2009 Japanese Society for Dialysis Therapy guidelines for peritoneal dialysis. Ther Apher Dial. 2010;14:489-504. [PMID: 21118358 DOI: 10.1111/j.1744-9987.2010.00901.x]

Urgent-start peritoneal dialysis

Peritoneal dialysis is an important form of kidney replacement therapy. Most patients presenting with an unplanned, urgent need for dialysis are prescribed haemodialysis, leading to peritoneal dialysis underutilisation. Urgent-start peritoneal dialysis refers to treatment that is commenced within 2 weeks of catheter placement. Urgent-start peritoneal dialysis represents an efficacious, cost-effective alternative to the conventional approach of commencing dialysis. There is a paucity of evidence to guide management, however experience with the technique is increasing. This article overviews the rationale and practical application of urgent-start peritoneal dialysis.

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.

Literature review: Combined therapy with peritoneal dialysis and hemodialysis as renal replacement therapy

Background

Peritoneal dialysis (PD) is the recommended renal replacement therapy for patients with end-stage kidney disease. Complementary hemodialysis (HD) once per week for PD patients can aid in achieving adequate dialysis and extend the duration of PD treatment. In Japan, this therapy is termed “combined therapy with PD and hemodialysis (combPDHD).” CombPDHD represents a treatment option for PD patients for whom adequate dialysis cannot be maintained. CombPDHD has been widely applied in Japanese PD patients; however, it is much less common outside of Japan. Clinical evidence, particularly regarding long-term prognosis and appropriate duration of treatment, remains insufficient.

Summary

CombPDHD will be required as an alternative for increasing the dose of PD under various conditions, such as a loss of residual kidney function (RKF) and peritoneal functional failure. The Japanese regimen for combPDHD involves 5 or 6 days of PD, combined with one weekly session of hemodialysis. According to some reports, the potential benefits of combPDHD are peritoneal rest with improved peritoneal function and delay in membrane deterioration. CombPDHD prevents peritoneal dysfunction and reduces cardiovascular complications by adjusting the fluid volume and improving renal anemia. Increased D/PCr indicates a deterioration in peritoneal function and is an independent risk factor for encapsulating peritoneal sclerosis (EPS). It is previously reported that no significant differences in combPDHD duration were observed between EPS and non-EPS groups. Laparoscopic findings involving patients with combPDHD revealed that there was a difference in abdominal wall degeneration depending on the intra-abdominal cavity of each case. Recently, prospective studies on long-term peritoneal function, survival, and hospitalization in combPDHD have been reported. However, reviews evaluating combPDHD long-term outcomes in multicenter and prospective studies are lacking.

Conclusion

It is difficult to continue PD alone with a declining RKF or when self-management is poor. Hence, combPDHD should be started to adjust the fluid volume, with adequate dialysis dose and peritoneal rest. This therapy is useful from a lifestyle viewpoint during the transition period from PD to HD and should not be continued indefinitely.

Clinical Factors Associated with Serum Magnesium Concentration in Patients Undergoing Peritoneal Dialysis: A Single-Center Observational Study

Purpose

Magnesium (Mg) is an essential element that is associated with various physiological functions, such as maintenance of blood pressure, muscle contraction, and nerve function. In patients undergoing hemodialysis, hypomagnesemia is associated with cardiovascular and all-cause mortality. However, in patients undergoing peritoneal dialysis (PD), clinical factors associated with Mg have not been fully investigated.

Patients and Methods

Clinical factors including anthropometric data, comorbidities, laboratory data, medications, and dialysis methods were collected from the medical records of patients undergoing PD. The associations of these factors with the serum Mg concentration were investigated by univariate and multivariate analyses.

Results

Sixty patients undergoing PD were investigated. The univariate analysis showed that the serum Mg concentration was significantly associated with treatment by hybrid PD (daily PD + once-weekly hemodialysis) (β = 0.264, P = 0.04), administration of phosphate binders (β = 0.294, P = 0.02), the serum C-reactive protein concentration (β = -0.318, P = 0.01), the serum potassium (K) concentration (β = 0.451, P < 0.01), and the serum intact parathormone concentration (β = -0.333, P = 0.01). The multivariate analysis using these factors showed an independent association between the serum Mg and K concentrations (β = 0.333, P = 0.01).

Conclusion

The serum Mg concentration was independently associated with the serum K concentration in patients undergoing PD.

Association between serum β2-microglobulin and mortality in Japanese peritoneal dialysis patients: A cohort study

Background

Higher serum β2-microglobulin (B2M) concentrations are associated with higher mortality in the general population, non-dialyzed chronic kidney disease patients and patients receiving hemodialysis (HD). However, this relationship among patients on peritoneal dialysis (PD) has not been validated.

Methods

We collected baseline data for 3,011 prevalent PD patients from a nationwide dialysis registry in Japan at the end of 2010. Clinical outcomes for 9 years were then evaluated using the registry at the end of 2011 to 2019. All-cause and cardiovascular (CV) mortality was assessed using Cox regression analysis and competing-risks regression analysis, respectively. We used multiple imputation to deal with missing covariate data.

Results

During a median follow-up of 87 months, 2,054 patients transferred to combined therapy with PD and HD or HD directly. A total of 3,011 patients, 1,235 (41.0%) died, including 437 patients (14.5%) from CV causes. Among them, 612 patients died after transfer to other dialysis modalities. Univariate analyses revealed no significant association between serum B2M and mortality, whereas higher serum B2M was independently associated with both all-cause and CV mortalities in adjusted models. However, the significant association between serum B2M and CV mortality disappeared in analysis treating serum B2M as a categorical variable. The effect of serum B2M on all-cause mortality was significantly higher among patients with higher urinary volume and a significant interaction was evident.

Conclusions

Using a large-scale registry, we found that serum B2M contributes tenuously but significantly to worse outcome and residual kidney function significantly affects this relationship. On the contrary, serum B2M per se had no predictive value for patient outcome in prevalent PD patients.

Association between lipid profile and residual renal function in incident peritoneal dialysis patients

INTRODUCTION

Residual renal function (RRF) is one of the most crucial factor in the management of peritoneal dialysis (PD). The aim of this study was to evaluate the association between lipid profile and preservation of RRF among incident PD patients.

METHODS

This retrospective cohort study investigated 113 patients (male, 72%; age, 59±14 years) who initiated PD between 2006 and 2017. We investigated the relationships between high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) at PD initiation and change in renal Kt/V during the first year after PD initiation.

RESULTS

Alterations in renal Kt/V during the first year after PD initiation correlated negatively with HDL-C at PD initiation, but not with LDL-C. On multivariate analysis, HDL-C at PD initiation was independently associated with change in renal Kt/V during the first year after PD initiation.

CONCLUSION

These results suggests importance of lipid management among incident PD patients for preservation of RRF.

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.

Change in Anemia by Carnitine Supplementation in Patients Undergoing Peritoneal Dialysis: A Retrospective Observational Study

Background: Carnitine supplementation improves various dialysis-related symptoms including erythropoietin-resistant anemia in patients who are undergoing hemodialysis. However, the utility of carnitine supplementation in patients who are undergoing peritoneal dialysis (PD) is not fully understood.

Methods: Thirteen patients undergoing PD [mean age: 54.2 ± 14.8 years, males: 9/13 (69%)] administered oral carnitine supplementation (mean dose: 9.1 ± 3.3 mg/kg/day) for 4–6 months were retrospectively investigated. Changes in serum carnitine levels and other clinical variables including the erythropoietin resistance index (ERI) were analyzed after carnitine supplementation.

Results: Carnitine supplementation increased serum total carnitine (48.5 ± 10.2 vs. 130.1 ± 37.2 μmol/L, P < 0.01), free carnitine (31.1 ± 8.3 vs. 83.1 ± 24.6 μmol/L, P < 0.01), and acyl carnitine (17.4 ± 2.8 vs. 46.9 ± 13.8, P < 0.01) levels. The acyl carnitine/free carnitine ratio was not affected (0.6 ± 0.1 vs. 0.6 ± 0.1, P = 0.75). Although the mean ERI was not affected by carnitine supplementation [13.7 ± 4.7 vs. 11.6 ± 3.4 IU/kg/(g/dL)/week, P = 0.28], the ERI change rate was significantly decreased (1.00 ± 0.00 vs. 0.87 ± 0.11, P < 0.01).

Conclusion: Carnitine supplementation may improve erythropoietin resistance in patients who are undergoing PD.

Risk Factors for Early Peritoneal Dialysis Discontinuation: Importance of Heart Failure

BACKGROUND

The number of patients on peritoneal dialysis (PD) in our hospital has increased during the past 5 years, but the number discontinuing PD has also increased. The purpose of this study was to identify the risk factors for PD discontinuation by analyzing the association between technical survival period (defined as the duration of PD) and various clinical factors.

METHODS

We retrospectively investigated 87 patients who were started on PD at our hospital and attended regularly from April 2015 to March 2020, and we analyzed the association between technical survival period and various clinical factors. We also looked for associations between technical survival period and hospitalizations for heart failure, peritonitis, and exit-site infections among patients undergoing PD.

RESULTS

The patients using renin-angiotensin-aldosterone system inhibitors (RASi) (P = 0.0218), those with left ventricular ejection fraction (LVEF) > 50% (P = 0.0194) when they started PD, and those with estimated glomerular filtration rate (eGFR) ≥ 6 (mL/ min/1.73m²) (P = 0.0013) at the initiation of PD showed significantly longer technical survival period, and those who were hospitalized for heart failure had significantly shorter period (P = 0.0008).

CONCLUSION

Treatment of RASi, LVEF > 50% and eGFR ≥ 6 mL/ min/1.73m² when the initiation of PD and better volume control to prevent ultrafiltration failure and heart failure may improve technical survival period in patients undergoing PD.

Comparisons of fatigue between dialysis modalities: A cross-sectional study

Background

Fatigue is one of the most frequent complications in dialyzed patients and is associated with poorer patient outcomes. Multiple factors are reported to be associated with fatigue development. Of them, the impacts of dialysis modalities remain unknown.

Methods

A total of 194 dialysis patients (mean age, 61±11 years; 134 males; modalities included hemodialysis (HD) in 26, online hemodiafiltration (HDF) in 74, peritoneal dialysis (PD) in 68, and combined therapy with PD and HD in 26 cases) were recruited for this cross-sectional study. Fatigue was assessed using the Profile of Mood States (POMS), a Visual Analogue Scale (VAS), and our original scale of fatigue, and depression was assessed by the Beck Depression Inventory-second edition (BDI-II). Our original scale of fatigue was administered both on dialysis and dialysis-free days to patients on HD and online HDF.

Results

The scores of the POMS, VAS, and our original scale were weakly but significantly inter-related (rho = 0.58, P<0.01; rho = 0.47, P<0.01, and rho = 0.42, P<0.01 between POMS and VAS, POMS and our original scale for fatigue, and VAS and our original scale for fatigue, respectively). The scores of these 3 tests showed no significant differences among the 4 modalities. On multivariate analysis, age, body mass index, creatinine, and employment status were associated with the presence or severity of fatigue, whereas dialysis modality was not. A similar result was obtained in 122 patients without depression. The prevalence of fatigue by our original scale was significantly lower on dialysis-free days than on dialysis days in patients on HD and online HDF.

Conclusions

The results suggest that there is no significant association between different dialysis modalities including HD, online HDF, PD and combined therapy with PD and HD and the prevalence or severity of fatigue.

Serum Zinc Concentration Correlates With Ferritin Concentration in Patients Undergoing Peritoneal Dialysis: A Cross-Sectional Study

Background: Zinc deficiency is common and is associated with erythropoietin resistant anemia, dysgeusia, and hypogonadism in patients undergoing hemodialysis. However, the prevalence and clinical effects of zinc deficiency in patients undergoing peritoneal dialysis (PD) have not been determined. Methods: This was a retrospective, cross-sectional study. The prevalence of serum zinc deficiency and the clinical factors related to serum zinc concentration were determined in 49 patients undergoing PD [mean age 59.5 years (±14.8 years), 38/49 were men (78.6%), median PD period 24.0 months (12.5-45.0 months)]. A serum zinc concentration <60 μg/dL was defined as serum zinc deficiency, and a serum zinc concentration between 60 and 80 μg/dL as possible serum zinc deficiency. Results: Serum zinc deficiency was present in 51% (25/49) of the patients, and possible serum zinc deficiency was present in 45% (22/49) of patients undergoing PD. Multivariate analysis showed that serum zinc concentration significantly correlated with serum ferritin concentration (β = 0.357, P < 0.01). Conclusions: The prevalences of serum zinc deficiency and possible serum deficiency are high and serum zinc concentration correlates with serum ferritin concentration in patients undergoing PD.

Factors affecting the relationship between ionized and corrected calcium levels in peritoneal dialysis patients: a retrospective cross-sectional study

BACKGROUND

Chronic kidney disease-mineral and bone disorder (CKD-MBD) management in patients with end-stage renal disease is important owing to the risk of cardiovascular diseases. In clinical practice, we manage patients not by monitoring the levels of biologically active ionized calcium (iCa) but by monitoring total serum calcium or corrected calcium (cCa). We previously reported that iCa/cCa ratio was different between patients with hemodialysis and those with peritoneal dialysis (PD). In PD patients, several factors are expected to affect iCa/cCa ratio. Therefore, modifying the strategy to achieve better CKD-MBD management might be necessary; however, no reports have studied this to date. Therefore, we investigated the factors influencing iCa/cCa ratio in PD patients.

METHODS

This retrospective cross-sectional study examined background and laboratory data, including iCa, collected at routine outpatient visits. The patients were divided into the first, second, and third tertile of iCa/cCa ratio groups to compare patient background and laboratory data. Multiple regression analysis was used to investigate the factors influencing iCa/cCa ratio. We used multiple imputation to deal with missing covariate data.

RESULTS

In total, 169 PD patients were enrolled. In PD patients with lower iCa/cCa ratio, PD duration was longer and pH was higher. Urine volume and weekly renal Kt/V were lower in the patients with lower iCa/cCa ratio than in those with higher iCa/cCa ratio. iCa/cCa ratio and weekly renal Kt/V were directly correlated (r = 0.41, p < 0.01), and weekly renal Kt/V and pH were independent factors affecting iCa/cCa ratio (t = 2.86, p < 0.01 and t = - 5.42, p < 0.01, respectively).

CONCLUSIONS

iCa levels were lower in PD patients with lower residual renal function (RRF) even though their cCa levels were equal to those with maintained RRF, warranting caution in the assessment and management of CKD-MBD in PD patients.

Prevalence of Zinc Deficiency in Japanese Patients on Peritoneal Dialysis: Comparative Study in Patients on Hemodialysis

BACKGROUND

It is known that patients on hemodialysis (HD) are prone to developing zinc deficiency due to removal of zinc by HD, inadequate dietary intake, and reduced gastrointestinal zinc absorption. However, the prevalence of zinc deficiency in patients on peritoneal dialysis (PD) has not been well established.

METHODS

Serum zinc levels were compared between 47 patients on PD and 47 patients on HD matched for age, sex, and duration of dialysis. A serum zinc level < 60 μg/dL was defined as clinical zinc deficiency and a level of 60-80 μg/dL as subclinical zinc deficiency. The prevalence of zinc deficiency and associated clinical factors were determined in both groups.

RESULTS

Clinical zinc deficiency was found in 59.6% of the PD group and 70.2% of the HD group (p = 0.391). Subclinical zinc deficiency was found in 40.4% of the PD group and 29.8% of the HD group. Age, body mass index, and serum albumin level were identified as independent predictors of zinc deficiency in the PD group by multivariate analysis.

CONCLUSIONS

A higher prevalence of clinical and subclinical zinc deficiency was found in patients on PD. The rates were comparable between patients on PD and those on HD after adjustment for confounding factors.

International comparison of peritoneal dialysis prescriptions from the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS)

Background:

We describe peritoneal dialysis (PD) prescription variations among Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) participants on continuous ambulatory PD (CAPD) and automated PD (APD; n = 4657) from Australia/New Zealand (A/NZ), Canada, Japan, Thailand, United Kingdom (UK), and United States (US).

Results:

CAPD was more commonly used in Thailand and Japan, while APD predominated over CAPD in A/NZ, Canada, the US, and the UK. Total prescribed PD volume normalized to the surface area was the highest in Thailand and the lowest in Japan (for both APD and CAPD) and the UK (for CAPD). PD patients from Thailand had the lowest residual urine volume and residual renal urea clearance, yet achieved the highest dialysis urea clearance. Japanese patients had the lowest dialysis urea clearances for both APD and CAPD. Despite having similar urine volumes to patients in A/NZ, Canada, Japan, and the UK, US CAPD and APD patients used 2.5% and 3.86% glucose PD solutions more frequently, whereas fewer than 25% of these patients used icodextrin. Over half of the patients in A/NZ, Canada, the UK, and Japan used icodextrin, whereas it was hardly used in Thailand. Japan and Thailand were more likely to use 1.5% glucose solutions for their PD prescription.

Conclusions:

There are considerable international variations in PD modality use and prescription patterns that translate into important differences in achieved dialysis clearances. Ongoing recruitment of additional PDOPPS participants and accrual of follow-up time will allow us to test the associations between specific PD prescription regimens and clinical and patient-reported outcomes.

Association between carnitine deficiency and the erythropoietin resistance index in patients undergoing peritoneal dialysis: a cross-sectional observational study

Carnitine deficiency contributes to developing various pathological conditions, such as cardiac dysfunction, muscle weakness, and erythropoietin-resistant anemia in patients undergoing hemodialysis. However, a conclusion has not been reached concerning the prevalence and the effect of carnitine deficiency in patients undergoing peritoneal dialysis (PD). In this study, the prevalence of carnitine deficiency and the clinical factors associated with carnitine deficiency were investigated in 60 patients undergoing PD. The median age of the patients was 62.5 years (52.5–72.5 years), the proportion of male sex was 44/60 (73.3%), and the median PD period was 24 months (12–45 months). Carnitine deficiency (acyl carnitine/free carnitine ratio >0.4) was detected in 56/60 (93%) patients. Multiple regression analysis showed that the erythropoietin resistance index was independently associated with carnitine deficiency (β = 0.283, p = 0.04). These results suggest that carnitine plays pivotal roles in hematogenesis in patients undergoing PD.

Successful Peritoneal Dialysis for the Treatment of Inotrope-Dependent End-Stage Heart Failure

Extra- and/or intracorporeal renal replacement therapy can improve the cardiorenal hemodynamics in patients with advanced heart failure (HF) refractory to medical therapy and renal failure. Here, we report the case of a 51-year-old woman with inotrope-dependent end-stage HF and chronic renal failure due to anthracycline-induced cardiomyopathy, in whom the induction of hemodiafiltration and subsequent chronic peritoneal dialysis (PD) provided a dramatic improvement of her cardiac hemodynamics from restrictive to almost normal physiology assessed by echocardiography and cardiac catheterization. The patient returned to office work with New York Heart Association functional class I-II symptoms for at least 3 years with continuous ambulatory PD after hospital discharge.

Association of Lower Serum Bilirubin With Loss of Residual Kidney Function in Peritoneal Dialysis Patients

Bilirubin is recognized as an endogenous antioxidant, and low serum bilirubin is reported to be associated with the progression of kidney disease. However, it is unclear whether serum bilirubin levels are associated with the loss of residual kidney function (RKF) in peritoneal dialysis (PD) patients. This study investigated the relationship between serum total bilirubin and loss of RKF. We prospectively followed 94 PD patients who started PD in our hospital between June 2006 and May 2016. Ten patients who had chronic liver disease or cirrhosis were excluded. Patients were divided into three groups based on serum total bilirubin concentration tertiles: tertile 1 (T1) < 0.3, T2 = 0.3, and T3 ≥ 0.4 mg/dL. We estimated the relationship between serum bilirubin and loss of RKF, defined as daily urine volume (<100 mL) within 3 years after starting PD, using a Cox proportional hazards model. During the 3-year observation period, 22 patients lost RKF. The incidence rate of loss of RKF increased linearly with the decrease in serum total bilirubin levels (P for trend < 0.05). After adjusting for confounding factors, low serum total bilirubin level was shown to be an independent predictor of loss of RKF (hazard ratio [HR] for every 0.1 mg/dL decrease, 1.50; 95% confidence interval [CI], 1.01-2.51; HR [95%CI] for T2 and T1 [vs. T3] 2.03 [0.65-7.88] and 3.70 [1.00-15.9]). This study suggests that low serum total bilirubin levels are associated with the loss of RKF in PD patients.

Association of B-Type Natriuretic Peptide Level With Residual Kidney Function in Incident Peritoneal Dialysis Patients

BACKGROUND

Residual kidney function (RKF) is an important factor influencing both technique and patient survival in peritoneal dialysis (PD) patients. B-type natriuretic peptide (BNP) is considered a marker of cardio-renal syndrome. The relationship between BNP and RKF in PD patients remains unclear.

METHODS

We conducted a prospective study of 89 patients who had started and continued PD for 6 months or more in Kyushu University Hospital between June 2006 and September 2015. Participants were divided into low BNP (≤ 102.1 ng/L) and high BNP (> 102.1 ng/L) groups according to median plasma BNP level at PD initiation. The primary outcome was RKF loss, defined as 24-hour urine volume less than 100 mL. We estimated the association between BNP and RKF loss using a Kaplan-Meier method and Cox proportional hazards model and compared the rate of RKF decline between the 2 groups. To evaluate the consistency of the association, we performed subgroup analysis stratified by baseline characteristics.

RESULTS

During the median follow-up of 30 months, 30 patients lost RKF. Participants in the high BNP group had a 5.87-fold increased risk for RKF loss compared with the low BNP group after adjustment for clinical and cardiac parameters. A high plasma BNP level was more clearly associated with RKF loss in younger participants compared with older participants in subgroup analysis.

CONCLUSIONS

B-type natriuretic peptide may be a useful risk marker for RKF loss in PD patients. The clinical importance of plasma BNP level as a marker of RKF loss might be affected by age.

Biocompatibility of a new PD solution for Japan, Reguneal™, measured as in vitro proliferation of fibroblasts

BACKGROUND

The aim of this study was to investigate in vitro biocompatibility of Reguneal™, a new bicarbonate containing peritoneal dialysis fluid (PDF) for Japan, and compare it with other PDFs available in that country.

METHODS

We assessed basal cytotoxicity using in vitro proliferation of cultured fibroblasts, L-929, determining the quantity of living cells by the uptake of Neutral Red. Levels of ten glucose degradation products (GDPs) were measured by a validated ultrahigh-performance liquid chromatography method in combination with an ultraviolet detector. We compared inhibition of fibroblast cell growth between brands of PDF, adjusting for dextrose and GDP concentrations using random-effects mixed models.

RESULTS

The results demonstrate that cytotoxicity of Reguneal™ is comparable to a sterile-filtered control and is less cytotoxic than most of the other PDFs, most of which significantly inhibited cell growth. As a "class effect", increasing dextrose and GDP concentrations were non-significantly but positively associated with cytotoxicity. As a "brand effect", these relationships varied widely between brands, and some PDFs had significant residual effects on basal cytotoxicity through mechanisms that were unassociated with either dextrose or GDP concentration.

CONCLUSION

Our study suggests that Reguneal™ is a biocompatible PDF. The results of our study also highlight that dextrose and GDPs are important for biocompatibility, but alone are not a complete surrogate. The results of our study need to be confirmed in other tissue culture models, and should lead to further research on determinants of biocompatibility and the effect of such PDFs on clinical outcomes.

After peritoneal dialysis discontinuation: When will we remove peritoneal dialysis catheter?

Most of the peritoneal dialysis patients stop their peritoneal dialysis therapy and transfer to hemodialysis or kidney transplantation. In Japan, most end-stage kidney disease patients select hemodialysis after peritoneal dialysis discontinuation. Peritoneal dialysis catheter will be removed after stopping peritoneal dialysis. If peritoneal dialysis patients suffer from refractory peritonitis or severe tunnel infection, we remove the peritoneal dialysis catheter immediately. However, the causes of peritoneal dialysis discontinuation are ultrafiltration failure or peritoneal membrane dysfunction, and we have to consider the timing of peritoneal dialysis catheter removal. Encapsulating peritoneal sclerosis is the most important adverse event of peritoneal dialysis. And encapsulating peritoneal sclerosis often develops after stopping peritoneal dialysis. Risk factors associated with encapsulating peritoneal sclerosis are high peritoneal equilibration test values, longer peritoneal dialysis period, frequent peritonitis, and so on. There is no evidence to prevent encapsulating peritoneal sclerosis completely. Therefore, we can preserve the peritoneal dialysis catheter and assess the changes of peritoneal function after peritoneal dialysis discontinuation, if patient is suspected to have high risk of encapsulating peritoneal sclerosis.

Serum Endocan as a Predictive Marker for Decreased Urine Volume in Peritoneal Dialysis Patients

Background

Endocan is expressed in vascular endothelial cells, and its expression is enhanced following endothelial injury via inflammatory cytokines. Subsequently, endocan is secreted into the circulation. Thus, serum endocan levels are considered a marker of endothelial injury. However, to the best of our knowledge, no data on the serum endocan levels in peritoneal dialysis (PD) patients are available.

Material/Methods

This study included 21 PD patients who underwent peritoneal equilibration test (PET) more than once between 2011 and 2015. Serum samples were collected from each patient, and the 24-h urine volume was measured at the time of PET. Serum endocan levels were measured using enzyme-linked immunosorbent assay (ELISA) at the time of the first PET, and their relationship with clinical data or the extent of urine volume decline (mL/year) was analyzed retrospectively.

Results

Serum endocan levels were positively correlated with proteinuria level, serum creatinine level, serum tumor necrosis factor (TNF)-α level, β₂-microglobulin level, and PD drainage volume, but not with urine volume at baseline. The extent of decline in urine volume was significantly associated with serum endocan level, proteinuria level, serum creatinine level, and serum TNF-α level at baseline in a simple linear regression analysis. Moreover, multiple linear regression analysis showed that the serum endocan level and proteinuria level at baseline were independent predictors for the extent of decline in urine volume.

Conclusions

The results of this study indicate that serum endocan level and proteinuria level may be useful predictive markers for decreased urine volume in PD patients.

Recommendations for pathological diagnosis on biopsy samples from peritoneal dialysis patients

Peritoneal dialysis (PD) has been established as an essential renal replacement therapy for patients with end stage renal disease during the past half century. Histological evaluation of the peritoneal membrane has contributed to the pathophysiological understanding of PD-related peritoneal injury such as peritonitis, fibrosis, and encapsulating peritoneal sclerosis (EPS). Hyalinizing peritoneal sclerosis (HPS), also known as simple sclerosis, is observed in almost all of PD patients. HPS is morphologically characterized by fibrosis of the submesothelial interstitium and hyalinizing vascular wall, particularly of the post-capillary venule (PCV). Two histological factors, the thickness of submesothelial compact zone (SMC) and the lumen/vessel ratio (L/V) at the PCV, have been used for the quantitative evaluation of HPS. The measuring system on SMC thickness and L/V ratio is easy and useful for evaluating the severity of HPS. On the other hand, EPS is characterized by unique encapsulation of the intestines by an "encapsulating membrane". This newly formed membranous structure covers the visceral peritoneum of the intestines, which contains fibrin deposition, angiogenesis, and proliferation of fibroblast-like cells and other inflammatory cells. This review will cover the common understandings of PD-related peritoneal alterations and provide a basic platform for clinical applications and future studies in this field.

Factors Associated with the Serum Myostatin Level in Patients Undergoing Peritoneal Dialysis: Potential Effects of Skeletal Muscle Mass and Vitamin D Receptor Activator Use

Myostatin is a member of the transforming growth factor-β family, which regulates synthesis and degradation of skeletal muscle proteins and is associated with the development of sarcopenia. It is up-regulated in the skeletal muscle of chronic kidney disease patients and is considered to be involved in the development of uremic sarcopenia. However, serum myostatin levels have rarely been determined, and the relationship between serum myostatin levels with clinical and metabolic factors remains unknown. This cross-sectional study investigated the association between serum myostatin level and clinical factors in 69 outpatients undergoing peritoneal dialysis. Serum myostatin level was determined by commercially available enzyme-linked immunosorbent assay (ELISA). Univariable and multivariable analysis were conducted to determine factors associated with serum myostatin levels. The factors included age, sex, diabetes mellitus, dialysis history, body mass index, residual kidney function, peritoneal dialysate volume, serum biochemistries, and the use of vitamin D receptor activators (VDRAs). Mean serum myostatin level was 7.59 ± 3.37 ng/mL. There was no association between serum myostatin level and residual kidney function. Serum myostatin levels were significantly and positively associated with lean body mass measured by the creatinine kinetic method and negatively associated with the use of VDRAs after adjustment for potential confounding factors. Our study indicated that serum myostatin levels are associated with skeletal muscle mass and are lower in patients treated with VDRAs. Further studies are necessary to determine the significance of measuring serum myostatin level in patients undergoing peritoneal dialysis.

Factors associated with serum soluble inhibitors of Wnt-β-catenin signaling (sclerostin and dickkopf-1) in patients undergoing peritoneal dialysis

AIM

Sclerostin and dickkopf-1 (Dkk-1) are soluble inhibitors of Wnt-β-catenin signaling and are involved in decreased bone formation and bone volume in patients with various bone diseases. The clinical characteristics of sclerostin and Dkk-1 and their impacts on mineral and bone metabolism remain undetermined in patients undergoing peritoneal dialysis (PD).

METHODS

This cross-sectional study investigated the association between serum sclerostin and Dkk-1 levels and mineral disorders in 74 outpatients under PD treatment. Levels of sclerostin and Dkk-1 in serum, urine, and peritoneal dialysate were determined using enzyme-linked immunosorbent assay kits. The associations between serum sclerostin and Dkk-1 levels and biochemical parameters were evaluated by linear regression analyses.

RESULTS

Median serum sclerostin and Dkk-1 levels were 138 pmol/L (range, 98.3-195.9 pmol/L) and 38.8 pmol/L (range, 28.5-47.1 pmol/L), respectively. Both sclerostin and Dkk-1 were excreted into urine and peritoneal dialysate. Multivariable linear regression analyses showed that serum sclerostin level was significantly associated with age, sex, parathyroid hormone level, and renal Kt/V. In contrast, serum Dkk-1 level was associated with platelet count and serum fibroblast growth factor 23 level but not with any of the bone metabolic markers.

CONCLUSION

Serum sclerostin was associated with serum intact parathyroid hormone, while Dkk-1 was associated with serum fibroblast growth factor 23 in patients undergoing PD. The utility of determining soluble Wnt-β-catenin inhibitors levels in patients undergoing PD requires further investigation.

Matrix metalloproteinase-2 as a superior biomarker for peritoneal deterioration in peritoneal dialysis

AIM: To investigate the efficacy of effluent biomarkers for peritoneal deterioration with functional decline in peritoneal dialysis (PD).

METHODS: From January 2005 to March 2013, the subjects included 218 PD patients with end-stage renal disease at 18 centers. Matrix metalloproteinase-2 (MMP-2), interleukin-6 (IL-6), hyaluronan, and cancer antigen 125 (CA125) in peritoneal effluent were quantified with enzyme-linked immunosorbent assay. Peritoneal solute transport rate was assessed by peritoneal equilibration test (PET) to estimate peritoneal deterioration.

RESULTS: The ratio of the effluent level of creatinine (Cr) obtained 4 h after injection (D) to that of plasma was correlated with the effluent levels of MMP-2 (ρ = 0.74, P < 0.001), IL-6 (ρ = 0.46, P < 0.001), and hyaluronan (ρ = 0.27, P < 0.001), but not CA125 (ρ = 0.13, P = 0.051). The area under receiver operating characteristic curve for the effluent levels of MMP-2, IL-6, and hyaluronan against high PET category were 0.90, 0.78, 0.62, and 0.51, respectively. No patient developed new-onset encapsulating peritoneal sclerosis for at least 1.5 years after peritoneal effluent sampling.

CONCLUSION: The effluent MMP-2 level most closely reflected peritoneal solute transport rate. MMP-2 can be a reliable indicator of peritoneal deterioration with functional decline.

Effluent Tenascin-C Levels Reflect Peritoneal Deterioration in Peritoneal Dialysis: MAJOR IN PD Study

Peritoneal deterioration causing structural changes and functional decline is a major complication of peritoneal dialysis (PD). The aim of this study was to explore effluent biomarkers reflecting peritoneal deterioration. In an animal study, rats were intraperitoneally administered with PD fluids adding 20 mM methylglyoxal (MGO) or 20 mM formaldehyde (FA) every day for 21 days. In the MGO-treated rats, tenascin-C (TN-C) levels in the peritoneal effluents were remarkably high and a cluster of TN-C-positive mesothelial cells with epithelial-to-mesenchymal transition- (EMT-) like change excessively proliferated at the peritoneal surface, but not in the FA-treated rats. Effluent matrix metalloproteinase-2 (MMP-2) levels increased in both the MGO- and FA-treated rats. In a clinical study at 18 centers between 2006 and 2013, effluent TN-C and MMP-2 levels were quantified in 182 PD patients with end-stage renal disease. Peritoneal function was estimated using the peritoneal equilibration test (PET). From the PET results, the D/P Cr ratio was correlated with effluent levels of TN-C (ρ = 0.57, p < 0.001) and MMP-2 (ρ = 0.73, p < 0.001). We suggest that TN-C in the effluents may be a diagnostic marker for peritoneal deterioration with EMT-like change in mesothelial cells in PD.

Causes of death in patients with childhood-onset type 1 diabetes receiving dialysis in Japan: Diabetes Epidemiology Research International (DERI) Mortality Study

AIMS

To investigate the causes of death and how they changed over time in patients with childhood-onset type 1 diabetes who were receiving dialysis.

METHODS

Of the 1384 patients who were diagnosed with type 1 diabetes at<18 years of age between 1965 and 1979, 113 who were subsequently confirmed as having received dialysis and having died as of January 1, 2008 were found eligible for the study. The cause of death trends were expressed according to the duration of dialysis.

RESULTS

The leading causes of death were end-stage renal disease (ESRD) (36.3%), cardiovascular disease (CVD) (31.9%), and infections (20.3%). Among CVD, cerebral hemorrhage was the most frequent (38.9%) and showed a significant trend for an increase in the duration of dialysis (P=0.01, the Cochran-Armitage trend test). The mortality from ESRD concentrated within 5 years of dialysis and that from CVD increased after 10 years of dialysis, while the mortality from infections peaked during 5 to 10 years from initiation of dialysis.

CONCLUSIONS

The leading causes of death in dialysis patients with type 1 diabetes were ESRD, CVD, and infections. As the duration of dialysis increased, however, CVD contributed more to mortality. Special attention should be paid to CVD, particularly cerebral hemorrhage, to improve the long-term prognosis of patients.

Japanese society for dialysis therapy renal data registry-a window through which we can view the details of Japanese dialysis population

The Japanese Society for Dialysis Therapy (JSDT) collects the clinical data from all the facilities to create a nation-wide registry system named JSDT Renal Data Registry (JRDR). This survey was begun in 1966 as a form of facility survey. Patient survey started in 1983. More than 95% of facilities respond to the survey on the basis of voluntary work of facility staffs. Therefore, JRDR has the longest history and the most comprehensive coverage. As for the prevalent patients, 304,856 patients are treated by dialysis therapy in Japan as of the year 2011. The demographics of the Japanese dialysis population have been markedly changing in terms of age, primary diagnoses and dialysis vintage. The mean age of prevalent population reaches 66.55 years at the end of 2011. The increase in the numbers of dialysis population is due to the growth of those older than 65 years old. Patients with the vintage longer than 20 years account for 8% of the entire population. Around 38 thousands patients started their dialysis treatments, whereas 31 thousands deceased. The disease burden of cardiovascular diseases as well as infection is substantial due to the demographic changes. Many evidences have been reported from the data obtained from JRDR to date. These findings covers a wide range of dialysis practice and are utilized for the development of JSDT guidelines. Therefore, JRDR has provided indispensable and fundamental data of Japanese dialysis population.

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

Multidisciplinary clinical strategies for encapsulating peritoneal sclerosis in peritoneal dialysis: update from Japan

Peritoneal dialysis is established as a first-line standard renal replacement therapy for end-stage renal disease. However, the development of encapsulating peritoneal sclerosis has been a critical complication among long-term peritoneal dialysis patients. During the past decade, multidisciplinary approaches have been used to suppress encapsulating peritoneal sclerosis. The present article reviews the historical and present status of encapsulating peritoneal sclerosis in Japan.

Relationship between residual renal function and serum fibroblast growth factor 23 in patients on peritoneal dialysis

Fibroblast growth factor 23 (FGF23) levels in dialysis patients are influenced by various factors, including phosphorus load. However, the clinical parameters that determine serum FGF23 levels in patients on peritoneal dialysis (PD) remain unclear. The aim of the present study was to examine the effects of clinical factors, on serum FGF23 levels, with an emphasis on residual renal function (RRF). This cross-sectional study included 56 outpatients undergoing PD therapy. Urine volume ≥ 100 mL/day or renal creatinine (Cr) clearance was used as a surrogate marker for RRF. Clinical characteristics were compared between patients with and without RRF. Linear regression analysis was conducted with serum FGF23 level as the dependent variable and renal Cr clearance as the main independent variable. The median and interquartile range of serum FGF23 levels were 5970 (1451-11,688) pg/mL. Patients with RRF showed higher urinary and total phosphate eliminations, and lower serum FGF23 and phosphate levels than patients without RRF. Multivariate linear regression analysis showed that the renal Cr clearance and serum phosphate and dialysis history were negatively associated with serum FGF23 levels, even after adjusting for potential confounders including peritoneal Cr clearance. Further, the predictabilities of serum FGF23 were comparable among renal Cr clearance, Kt/V for urea, and renal phosphate clearance. RRF determined by renal Cr clearance or residual urine volume is an independent negative determinant of serum FGF23 levels in PD patients.

Encapsulating peritoneal sclerosis in the era of a multi-disciplinary approach based on biocompatible solutions: the NEXT-PD study

INTRODUCTION

Encapsulating peritoneal sclerosis (EPS) is a serious complication of peritoneal dialysis (PD). Over the past decade in Japan, a multidisciplinary approach has been adopted to minimize the incidence and improve outcomes of EPS. This strategy includes planned PD discontinuation for high-risk patients and the introduction of biocompatible solutions. This study examined the current clinical status of EPS in representative PD centers in Japan.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

Patients (n = 1,338) from 55 PD centers in Japan who were using neutral-pH solutions from the initiation of therapy (mean age, 62 years; median PD duration, 32 months; concomitant use of icodextrin, 35.2%; PD and hemodialysis combination therapy, 12.2%) were assessed every 6 months to ascertain the reasons for PD discontinuation and the development of EPS development. Outcomes were also recorded. The study period was from November 2008 to March 2012.

RESULTS

There were 727 patients who discontinued PD, including 163 deaths. Among all causes of PD withdrawal except for death, planned PD discontinuation to avoid EPS was utilized in 58 cases (7.1% in total). The strategy was increasingly utilized in proportion to the duration of PD: 0.5% for patients undergoing PD for < 3 years, 0.6% for patients undergoing PD for 5 years, 14.7% for patients undergoing PD for 8 years, and 35.5% for patients undergoing PD for > 8 years. Fourteen patients developed EPS (three cases after PD), which corresponded with an overall incidence of 1.0%. The incidence according to the duration of PD was 0.3% for PD < 3 years, 0.6% for PD = 5 years, 2.3% for PD = 8 years, and 1.2% for PD > 8 years. In terms of therapy, 11 patients were treated with prednisolone (PSL), and surgical enterolysis was utilized in two cases. Complete remission of abdominal symptoms was achieved in twelve patients (85.7%), and three died due to EPS (mortality rate of 21.4%).

CONCLUSIONS

Use of the multidisciplinary approach described above reduces the risk of the development of EPS according to PD duration. In cases of de novo EPS cases in Japan, this strategy can also attenuate the clinical course of the condition.

Relationship between Icodextrin use and decreased level of small low-density lipoprotein cholesterol fractioned by high-performance gel permeation chromatography

Background

Because of the absorption of glucose in peritoneal dialysis (PD) solution, PD patients show an atherogenic lipid profile, which is predictive of poor survival in PD patients. Lipoprotein subclasses consist of a continuous spectrum of particles of different sizes and densities (fraction). In this study, we investigated the lipoprotein fractions in PD patients with controlled serum low-density lipoprotein (LDL) cholesterol level, and evaluated the effects of icodextrin on lipid metabolism.

Methods

Forty-nine PD patients were enrolled in this cross-sectional study in Japan. The proportions of cholesterol levels to total cholesterol level (cholesterol proportion) in 20 lipoprotein fractions were measured using an improved method of high-performance gel permeation chromatography (HPGPC).

Results

Twenty-six patients used icodextrin. Although no significant differences in cholesterol levels in LDL and high-density lipoprotein (HDL) were observed between the patients using icodextrin (icodextrin group) and control groups, HPGPC showed that the icodextrin group had significantly lower cholesterol proportions in the small LDL (t-test, p=0.053) and very small LDL (p=0.019), and significantly higher cholesterol proportions in the very large HDL and large HDL than the control group (p=0.037; p=0.066, respectively). Multivariate analysis adjusted for patient characteristics and statin use showed that icodextrin use was negatively associated with the cholesterol proportions in the small LDL (p=0.037) and very small LDL (p=0.026), and positively with those in the very large HDL (p=0.040), large HDL (p=0.047), and medium HDL (p=0.009).

Conclusions

HPGPC showed the relationship between icodextrin use and the cholesterol proportions in lipoprotein fractions in PD patients. These results suggest that icodextrin may improve atherogenic lipid profiles in a manner different from statin.

The association of very-low-density lipoprotein with ankle-brachial index in peritoneal dialysis patients with controlled serum low-density lipoprotein cholesterol level

Background

Peripheral artery disease (PAD) represents atherosclerotic disease and is a risk factor for death in peritoneal dialysis (PD) patients, who tend to show an atherogenic lipid profile. In this study, we investigated the relationship between lipid profile and ankle-brachial index (ABI) as an index of atherosclerosis in PD patients with controlled serum low-density lipoprotein (LDL) cholesterol level.

Methods

Thirty-five PD patients, whose serum LDL cholesterol level was controlled at less than 120mg/dl, were enrolled in this cross-sectional study in Japan. The proportions of cholesterol level to total cholesterol level (cholesterol proportion) in 20 lipoprotein fractions and the mean size of lipoprotein particles were measured using an improved method, namely, high-performance gel permeation chromatography. Multivariate linear regression analysis was adjusted for diabetes mellitus and cardiovascular and/or cerebrovascular diseases.

Results

The mean (standard deviation) age was 61.6 (10.5) years; PD vintage, 38.5 (28.1) months; ABI, 1.07 (0.22). A low ABI (0.9 or lower) was observed in 7 patients (low-ABI group). The low-ABI group showed significantly higher cholesterol proportions in the chylomicron fraction and large very-low-density lipoproteins (VLDLs) (Fractions 3–5) than the high-ABI group (ABI>0.9). Adjusted multivariate linear regression analysis showed that ABI was negatively associated with serum VLDL cholesterol level (parameter estimate=-0.00566, p=0.0074); the cholesterol proportions in large VLDLs (Fraction 4, parameter estimate=-3.82, p=0.038; Fraction 5, parameter estimate=-3.62, p=0.0039) and medium VLDL (Fraction 6, parameter estimate=-3.25, p=0.014); and the size of VLDL particles (parameter estimate=-0.0352, p=0.032).

Conclusions

This study showed that the characteristics of VLDL particles were associated with ABI among PD patients. Lowering serum VLDL level may be an effective therapy against atherosclerosis in PD patients after the control of serum LDL cholesterol level.

The clinical utility of serum tartrate-resistant acid phosphatase 5b in the assessment of bone resorption in patients on peritoneal dialysis

OBJECTIVES

Serum tartrate-resistant acid phosphatase 5b (TRACP5b) is a bone resorption marker used in the assessment of bone metabolic status. The present study was designed to determine the clinical characteristics and utility of measuring serum TRACP5b levels in peritoneal dialysis (PD) patients.

DESIGN

Cross-sectional study.

PATIENTS

Forty-one patients receiving PD treatment in a single centre.

MEASUREMENT

Serum levels of the bone turnover markers TRACP5b, N-terminal cross-linking telopeptide of type 1 collagen (NTX), bone-specific alkaline phosphatase (BAP), and parathyroid hormone (PTH) were simultaneously measured. The correlation of serum TRACP5b with other established bone markers was analysed after logarithmic transformation. Multivariate linear regression analysis was performed to examine the effects of both renal and peritoneal Kt/V (an index for solute clearance) for urea on bone markers using age, sex, body mass index, and PTH as covariates. Bone markers were also measured in three patients before and after treatment with cinacalcet hydrochloride, alphacalcidol, and raloxifene hydrochloride.

RESULTS

Log TRACP5b was significantly correlated with log NTX, log BAP and log PTH. In the multivariate analysis, peritoneal Kt/V was not correlated with log NTX, log BAP or log TRACP5b. In contrast, renal Kt/V was significantly correlated with log NTX only. Responses to drug treatment were more accurately determined from serum TRACP5b and BAP than from serum NTX.

CONCLUSIONS

Serum TRACP5b and BAP are potentially useful biomarkers for the evaluation of bone turnover in PD patients because they correlate well with other established bone markers and they are not influenced by renal and peritoneal clearances.