAT3) in normal human kidney and various types of glomerulonephritis. We also identified the cell exhibiting activated p-STAT3 expression in human glomerulonephritis and correlated STAT3 activation with renal function and histologic injury.

RESULTS

p-STAT3 staining was identified in glomeruli and some tubules in normal human kidney. p-STAT3 positive glomerular cells were significantly increased in lupus nephritis, IgA nephropathy and vasculitis compared with normal kidney. p-STAT3 positive tubulointerstitial cells were significantly increased in IgA nephropathy and vasculitis compared with normal kidney. Glomerular and tubulointerstitial p-STAT3 staining was significantly decreased after steroid therapy. There was a significant correlation between the number of p-STAT3 positive cells and the number of PCNA positive glomerular and tubulointerstitial cells in all cases of glomerulonephritis. Furthermore, renal function inversely correlated with the number of p-STAT3 positive glomerular and tubulointerstitial cells in all cases of glomerulonephritis.

CONCLUSIONS

The present study has identified STAT3 activation in normal human kidney and a marked increase in STAT3 activation in many forms of glomerulonephritis. The correlation of STAT3 activation with clinical and histologic parameters suggests that this pathway plays an important role in the pathogenesis of kidney disease. Furthermore, localization of STAT3 activation to individual cell types suggests that this pathway may play a pivotal role in promoting renal inflammation and fibrosis.

DEC1 modulates the circadian phase of clock gene expression

DEC1 suppresses CLOCK/BMAL1-enhanced promoter activity, but its role in the circadian system of mammals remains unclear. Here we examined the effect of Dec1 overexpression or deficiency on circadian gene expression triggered with 50% serum. Overexpression of Dec1 delayed the phase of clock genes such as Dec1, Dec2, Per1, and Dbp that contain E boxes in their regulatory regions, whereas it had little effect on the circadian phase of Per2 and Cry1 carrying CACGTT E' boxes. In contrast, Dec1 deficiency advanced the phase of the E-box-containing clock genes but not that of the E'-box-containing clock genes. Accordingly, DEC1 showed strong binding and transrepression on the E box, but not on the E' box, in chromatin immunoprecipitation, electrophoretic mobility shift, and luciferase reporter assays. Dec1-/- mice showed behavioral rhythms with slightly but significantly longer circadian periods under conditions of constant darkness and faster reentrainment to a 6-h phase-advanced shift of a light-dark cycle. Knockdown of Dec2 with small interfering RNA advanced the phase of Dec1 and Dbp expression, and double knockdown of Dec1 and Dec2 had much stronger effects on the expression of the E-box-containing clock genes. These findings suggest that DEC1, along with DEC2, plays a role in the finer regulation and robustness of the molecular clock.

An oral adsorbent, AST-120, combined with a low-protein diet and RAS blocker, for chronic kidney disease

BACKGROUND

A low-protein diet and treatment with renin-angiotensin system (RAS) blockers can delay the progression of chronic kidney disease (CKD). The oral adsorbent AST-120 (Kremezin) has a renoprotective effect by reducing serum levels of uremic toxins. We investigated the influence of AST-120 on the preservation of renal function in patients with CKD.

METHODS

Twenty-eight patients were randomized to 2 groups: 15 patients receiving 6.0 g of AST-120 daily for 12 months plus a low-protein diet and RAS blocker therapy (group A) and 13 patients who were not given AST-120 (group B). All of them had shown progressive deterioration of renal function with basal treatment. Mean baseline serum creatinine level (+/- standard deviation) was 2.4 +/- 0.8 mg/dL in group A and 2.7 +/- 0.8 mg/dL in group B. There were no significant differences in background parameters before AST-120 therapy.

RESULTS

The change in the estimated glomerular filtration rate (eGFR) was significantly smaller in group A than in group B. The change was also significantly smaller in patients with a baseline serum creatinine <2.4 mg/dL and in patients with rapid progression. After 12 months, the slope of the eGFR curve was significantly less steep compared with baseline in group A (-1.77 vs. -0.52 ml/min per month), but there was no significant change in group B. The slope was also significantly less steep in patients with rapid progression.

CONCLUSIONS

Adding AST-120 to a low-protein diet and RAS blocker therapy may delay the deterioration of chronic renal failure, especially in patients with early or rapid progression.

Glucose-based PD solution, but not icodextrin-based PD solution, induces plasminogen activator inhibitor-1 and tissue-type plasminogen activator in human peritoneal mesothelial cells via ERK1/2

Peritoneal dialysis (PD) solutions containing glucose are considered to cause peritoneal fibrosis. Plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (t-PA) participate in fibrogenesis of various organs, and human peritoneal mesothelial cells (HPMC) can produce PAI-1 and t-PA following glucose stimulation. Icodextrin has been widely used as an alternative osmotic agent. In this study, we investigated whether icodextrin-based PD solution reduced the production of PAI-1 and t-PA by HPMC. We also examined the involvement of extracellular signal-regulated kinase 1/2 (ERK1/2). Glucose-based PD solutions increased the production of PAI-1 and t-PA by HPMC, whereas icodextrin-based PD solution exerted lesser effects. Glucose-based PD solutions activated ERK1/2, and PD98059 inhibited the production of PAI-1 and t-PA-responses not observed with icodextrin-based PD solution. In conclusion, glucose-based PD solutions, unlike icodextrin-based PD solution, induce overproduction of PAI-1 and t-PA via the ERK1/2 pathway.

Protective effects of peroxisome proliferator-activated receptor gamma ligand on apoptosis and hepatocyte growth factor induction in renal ischemia-reperfusion injury

BACKGROUND

Renal ischemia-reperfusion injury affects the long-term outcome of renal graft survival. Thiazolidinediones (TZDs), synthetic peroxisome proliferator-activated receptor (PPAR)-gamma ligands, have been shown to exert therapeutic effects upon renal ischemia-reperfusion injury far beyond their use as insulin sensitizers. It has also been reported that hepatocyte growth factor (HGF) has a beneficial effect on renal ischemia-reperfusion injury and that TZDs induce increased HGF mRNA expression and protein secretion. We investigated the effect of troglitazone, one of the TZDs, in a rat model of renal ischemia-reperfusion injury.

METHODS

A 45-minute period of warm renal ischemia was induced by bilateral clamping at 37 degrees C with rats being sacrificed before the onset of ischemia and at 2, 4, 6, and 12 hr after reperfusion. The expression of PPAR-gamma was measured by reverse-transcriptase polymerase chain reaction (RT-PCR) and western blotting while the production of HGF was investigated by RT-PCR and immunohistochemistry. The effect of troglitazone treatment on the level of apoptosis was determined by staining for cleaved caspase-3 and single-stranded DNA (ssDNA).

RESULTS

The numbers of cleaved caspase-3 and ssDNA positive cells were decreased in rats treated with troglitazone. The production of HGF mRNA and protein was most intense at 4 hr. The expression of PPAR-gamma and HGF was increased in the group treated with troglitazone compared with the control group. CONCLUSIONS.: Pretreatment of rats with the PPAR-gamma ligand troglitazone decreased apoptotic cell death in renal ischemia-reperfusion injury as a result of the induction of HGF.

Beneficial effect of low-density lipoprotein apheresis (LDL-A) on refractory nephrotic syndrome (NS) due to focal glomerulosclerosis (FGS)

AIMS

Hypercholesterolemia is one of the factors which deteriorate renal function in NS especially due to FGS. LDL-A is a potential option for treating NS due to FGS accompanied by hypercholesterolemia and resistant to conventional drug therapy with steroids and/or cyclosporine A (CsA). As reported by Muso et al. [2001], LDL-A combined with drug therapy yields more rapid relief from NS and better prognosis than drug therapy alone. However, very limited data are available on outcome at several years after treatment. The aim of this study was to clarify long-term outcome of NS patients treated with LDL-A and to evaluate the effectiveness of this treatment.

PATIENTS AND METHODS

To clarify the long-term outcome of LDL-A, we conducted a retrospective survey on outcome up to 5 years. From 36 hospitals in Japan, 41 patients with NS whose short-term outcomes with LDL-A were reported from 1999-2004 were collected and analyzed.

RESULTS

In all, 29 and 15 patients with outcomes determined at 2 and 5 years after treatment, respectively, were obtained. At 2 and 5 years after treatment, 62 and 87% of patients, respectively, were classified into complete or Type 1 incomplete remission. The strength of correlations between outcome and several factors including parameters of renal function measured before and after treatment and treatment condition revealed that early administration of LDL-A after the onset of NS provided a good long-term outcome. The data also suggest that more drastic decrease of LDL favored a better prognosis.

CONCLUSIONS

In NS due to FGS treated with LDL-A, long-term outcome was as good as short-term outcome. Early administration of LDL-A after the onset of NS provided a good long-term outcome. To obtain more precise findings regarding the effects of this treatment, a large-scale prospective study will be needed.

Effects of icodextrin on glycemic and lipid profiles in diabetic patients undergoing peritoneal dialysis

AIM

Icodextrin reduces glucose absorption from the peritoneal dialysate. We conducted this prospective, open-labeled, multicenter study to determine the effects of icodextrin on glycemic and lipid parameters in diabetic patients undergoing continuous ambulatory peritoneal dialysis (PD) or automated PD.

METHODS

Patients were recruited from 15 institutions in Japan, and a total of 51 patients (15 women and 36 men, mean age: 59 +/- 10 years, median duration of PD: 13 months) were enrolled. The patients were administered an overnight or daytime dwell of 1.5 or 2.0 l of 7.5% icodextrin-containing solution. At baseline and 3, 6, 9 and 12 months after the start of icodextrin, nonfasting blood was drawn for measurement of glycated hemoglobin (HbA1C) and serum lipids.

RESULTS

During icodextrin treatment, there was no change in overall HbA1C levels compared to baseline values; however, for those with baseline HbA1C > or =6.5% (n = 22), significant decreases in HbA1C were observed. Mean total/LDL cholesterol and triglycerides were decreased significantly during icodextrin treatment, with greater decreases for patients with baseline total cholesterol > or =220 mg/dl, LDL cholesterol > or =120 mg/dl or triglycerides > or =150 mg/dl. HDL cholesterol did not differ at any time point; however, values for patients with baseline HDL cholesterol <40 mg/dl tended to increase with marginal significance.

CONCLUSIONS

In the current study, switching from glucose-containing dialysis solution to icodextrin resulted in improved lipid profiles and possibly a favorable metabolic profile, particularly in patients with poor glycemic control. These hypotheses remain to be proven in controlled clinical trials.

Performance of polysulfone membrane dialyzers and dialysate flow pattern

BACKGROUND

It is important to observe the flow pattern of dialysate when evaluating dialyzer function and developing the most appropriate design. We investigated dialysate flow through two polysulfone membrane dialyzers (TS-UL [Toray Medical] and APS-S [Asahi Medical]) by computed tomography (CT), with barium sulfate as the contrast medium. We also performed a clinical comparison of these two dialyzers.

METHODS

For the in vitro experiment, after confirming the steady-state flow of mock blood (xanthan gum solution; 200 ml/min) and dialysate (500 ml/min), fresh dialysate, containing 5% (w/v) barium sulfate was perfused, and longitudinal CT scans of the dialyzer were obtained. Then the concentration of barium sulfate was measured (in Hounsfield units) in three fixed regions of interest. For the in vivo experiment, 12 patients on stable hemodialysis who had been using the APS-S for more than 1 month were switched to the TS-UL for 1 month and changes in various parameters were assessed.

RESULTS

The distribution of dialysate was homogeneous on CT scans of the TS-UL, but not on scans of the APS-S. The dialysate concentration curves for the three regions of interest were similar with the TS-UL, but not with the APS-S. Clearance of urea nitrogen and albumin loss were both significantly higher with the TS-UL than with the APS-S. The decrease in alpha 1-microglobulin was larger with the TS-UL than with the APS-S, but not significantly.

CONCLUSIONS

Clearance of substances over a wide range of molecular weights was higher with the TS-UL than with the APS-S, and differences in the design of the dialysate compartment may have been involved in this feature.