Peritoneal dialysis--current status and future challenges

[Neuropsychological impairments in patients undergoing peritoneal dialysis treatment]

BACKGROUND

Patients with chronic kidney disease on hemodialysis (HD) often have cognitive deficits. However, there are few studies that have examined the neuropsychological impairments of patients receiving peritoneal dialysis (PD).

METHODS

Executive functions, processing speed and verbal memory were assessed in 27 PD patients, 42 HD patients, and 42 healthy participants (HP). Systolic blood pressure and total time on renal replacement therapy (RRT) were controlled statistically. Associations between performance and clinical factors were analyzed using correlations and multiple regression.

RESULTS

The DP group showed better performance compared to the HD group in verbal fluency, working memory, cognitive flexibility, planning and decision making. The DP group showed worse execution than the HP group in verbal inhibition and memory. Executive function scores were positively associated with total months on PD, total months on RRT, total months on HD, albumin, total cholesterol, and phosphorus, and negatively with ferritin.

CONCLUSION

Global executive functioning was more optimal in PD patients than in HD patients. The results show the positive effect of PD on executive functions, which must be taken into account when choosing the TRS. The associations observed between biochemical factors and performance show the importance of maintaining an adequate nutritional status in these patients.

The Point-of-Care Peritoneal Dialysis System Early Evaluation Study (POC-PDEE): A pilot proof-of-principal study of the Ellen Medical Devices Point-of-Care affordable peritoneal dialysis system

The global unmet need for kidney replacement therapy means that millions of people die every year as they cannot afford treatment. Peritoneal dialysis (PD) offers comparable survival to haemodialysis and is often more affordable, but one barrier to increasing access is that conventional manufacturing and distribution of PD fluid is costly. Here we report the results from a pilot proof-of-principal study demonstrating for the first time that the Ellen Medical Devices Point-of-Care system can be used by patients to produce sterile PD fluid at the point-of-care. With further development, this low-cost system could offer a solution to the many millions of people around the world who currently cannot afford treatment for kidney failure.

An update on absolute and relative indications for dialysis treatment modalities

Background

Choosing a dialysis modality is an important decision for people to make as their kidney failure progresses. In doing so, their options should be informed by any absolute or relative indications that may favour one modality over another.

Methods

In creating this update, we reviewed literature using a framework that considered first, high-level outcomes (survival and modality transition) from large registry data and cohort studies when considering optimal patient pathways; second, factors at a dialysis provider level that might affect relative indications; and third, specific patient-level factors. Both main types of dialysis modality, peritoneal (PD) and haemodialysis (HD), and their subtypes were considered.

Results

For most people starting dialysis, survival is independent of modality, including those with diabetes. Better survival is seen in those with less comorbidity starting with PD or home HD, reflecting continued improvements over recent decades that have been greater than improvements seen for centre HD. There are provider-level differences in the perceived relative indications for home dialysis that appear to reflect variability in experience, prejudice, enthusiasm, and support for patients and carers. Absolute contraindications are uncommon and, in most cases, where modality prejudice exists, e.g. obesity, Adult Polycystic Kidney Disease, and social factors, this is not supported by reported outcomes.

Conclusion

Absolute contraindications to a particular dialysis modality are rare. Relative indications for or against particular modalities should be considered but are rarely more important than patient preferences.

Systemic Immune-Inflammation Index Was Significantly Associated with All-Cause and Cardiovascular-Specific Mortalities in Patients Receiving Peritoneal Dialysis

Purpose

The prognosis of patients receiving peritoneal dialysis (PD) is associated with inflammation. Systemic immune-inflammation index (SII) is one of inflammatory markers, and the role in predicting clinical outcomes in PD patients is unclear. We aimed to investigate the relationship between the SII and all-cause and cardiovascular-specific mortalities in patients undergoing PD.

Patients and Methods

A total of 1419 PD patients from the First Affiliated Hospital of Sun Yat-sen University between January 1, 2007 and December 31, 2019 were retrospectively included at baseline, and the patients were followed up until November 31, 2021. SII was calculated as platelet count×neutrophil count/lymphocyte count. Kaplan-Meier curves and Cox proportional hazards regression models were used to determine the relationship between SII levels and all-cause and cardiovascular-specific mortalities.

Results

During follow-up (median period was 42 months), 321 patients died (171 died of cardiovascular disease). With adjustment for the potential confounding factors, each 1-SD increase in the SII was associated with 20.2% increase in all-cause mortality (hazard ratio [HR]: 1.202, 95% confidence interval [CI]: 1.088-1.327, P<0.001) and 28.0% increase in cardiovascular-specific mortality (HR: 1.280, 95% CI: 1.126-1.456, P<0.001). High SII (vs low SII) was significantly associated with increased risks of all-cause mortality (HR: 1.391, 95% CI: 1.066-1.815, P-value: 0.015) and cardiovascular-specific mortality (HR: 1.637, 95% CI: 1.185-2.261, P-value: 0.003). Subgroups analyses showed similar results for those younger than 65-year-old only.

Conclusion

Elevated SII level was independently associated with increased risks of all-cause and cardiovascular-specific mortalities in PD patients, especially for those younger than 65-year-old.

A Service Reconfiguration Bundle for Expanding Access to Peritoneal Dialysis Including for Older Frailer Patients

INTRODUCTION

Rates of peritoneal dialysis (PD) have been traditionally low in Northern Ireland. With rising numbers of patients reaching end-stage kidney disease, PD is a more cost-effective treatment than haemodialysis and aligns with international goals to increase home-based dialysis options. The aim of our study was to highlight how a service reconfiguration bundle expanded access to PD in Northern Ireland.

METHODS

The service reconfiguration bundle consisted of the appointment of a surgical lead, a dedicated interventional radiologist for fluoroscopically guided PD catheter insertion, and a nephrology-led ultrasound-guided PD catheter insertion service in an area of particular need. All patients in Northern Ireland who had a PD catheter inserted in the year following service reconfigurations were included and prospectively followed up for one-year. Patient demographics, PD catheter insertion technique, setting of procedure, and outcome data were summarised.

RESULTS

The number of patients receiving PD catheter insertion doubled to 66 in the year following service reconfigurations. The range of approaches to PD catheter insertion (laparoscopic n = 41, percutaneous n = 24 and open n = 1) allowed a wide range of patients to benefit from PD. Six patients had emergency PD catheter insertion, with four receiving urgent or early start PD. Nearly half (48%, 29/60) of the PD catheters inserted electively were in smaller elective hubs rather than the regional unit. A total of 97% of patients successfully started PD. Patients who experienced percutaneous PD catheter insertion were older [median age 76 (range 37-88) vs. 56 (range 18-84), p < 0.0001] and had less previous abdominal surgery than patients who experienced laparoscopic PD catheter insertion (25%, 6/24 vs. 54%, 22/41, p = 0.05).

DISCUSSION

Through a service reconfiguration bundle, we were able to double our annual incident PD population. This study highlights how flexible models of service delivery introduced as a bundle can quickly deliver expanded access to PD and home therapy.

Activation of AMPK-PGC-1α pathway ameliorates peritoneal dialysis related peritoneal fibrosis in mice by enhancing mitochondrial biogenesis

BACKGROUND

The pathogenesis of peritoneal dialysis (PD)-related peritoneal fibrosis (PF) is not clearly understood, and current treatment options are limited.

METHODS

In this study, the effect of PD-related PF on mitochondrial biogenesis was investigated, and the effect of activation of the adenosine monophosphate-activated protein kinase (AMPK)-PGC-1α (peroxisome proliferator-activated receptor γ coactivator-1α) pathway on PF was evaluated in mice.

RESULTS

In a mouse model of PD-related PF, AMPK-PGC-1α signaling (phospho-AMPK, PGC-1α, NRF-1, NRF-2 and TFAM expression) was downregulated, mitochondrial DNA (mtDNA) levels were reduced, and mitochondrial structure was damaged in the peritoneum. In addition, TdT-mediated dUTP nick-end labeling (TUNEL) staining showed typical apoptosis characteristics in peritoneal mesothelial cells (PMCs). Activation of the AMPK-PGC-1α pathway (PGC-1α overexpression or metformin, which is an agonist of AMPK) upregulated phospho-AMPK, PGC-1α, nuclear respiratory factors 1 (NRF-1) and 2 (NRF-2), and mitochondrial transcription factor A (TFAM) expression and mtDNA content, improved mitochondrial morphological manifestations, inhibited apoptosis of PMCs and alleviated PF.

CONCLUSION

Our study may suggest that activation of the AMPK-PGC-1α pathway ameliorates PD-related PF by enhancing mitochondrial biogenesis.

Evolving peritoneal dialysis care in Chinese mainland from 2010 to 2020: Comparison data from two surveys

INTRODUCTION

Along with the peritoneal dialysis (PD)-favored policy in China and the implementation of more comprehensive PD management, PD has evolved in Chinese mainland over the last decade. Despite the existence of national registries and several provincial epidemiological descriptive studies, there was almost no national research on the changing trajectory in PD population. A comparison study, based on two national surveys that were 10 years apart, was conducted to reveal the evolvement of PD care in Chinese mainland.

METHODS

Two national surveys have been done respectively in 2010 and 2020 to capture the epidemiological status, application of different modalities, management of perioperative infection, and long-term complications among PD patients.

RESULTS

In the study with 730 participating hospitals (n = 14,912 PD patients) in 2010 and 746 hospitals (n = 101,537) in 2020, prevalent PD patients have increased in the past 10 years with increased numbers of PD patients in both secondary (average 5 ± 16 vs. 43 ± 41, p < 0.01) and tertiary hospitals (32 ± 53 vs. 153 ± 215, p < 0.01). Automated PD has been accessible in 0.4% of all hospitals, only in tertiary centers in 2010 and its application increased to 51% in 2020. PD centers have become more engaged in PD catheter placement, treated properly for the PD-related infection, and carried out the follow-up in compliance with the national protocols.

CONCLUSIONS

Our study indicates that over the past decade, the prevalent PD population has quickly expanded with increased APD availability in Chinese mainland. The management of PD patients has become better conforming to the guidelines and long-term follow-up of patients have remained stable. Further studies are warranted to evaluate whether the rapidly changing paradigm of PD could translate into the socio-economic benefits in the society.

Development and Validation of a Prediction Model for the Cure of Peritoneal Dialysis-Associated Peritonitis: A Multicenter Observational Study

Aim

Peritoneal dialysis (PD)-associated peritonitis (PDAP) is a severe complication of PD. It is an important issue about whether it can be cured. At present, there is no available prediction model for peritonitis cure. Therefore, this study aimed to develop and validate a prediction model for peritonitis cure in patients with PDAP.

Methods

Patients with PD who developed PDAP from four dialysis centers in Northeast China were followed up. According to the region of PD, data were divided into training and validation datasets. Initially, a nomogram for peritonitis cure was established based on the training dataset. Later, the nomogram performance was assessed by discrimination (C-statistic), calibration, and decision curves.

Results

Totally, 1,011 episodes of peritonitis were included in the final analysis containing 765 in the training dataset and 246 in the validation dataset. During the follow-up period, peritonitis cure was reported in 615 cases from the training dataset and 198 from the validation dataset. Predictors incorporated in the final nomogram included PD duration, serum albumin, antibiotics prior to admission, white cell count in peritoneal dialysate on day 5 (/μl) ≥ 100/μl, and type of causative organisms. The C-statistic values were 0.756 (95% CI: 0.713–0.799) in the training dataset and 0.756 (95% CI: 0.681–0.831) in the validation dataset. The nomogram exhibited favorable performance in terms of calibration in both the training and validation datasets.

Conclusion

This study develops a practical and convenient nomogram for the prediction of peritonitis cure in patients with PDAP, which assists in clinical decision-making.

Influence of peritoneal dialysis catheter type on dislocations and laxative use: a retrospective observational study

Background

There is currently no consensus regarding the optimal type of peritoneal dialysis (PD) catheter. Although few studies showed that weighted catheters result in lower complication rates and superior long-term outcomes than non-weighted catheters, there are no studies on the use of laxatives linked to catheter malfunction, a patient-related outcome potentially affecting the quality of life. Thus, we compared the burden of acute and chronic laxative use in a cohort of PD patients having either weighted or non-weighted catheters.

Methods

We performed a single-center, retrospective, observational study in two renal units, comparing acute and chronic laxative therapy related to catheter drainage failure in a cohort of 74 PD patient,s divided by peritoneal dialysis catheter type. In addition, we evaluated the number of patients who experienced minor and major dislocations, catheter-related infection rate, hospitalization for catheter malfunctioning, episodes of catheter repositioning, and dropout from PD.

Results

Laxative use was significantly more common among patients in the non-weighted catheter group (acute: 30.3% vs. 9.8%, p = 0.03; chronic: 36.4% vs. 12.2%; p≤0.02). Furthermore, weighted catheters were superior to non-weighted catheters for all the secondary outcomes (dislocations: 12.2% vs. 45.5%; p = 0.001).

Conclusions

Weighted self-locating catheters have lower drainage failure, thus reducing the need and burden of acute and chronic laxative use among PD patients.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s40620-022-01329-6.

[Development and validation of a prediction model for treatment failure in peritoneal dialysis-associated peritonitis patients: a multicenter study]

OBJECTIVE

To develop and validate a risk prediction model of treatment failure in patients with peritoneal dialysis-associated peritonitis (PDAP).

METHODS

We retrospectively analyzed the data of patients undergoing peritoneal dialysis (PD) in 3 dialysis centers in Jilin Province who developed PDAP between January 1, 2013 and December 31, 2019. The data collected from the Second Hospital of Jilin University and Second Division of First Hospital of Jilin University) were used as the training dataset and those from Jilin Central Hospital as the validation dataset. We developed a nomogram for predicting treatment failure using a logistic regression model with backward elimination. The performance of the nomogram was assessed by analyzing the C-statistic and the calibration plots. We also plotted decision curves to evaluate the clinical efficacy of the nomogram.

RESULTS

A total of 977 episodes of PDAP were included in the analysis (625 episodes in the training dataset and 352 episodes in the validation dataset). During follow-up, 78 treatment failures occurred in the training dataset and 35 in the validation dataset. A multivariable logistic regression prediction model was established, and the predictors in the final nomogram model included serum albumin, peritoneal dialysate white cell count on day 5, PD duration, and type of causative organisms. The nomogram showed a good performance in predicting treatment failure, with a C-statistic of 0.827 (95% CI: 0.784-0.871) in the training dataset and of 0.825 (95% CI: 0.743-0.908) in the validation dataset. The nomogram also performed well in calibration in both the training and validation datasets.

CONCLUSION

The established nomogram has a good accuracy in estimating the risk of treatment failure in PDAP patients.

Low Serum Albumin Is Associated with Poor Prognosis in Patients Receiving Peritoneal Dialysis Treatment

Background

The number of patients receiving dialysis treatment is sustainably increasing, especially peritoneal dialysis.

Objectives

It is necessary to find out potential factors that may indicate the prognosis of patients receiving peritoneal dialysis treatment.

Methods

This study retrospectively involved 325 patients who received peritoneal dialysis treatment.

Results

Low serum albumin (HR = 2.254; 95% CI: 1.534-3.311; P < 0.001) and high FBG (Fasting blood glucose) (HR = 1.474; 95% CI: 1.025-2.120; P=0.037) were risk factors for death in patients receiving peritoneal dialysis treatment. Serum albumin (AUC = 0.683; P < 0.001) and creatinine (AUC = 0.625; P < 0.001) exhibited value of prognosis prediction. Both high FBG (P=0.005) and low albumin (P < 0.001) were associated with poor prognosis, and low albumin predicted poorer survival.

Conclusions

Low serum albumin and high fasting blood glucose were risk factors and associated with poor prognosis. Low albumin has a potential in predicting the prognosis of patients receiving peritoneal dialysis treatment.

Patient and Clinician Perspectives on the use of Remote Patient Monitoring in Peritoneal Dialysis

Background:

Numerous factors influence patient recruitment to, and retention on, peritoneal dialysis (PD), but a major challenge is a perceived “inaccessibility” to treating clinicians. It has been suggested that remote patient monitoring (RPM) could be a means of improving such oversight and, thereby, uptake of PD.

Objective:

To describe patient and clinician perspectives toward RPM and the use of applications (Apps) suitable for mobiles, tablets, or computers to support the provision of PD care.

Design:

Qualitative design using semi-structured interviews.

Setting:

All patient participants perform PD treatment at home under the oversight of an urban PD unit in Sydney, Australia. Patient and clinician interviews were conducted within the PD unit.

Participants:

14 participants (5 clinicians [2 nephrologists, 3 PD nurses] and 9 patients treated with PD).

Methods:

Semi-structured interviews were conducted using interview guides tailored for clinician and patient participants. Transcripts were coded and analyzed by a single researcher using thematic analysis.

Results:

Six themes were identified: perceived benefits of RPM implementation (offering convenience and efficiency, patient assurance through increased surveillance, more complete data and monitoring adherence), uncertainty regarding data governance (protection of personal data, data reliability), reduced patient engagement (transfer of responsibility leading to complacency), changing patient-clinician relationships (reduced patient-initiated communication, the need to maintain patient independence), increased patient and clinician burden (inadequate technological literacy, overmanagement leading to frequent treatment changes), and clinician preference influencing patient behavior.

Limitations:

The interviews were conducted in English only and with participants from a single urban dialysis unit, which may limit generalizability.

Conclusions:

For patients and clinicians, advantages from the use of RPM in PD may include increased patient confidence and assurance, improved treatment oversight, more complete data capture, and overcoming barriers to data documentation. Careful patient selection and patient and clinician education may help to optimize the benefits of RPM, maintain patient independence, and reduce the risks of patient disengagement. The use of an App may support RPM; however, participants expressed concerns about increasing the burden on some patients through the use of unfamiliar technology.

Human Research Ethics Committee Approval Number:

CH62/6/2019-028

Gut microbial metabolite TMAO increases peritoneal inflammation and peritonitis risk in peritoneal dialysis patients

Trimethylamine-N-oxide (TMAO), a gut microbiota-produced metabolite, is accumulated in chronic kidney disease (CKD) patients. It is well known to contribute to CKD-related cardiovascular complications. However, the effect of TMAO on peritoneal dialysis (PD)-related peritonitis remains largely unknown. Here, we demonstrate that serum concentrations of TMAO were positively correlated with C-reactive protein levels, and the appearance rate of dialysate IL-6 and PAI-1, in PD patients. During the follow-up period of 28.3 ± 8.0 months, patients with higher TMAO levels (≥50 μM) had a higher risk of new-onset peritonitis (HR, 3.60; 95%CI, 1.18-10.99; P=0.025) after adjusting for sex, age, diabetes, PD duration, BUN, rGFR, C-reactive protein, BMI and β2-M. In CKD rat models, TMAO significantly promoted peritoneal dialysate-induced inflammatory cell infiltration, inflammatory cytokines production in the peritoneum. In vitro study revealed that TMAO directly induced primary peritoneal mesothelial cell necrosis, together with increased production of pro-inflammatory cytokines including CCL2, TNF-α, IL-6, and IL-1β. In addition, TMAO significantly increased TNF-α-induced P-selectin production in mesothelial cells, as well as high glucose-induced TNF-α and CCL2 expression in endothelial cells. In conclusion, our data demonstrate that higher levels of TMAO exacerbate peritoneal inflammation and might be a risk factor of incidence of peritonitis in PD patients.

Choice of dialysis modality among patients initiating dialysis: results of the Peridialysis study

Background

In patients with end-stage kidney disease (ESKD), home dialysis offers socio-economic and health benefits compared with in-centre dialysis but is generally underutilized. We hypothesized that the pre-dialysis course and institutional factors affect the choice of dialysis modality after dialysis initiation (DI).

Methods

The Peridialysis study is a multinational, multicentre prospective observational study assessing the causes and timing of DI and consequences of suboptimal DI. Clinical and biochemical data, details of the pre-dialytic course, reasons for DI and causes of the choice of dialysis modality were registered.

Results

Among 1587 included patients, 516 (32.5%) were judged unsuitable for home dialysis due to contraindications [384 ( 24.2%)] or no assessment [106 (6.7%); mainly due to late referral and/or suboptimal DI] or death [26 (1.6%)]. Older age, comorbidity, late referral, suboptimal DI, acute illness and rapid loss of renal function associated with unsuitability. Of the remaining 1071 patients, 700 (65.4%) chose peritoneal dialysis (61.7%) or home haemodialysis (HD; 3.6%), while 371 (34.6%) chose in-centre HD. Somatic differences between patients choosing home dialysis and in-centre dialysis were minor; factors linked to the choice of in-centre dialysis were late referral, suboptimal DI, acute illness and absence of a ‘home dialysis first’ institutional policy.

Conclusions

Given a personal choice with shared decision making, 65.4% of ESKD patients choose home dialysis. Our data indicate that the incidence of home dialysis potentially could be further increased to reduce the incidence of late referral and unplanned DI and, in acutely ill patients, by implementing an educational programme after improvement of their clinical condition.

Management of Kidney Failure in Patients with Diabetes Mellitus: What Are the Best Options?

Diabetic kidney disease (DKD) is the most frequent cause of kidney failure (KF). There are large variations in the incidence rates of kidney replacement therapy (KRT). Late referral to nephrology services has been associated with an increased risk of adverse outcomes. In many countries, when patients reach severely reduced glomerular filtration rate (GFR), they are managed by multidisciplinary teams led by nephrologists. In these clinics, efforts will continue to halt chronic kidney disease (CKD) progression and to prevent cardiovascular mortality and morbidity. In patients with diabetes and severely reduced GFR and KF, treating hyperglycemia is a challenge, since some drugs are contraindicated and most of them require dose adjustments. Even more, a decision-making process will help in deciding whether the patient would prefer comprehensive conservative care or KRT. On many occasions, this decision will be conditioned by diabetes mellitus itself. Effective education should cover the necessary information for the patient and family to answer these questions: 1. Should I go for KRT or not? 2. If the answer is KRT, dialysis and/or transplantation? 3. Dialysis at home or in center? 4. If dialysis at home, peritoneal dialysis or home hemodialysis? 5. If transplantation is desired, discuss the options of whether the donation would be from a living or deceased donor. This review addresses the determinant factors with an impact on DKD, aiming to shed light on the specific needs that arise in the management and recommendations on how to achieve a comprehensive approach to the diabetic patient with chronic kidney disease.

Neutrophil to Lymphocyte Ratio as a Predictor of Long-Term Outcome in Peritoneal Dialysis Patients: A 5-Year Cohort Study

INTRODUCTION

The mortality of peritoneal dialysis (PD) patients remains high. The neutrophil to lymphocyte ratio (NLR), as an indicator of systemic inflammation, has been considered to be a predictor of cardiovascular and all-cause mortality in hemodialysis patients. The present study aims to investigate the relationship between NLR and long-term outcome in PD patients.

MATERIALS AND METHODS

The study included patients who initiated PD for at least 3 months between January 1, 2013, and December 31, 2015. All the patients were followed up until death, cessation of PD, or to the end of the study (June 31, 2018). NLR was calculated as the ratio of neutrophils to lymphocytes.

RESULTS

A total of 140 patients were included in this study. The median NLR reported was 2.87. Patients with lower NLR showed a higher survival rate than patients with higher NLR (log rank 6.886, p = 0.009). Furthermore, patients with higher NLR had a significantly higher cardiovascular mortality (log rank 5.221, p = 0.022). Multivariate Cox proportional hazards model showed that older age (HR 1.054, 95% CI 1.017-1.092, p = 0.004), higher Ca × P (HR 1.689, 95% CI 1.131-2.523, p = 0.010), and higher NLR (HR 2.603, 95% CI 1.037-6.535, p = 0.042) were independent predictors of increased all-cause mortality. NLR was also independently associated with cardiovascular mortality (HR 2.886, 95% CI 1.005-8.283, p = 0.039). Higher NLR (HR 2.667, 95% CI 1.333-5.337, p = 0.006), older age (HR 1.028, 95% CI 1.005-1.052, p = 0.016), and history of cardiovascular disease (HR 1.426, 95% CI 1.195-3.927, p = 0.031) were significantly independently associated with poor peritonitis-free survival in this study.

CONCLUSIONS

NLR could be a strong predictor of long-term outcome in PD patients.

Peritoneal Dialysis Fluid Supplementation with Alanyl-Glutamine Attenuates Conventional Dialysis Fluid-Mediated Endothelial Cell Injury by Restoring Perturbed Cytoprotective Responses

Long-term clinical outcome of peritoneal dialysis (PD) depends on adequate removal of small solutes and water. The peritoneal endothelium represents the key barrier and peritoneal transport dysfunction is associated with vascular changes. Alanyl-glutamine (AlaGln) has been shown to counteract PD-induced deteriorations but the effect on vascular changes has not yet been elucidated. Using multiplexed proteomic and bioinformatic analyses we investigated the molecular mechanisms of vascular pathology in-vitro (primary human umbilical vein endothelial cells, HUVEC) and ex-vivo (arterioles of patients undergoing PD) following exposure to PD-fluid. An overlap of 1813 proteins (40%) of over 3100 proteins was identified in both sample types. PD-fluid treatment significantly altered 378 in endothelial cells and 192 in arterioles. The HUVEC proteome resembles the arteriolar proteome with expected sample specific differences of mainly immune system processes only present in arterioles and extracellular region proteins primarily found in HUVEC. AlaGln-addition to PD-fluid revealed 359 differentially abundant proteins and restored the molecular process landscape altered by PD fluid. This study provides evidence on validity and inherent limitations of studying endothelial pathomechanisms in-vitro compared to vascular ex-vivo findings. AlaGln could reduce PD-associated vasculopathy by reducing endothelial cellular damage, restoring perturbed abundances of pathologically important proteins and enriching protective processes.

The Peritoneal Dialysis Telemedicine-assisted Platform Cohort (PDTAP) Study: Design and methods

OBJECTIVES

The primary objective of the Peritoneal Dialysis Telemedicine-assisted Platform Cohort (PDTAP) Study is to explore potential predictors and their effects on patient survival, technique survival, and the occurrence of infectious and noninfectious complications.

DESIGN

The PDTAP study is a national-level cohort study in China. A newly developed PD telemedicine application provided a unique and convenient way to collect multicenter, structured data across units.

SETTING

The PDTAP study was underway in 27 hospitals from 14 provinces located at 7 geographical regions (northwest, northeast, north, central, southwest, southeast, and south) in China.

PARTICIPANTS

Our study aims to enroll at least 7000 adult patients with end-stage renal disease receiving PD.

METHODS

Approval has been obtained through the ethics committees of all hospitals. All participants signed the informed consent form after the center had received ethics board approval in accordance with the Declaration of Helsinki.

MAIN OUTCOME MEASURES

Patient survival, technique survival, hospitalization, and the occurrence of infectious and noninfectious complications.

CONCLUSIONS

The PDTAP study aims to explore potential predictors and their effects on patient survival, technique survival, and infectious and noninfectious complications using a newly developed PD telemedicine system to collect multicenter, structured data in real-world practice. Substantial and transformable findings in relation to PD practices were expected. This study also developed a national-level infrastructure for further collaboration and ancillary investigation.

Predictors of technique failure and mortality on peritoneal dialysis: An analysis of New Zealand peritoneal dialysis registry data

AIM

Technique failure is a major disadvantage associated with peritoneal dialysis (PD). This study aimed to analyse the demographic and risk predictors of technique failure and mortality in patients on PD.

METHODS

All incidental PD patients registered on the New Zealand Peritoneal dialysis registry (NZPDR) from January 1995 to December 2014 were included in the study. The primary outcomes were time to technique failure and its specific causes, while as the secondary outcome was time to death. Risk predictors of technique failure and mortality were analysed using multivariate Cox proportional hazards (PH) regression model. Besides, competitive risk regression analysis was undertaken to analyse the effect of death as a competing event to technique failure.

RESULTS

Of 6379 patients, there were 2993 (46.9%) episodes of technique failure and 2684 (42%) deaths. The crude technique failure and mortality rates were 165 ± 5.90 and 147.9 ± 5.50 (mean ± SD)/1000 patient-years, respectively. Hazards of technique failure were lower in older individuals above 60 years, HR 0.72 (95% CI 0.67-0.79), larger centres, HR 0.89 (95% CI 0.79-1.00) and higher with coiled catheters, HR 1.26 (95% CI 1.16-1.37). Early nephrology referral, continuous ambulatory peritoneal dialysis (CAPD) and Asian ethnicities were associated with better technique survival. Infections were the major cause of technique failure (58.4%) with peritonitis being the leading cause (30.2%).

CONCLUSION

There are multiple factors associated with risk of technique failure, therefore it is persuasive to construct a mathematical model for early prediction, for a planned transition to HD.

Peritoneal dialysis patient selection from a comorbidity perspective

Despite many medical and socioeconomic advantages, peritoneal dialysis (PD) is an underutilized dialysis modality that in most countries is used by only 5%-20% of dialysis patients, while the vast majority are treated with in-center hemodialysis. Several factors may explain this paradox, such as lack of experience and infrastructure for training and monitoring of PD patients, organizational issues, overcapacity of hemodialysis facilities, and lack of economic incentives for dialysis centers to use PD instead of HD. In addition, medical conditions that are perceived (rightly or wrongly) as contraindications to PD represent barriers for the use of PD because of their purported potential negative impact on clinical outcomes in patients starting PD. While there are few absolute contraindications to PD, high age, comorbidities such as diabetes mellitus, obesity, polycystic kidney disease, heart failure, and previous history of abdominal surgery and renal allograft failure, may be seen (rightly or wrongly) as relative contraindications and thus barriers to initiation of PD. In this brief review, we discuss how the presence of these conditions may influence the strategy of selecting patients for PD, focusing on measures that can be taken to overcome potential problems.

Removal of Protein-Bound Uremic Toxins by Liposome-Supported Peritoneal Dialysis

Background:Protein-bound uremic toxins (PBUTs) are poorly cleared by peritoneal dialysis (PD). This study aimed to enhance PBUT removal in PD by adding a binder to the peritoneal dialysate and to evaluate the feasibility and efficacy of liposome-supported PD (LSPD) to increase the removal of PBUTs compared with albumin PD.Methods:Removal of p-cresyl sulfate (PCS), indoxyl sulfate (IS), and indole-3-acetic acid (3-IAA) was first evaluated in an in vitro PD model using artificial plasma preloaded with test solutes. Male Sprague-Dawley rats (n = 24) were then subjected to 5/6 nephrectomy and fed for 16 weeks to establish end-stage renal failure, after which they were treated with either conventional glucose-based PD, albumin-based PD, or liposome-based PD. Removal of PBUTs and small water-soluble solutes was determined during a 6-hour PD dwell.Results:In vitro experiments showed that adding albumin as a toxin binder to the dialysate markedly increased the removal of PCS, IS, and 3-IAA compared with the control. The uptake capacity of liposomes was comparable with that of albumin for PCS and 3-IAA, though slightly inferior for IS. In vivo PD in uremic rats demonstrated that LSPD resulted in higher intraperitoneal concentrations and more total mass removal for PBUTs than the conventional glucose-based PD, which was comparable with albumin PD.Conclusions:Supplementing conventional glucose-based PD solutions with a binder could efficiently increase the removal of PBUTs. This preliminary study suggested that LSPD may be a promising alternative to albumin PD for increasing PBUT removal in the development of next-generation PD solutions for PD patients.

Loosening of the mesothelial barrier as an early therapeutic target to preserve peritoneal function in peritoneal dialysis

Phenotype transition of peritoneal mesothelial cells (MCs) including the epithelial-to-mesenchymal transition (EMT) is regarded as an early mechanism of peritoneal dysfunction and fibrosis in peritoneal dialysis (PD), producing proinflammatory and pro-fibrotic milieu in the intra-peritoneal cavity. Loosening of intercellular tight adhesion between adjacent MCs as an initial process of EMT creates the environment where mesothelium and submesothelial tissue are more vulnerable to the composition of bio-incompatible dialysates, reactive oxygen species, and inflammatory cytokines. In addition, down-regulation of epithelial cell markers such as E-cadherin facilitates de novo acquisition of mesenchymal phenotypes in MCs and production of extracellular matrices. Major mechanisms underlying the EMT of MCs include induction of oxidative stress, pro-inflammatory cytokines, endoplasmic reticulum stress and activation of the local renin-angiotensin system. Another mechanism of peritoneal EMT is mitigation of intrinsic defense mechanisms such as the peritoneal antioxidant system and anti-fibrotic peptide production in the peritoneal cavity. In addition to use of less bio-incompatible dialysates and optimum treatment of peritonitis in PD, therapies to prevent or alleviate peritoneal EMT have demonstrated a favorable effect on peritoneal function and structure, suggesting that EMT can be an early interventional target to preserve peritoneal integrity.

Therapeutic effect of 1,25(OH)2-VitaminD3 on fibrosis and angiogenesis of peritoneum induced by chlorhexidine

The biological activity of vitamin D, which mediated by the vitamin D receptor, is widespread throughout the body. The present study aimed to define whether 1,25-dihydroxy vitamin D3 (1,25-(OH)2D3) can protect against the progression of peritoneum fibrosis (PF) through its impact on the expression of connective tissue growth factor (CTGF) and heat shock protein 47 (HSP47) in vivo and in vitro. The male Sprague-Dawley (SD) rats of PF were induced by daily intraperitoneally injection of chlorhexidine gluconate (CG) for 4 wks. PF Rats were also treated with calcitriol (i.p. 6 ng/100g*d) from initiation of the CG. In calcitriol rats, the ultrafiltration and the ratio of dialysate urea nitrogen to blood urea nitrogen were improved (P < 0.05), pathological changes and peritoneal thickness were milder than that of the PF group. Calcitriol ameliorated high glucose-induced HSP47 expression in peritoneal mesothelial cells via CTGF down-regulation both at the mRNA level and protein level. Furthermore, calcitriol prevented angiogenic mediators of fibrosis by reduced the expression of CD34 and vascular endothelial growth factor (VEGF). The present study demonstrated that 1,25-(OH)2D3 intervention had a partially protective effect on peritoneum fibrosis, which might inhibit CTGF/HSP47 and CD34/VEGF in the peritoneum tissues.

Effect of Liver Cirrhosis on the Outcomes of Peritoneal Dialysis

Background:Peritoneal dialysis (PD) has become an increasingly important treatment modality for end-stage renal disease. However, application of PD in patients with liver cirrhosis (LC) and subsequent outcomes have not been thoroughly evaluated.Methods:A total of 1,366 patients (≥ 18 years old) who started PD at 4 tertiary referral centers between January 2000 and December 2015 were initially reviewed. Among them, 45 patients with LC were finally analyzed (LC-PD). Using the multivariate Cox hazard ratio (HR) model, outcomes such as technique failure, infection, and mortality in patients with LC-PD were compared with those in non-LC-PD patients (non-LC-PD) or patients with LC who received hemodialysis (LC-HD). All of the patients were selected by 1:1 matching of age, sex, catheter insertion date, and diabetes mellitus.Results:During the mean follow-up duration of 43 ± 35.8 months, 12 patients with LC-PD experienced technique failure, and this rate was similar to that of non-LC-PD patients. In evaluating infection episodes, the most common causes for peritonitis and exit-site infection were Escherichia coli (5.8%) and Staphylococcus aureus (19.3%), respectively; these event rates of LC-PD did not differ from those of non-LC-PD. The all-cause mortality rate of the LC-PD group was not different from that of the non-LC-PD and LC-HD groups.Conclusion:Dialysis outcomes such as technique failure, infection, and mortality are not affected by the presence of LC. Accordingly, PD therapy is a good option in patients with LC.

Transcriptome analysis of signaling pathways of human peritoneal mesothelial cells in response to different osmotic agents in a peritoneal dialysis solution

Background

Glucose is a primary osmotic agent in peritoneal dialysis (PD) solutions, but its long-term use causes structural alteration of the peritoneal membrane (PM). Hyperbranched polyglycerol (HPG) is a promising alternative to glucose. This study was designed to compare the cellular responses of human peritoneal mesothelial cells (HPMCs) to these two different osmotic agents in a hypertonic solution using transcriptome analysis.

Methods

Cultured HPMCs were repeatedly exposed to HPG-based or Physioneal 40 (PYS, glucose 2.27%) hypertonic solutions. Transcriptome datasets were produced using Agilent SurePrint G3 Human GE 8 × 60 microarray. Cellular signaling pathways were examined by Ingenuity Pathway Analysis (IPA). Protein expression was examined by flow cytometry analysis and Western blotting.

Results

The HPG-containing solution was better tolerated compared with PYS, with less cell death and disruption of cell transcriptome. The levels of cell death in HPG- or PYS- exposed cells were positively correlated with the number of affected transcripts (HPG: 128 at day 3, 0 at day 7; PYS: 1799 at day 3, 212 at day 7). In addition to more affected “biosynthesis” and “cellular stress and death” pathways by PYS, both HPG and PYS commonly affected “sulfate biosynthesis”, “unfolded protein response”, “apoptosis signaling” and “NRF2-mediated oxidative stress response” pathways at day 3. PYS significantly up-regulated HLA-DMB and MMP12 in a time-dependent manner, and stimulated T cell adhesion to HPMCs.

Conclusion

The lower cytotoxicity of hypertonic HPG solution is in agreement with its transient and minimal impact on the pathways for the “biosynthesis of cell constituents” and the “cellular stress and death”. The significant up-regulation of HLA-DMB and MMP12 by PYS may be part of its initiation of immune response in the PM.

The Peritoneal Surface Proteome in a Model of Chronic Peritoneal Dialysis Reveals Mechanisms of Membrane Damage and Preservation

Peritoneal dialysis (PD) fluids are cytotoxic to the peritoneum. Recent studies have shown that alanyl-glutamine (AlaGln) modulates the cellular stress response, improves mesothelial cell survival, reduces submesothelial thickening in experimental models of PD, and in clinical studies improves PD effluent cell stress and immune responses. However, the mechanisms of AlaGln-mediated membrane protection are not yet fully understood. Here, we explore those mechanisms through application of a novel proteomics approach in a clinically relevant in vivo model in rats. Experimental PD was performed for 5 weeks using conventional single-chamber bag (SCB) or neutral dual-chamber bag (DCB), PD fluid (PDF), with or without AlaGln supplementation, via a surgically implanted catheter. Rats subjected to a single dwell without catheter implantation served as controls. The peritoneal surface proteome was directly harvested by detergent extraction and subjected to proteomic analysis by two-dimensional difference gel electrophoresis (2D-DiGE) with protein identification by mass spectrometry. An integrated bioinformatic approach was applied to identify proteins significantly affected by the treatments despite biological variation and interfering high abundance proteins. From 505 of 744 common spots on 59 gels, 222 unique proteins were identified. Using UniProt database information, proteins were assigned either as high abundance plasma proteins, or as cellular proteins. Statistical analysis employed an adapted workflow from RNA-sequencing, the trimmed mean of M-values (TMM) for normalization, and a mixed model for computational identification of significantly differentially abundant proteins. The most prominently enriched pathways after 5 weeks chronic treatment with SCB or DCB, PDFs belonged to clusters reflecting tissue damage and cell differentiation by cytoskeletal reorganization, immune responses, altered metabolism, and oxidative stress and redox homeostasis. Although the AlaGln effect was not as prominent, associated enriched pathways showed mostly regression to control or patterns opposite that of the PDF effect. Our study describes the novel peritoneal surface proteome through combined proteomic and bioinformatic analyses, and assesses changes elicited by chronic experimental PD. The biological processes so identified promise to link molecular mechanisms of membrane damage and protection in the in vivo rat model to pathomechanisms and cytoprotective effects observed in vitro and in clinical PD.

Dialysis Reimbursement: What Impact Do Different Models Have on Clinical Choices?

Allowing patients to live for decades without the function of a vital organ is a medical miracle, but one that is not without cost both in terms of morbidity and quality of life and in economic terms. Renal replacement therapy (RRT) consumes between 2% and 5% of the overall health care expenditure in countries where dialysis is available without restrictions. While transplantation is the preferred treatment in patients without contraindications, old age and comorbidity limit its indications, and low organ availability may result in long waiting times. As a consequence, 30–70% of the patients depend on dialysis, which remains the main determinant of the cost of RRT. Costs of dialysis are differently defined, and its reimbursement follows different rules. There are three main ways of establishing dialysis reimbursement. The first involves dividing dialysis into a series of elements and reimbursing each one separately (dialysis itself, medications, drugs, transportation, hospitalisation, etc.). The second, known as the capitation system, consists of merging these elements in a per capita reimbursement, while the third, usually called the bundle system, entails identifying a core of procedures intrinsically linked to treatment (e.g., dialysis sessions, tests, intradialyitc drugs). Each one has advantages and drawbacks, and impacts differently on the organization and delivery of care: payment per session may favour fragmentation and make a global appraisal difficult; a correct capitation system needs a careful correction for comorbidity, and may exacerbate competition between public and private settings, the latter aiming at selecting the least complex cases; a bundle system, in which the main elements linked to the dialysis sessions are considered together, may be a good compromise but risks penalising complex patients, and requires a rapid adaptation to treatment changes. Retarding dialysis is a clinical and economical goal, but the incentives for predialysis care are not established and its development may be unfavourable for the provider. A closer cooperation between policymakers, economists and nephrologists is needed to ensure a high quality of dialysis care.

Survival and Kidney Transplant Incidence on Home versus In-Center Hemodialysis, following Peritoneal Dialysis Technique Failure

Background

Peritoneal dialysis (PD) technique failure is often accompanied by complications that increase risks of hospitalization and death. Planned transition to hemodialysis may improve outcomes. Transitioning patients from PD to home hemodialysis (HHD) may improve continuity of lifestyle and facilitate delivery of more frequent treatment.

Methods

We analyzed United States Renal Data System (USRDS) data to compare the incidence of death and kidney transplant in patients who transferred from PD to HHD and matched patients who transferred from PD to in-center HD (IHD). We used Fine-Gray regression to estimate hazard ratios (HRs) of death and transplant for HHD versus IHD.

Results

We identified 521 patients who transferred from PD to HHD. Survival in HHD patients was 89.1% at 1 year and 80.5% at 2 years. In intention-to-treat analysis, the HR of death for HHD versus matched IHD patients was 0.76 (95% confidence interval [CI] 0.65 – 0.90). In subsets of non-Medicare and Medicare patients, corresponding HRs were 0.57 (95% CI 0.43 – 0.75) and 0.92 (95% CI 0.75 – 1.13), respectively. Kidney transplant incidence in HHD patients was 10.6% at 1 year and 21.0% at 2 years. In modified intention-to-treat analysis, the HR of transplant for HHD versus matched IHD patients was 1.36 (1.14 – 1.61).

Conclusions

Transfer to HHD after PD technique failure was rare, but associated with lower risk of death and higher incidence of transplant than transfer to IHD. Heterogeneity in relative risks by Medicare coverage suggests uncertainty about the magnitude of benefit. Still, these data suggest that clinical outcomes after PD technique failure can be improved.

PD First Policy: Thailand's Response to the Challenge of Meeting the Needs of Patients With End-Stage Renal Disease

Providing dialysis for end-stage kidney disease (ESKD) patients nationwide in a developing country such as Thailand is challenging. Even after roll-out of the Thai Universal Coverage Scheme in 2002, treatment for ESKD was not covered and patients struggled to afford dialysis. There was an urgent need to improve financial risk protection for patients with ESKD. Advocacy by nephrologists, health economists, and civil society seeking equity in access to dialysis, and responsiveness from policy makers, led to the methodical development of the Peritoneal Dialysis (PD) First policy and marked a turning point in ESKD care in Thailand. Despite the obvious economic concerns and the prevailing popularity of hemodialysis the policy has been strategically and successfully implemented since 2008. The Thai PD First policy has saved the lives of nearly 50,000 ESKD patients being dialyzed under the universal coverage scheme. Despite ongoing challenges the program continues to evolve. This article summarizes the key strategies underlying the policy development and implementation, the integration of home-based dialysis into the well-established Thai health care system, the use of the Chronic Care Model concept in PD care, and the impact of choosing PD as the first choice of dialysis therapy, which has slowed the growth of dialysis costs.

Apoptosis inhibitor of macrophage ameliorates fungus-induced peritoneal injury model in mice

Fungal peritonitis in a patient on peritoneal dialysis (PD) is a refractory injury accompanied by severe inflammation, predisposing patients to a poor prognosis. Defective clearance of necrotic tissue interferes with amelioration of tissue injury and induces abnormal tissue remodeling. In the recent reports, apoptosis inhibitor of macrophage (AIM, also called CD5L) prevents obesity, hepatocellular carcinoma and acute kidney injury. Here, we investigated potential roles of AIM in prevention of progression of fungal peritonitis models. AIM^−/− mice subjected to zymosan-induced peritonitis exhibited progressive inflammation and sustained peritoneal necrosis tissue on day 28 after the disease induction, whereas there was an improvement in AIM^+/+ mice. This appeared to be caused by deposition of AIM at the necrotic peritoneum in AIM^+/+ mice. In vitro, AIM enhanced the engulfment of necrotic debris by macrophages derived from zymosan-induced peritonitis, M1- and M2a-like bone marrow derived macrophages, as well as by mesothelial cells. In addition, administration of recombinant AIM dramatically ameliorated severe inflammation associated with necrosis in zymosan-induced peritonitis of AIM^−/− mice. Our observations suggest that AIM appears to be involved in the repair process of zymosan-induced peritonitis, and thus, could be the basis of development of new therapeutic strategies for PD-related fungal peritonitis.

Angiogenesis and Inflammation in Peritoneal Dialysis: The Role of Adipocytes

Chronic inflammation and angiogenesis are the most common complications in patients undergoing maintenance peritoneal dialysis (PD), resulting in progressive peritoneum remolding and, eventually, utrafiltration failure. Contributing to the deeper tissue under the peritoneal membrane, adipocytes play a neglected role in this process. Some adipokines act as inflammatory and angiogenic promoters, while others have the opposite effects. Adipokines, together with inflammatory factors and other cytokines, modulate inflammation and neovascularization in a coordinated fashion. This review will also emphasize cellular regulators and their crosstalk in long-term PD. Understanding the molecular mechanism, targeting changes in adipocytes and regulating adipokine secretion will help extend therapeutic methods for preventing inflammation and angiogenesis in PD.

Peritoneal dialysis practice in Australia and New Zealand: A call to sustain the action

This paper updates a previous 'Call to Action' paper (Nephrology 2011; 16: 19-29) that reviewed key outcome data for Australian and New Zealand peritoneal dialysis patients and made recommendations to improve care. Since its publication, peritonitis rates have improved significantly, although they have plateaued more recently. Peritoneal dialysis patient and technique survival in Australian and New Zealand have also improved, with a reduction in the proportion of technique failures attributed to 'social reasons'. Despite these improvements, technique survival rates overall remain lower than in many other parts of the world. This update includes additional practical recommendations based on published evidence and emerging initiatives to further improve outcomes.

Cost-effectiveness of hemodialysis and peritoneal dialysis: A national cohort study with 14 years follow-up and matched for comorbidities and propensity score

Although treatment for the dialysis population is resource intensive, a cost-effectiveness analysis comparing hemodialysis (HD) and peritoneal dialysis (PD) by matched pairs is still lacking. After matching for clinical characteristics and propensity scores, we identified 4,285 pairs of incident HD and PD patients from a Taiwanese national cohort during 1998-2010. Survival and healthcare expenditure were calculated by data of 14-year follow-up and subsequently extrapolated to lifetime estimates under the assumption of constant excess hazard. We performed a cross-sectional EQ-5D survey on 179 matched pairs of prevalent HD and PD patients of varying dialysis vintages from 12 dialysis units. The product of survival probability and the mean utility value at each time point (dialysis vintage) were summed up throughout lifetime to obtain the quality-adjusted life expectancy (QALE). The results revealed the estimated life expectancy between HD and PD were nearly equal (19.11 versus 19.08 years). The QALE's were also similar, whereas average lifetime healthcare costs were higher in HD than PD (237,795 versus 204,442 USD) and the cost-effectiveness ratios for PD and HD were 13,681 and 16,643 USD per quality-adjusted life year, respectively. In conclusion, PD is more cost-effective than HD, of which the major determinants were the costs for the dialysis modality and its associated complications.

How to meet the demand for good quality renal dialysis as part of universal health coverage in resource-limited settings?

BACKGROUND

It is very challenging for resource-limited settings to introduce universal health coverage (UHC), particularly regarding the inclusion of high-cost renal dialysis as part of the UHC benefit package. This paper addresses three issues: (1) whether a setting commits to include renal dialysis in its UHC benefit package and if so, why and how; (2) how to ensure quality of renal dialysis services; and (3) how to improve the quality of life of patients using psychosocial and community interventions.

DISCUSSION

This article reviews experiences of renal dialysis programs in seven settings based on presentations and discussions during the International Forum on Peritoneal Dialysis as a Priority Health Policy in Asia. A literature review was conducted to verify and validate the data as well as to fill information gaps presented in the forum. Five out of the seven settings implemented renal dialysis as part of their benefits package, while the other two have pilots or programs in their nascent stage. Renal replacement therapy has become part of the universal access package because these governments recognize the rising number of chronic kidney disease (CKD) cases, the catastrophically high costs of treatment, and that this is the only life-saving treatment available to patients. The recommendations are as follows: Governments should have a holistic approach to CKD interventions, including primary prevention as well as psychosocial interventions. Governments should consider subsidizing CKD treatment costs depending on their resources. Multi-stakeholder cooperation should be facilitated to enact these policies and conduct research and development for all aspects of interventions. International collaboration should be initiated to share experiences, good practices, and joint activities (e.g. capacity building and multinational procurement of medical supplies).

CONCLUSION

This study provides practical recommendations to country governments as well as the international community on how to meet the demand for good quality renal dialysis as part of UHC in resource-limited settings.

Transition of mesothelial cell to fibroblast in peritoneal dialysis: EMT, stem cell or bystander?

Long-term peritoneal dialysis (PD) can lead to fibrotic changes in the peritoneum, characterized by loss of mesothelial cells (MCs) and thickening of the submesothelial area with an accumulation of collagen and myofibroblasts. The origin of myofibroblasts is a central question in peritoneal fibrosis that remains unanswered at present. Numerous clinical and experimental studies have suggested that MCs, through epithelial-mesenchymal transition (EMT), contribute to the pool of peritoneal myofibroblasts. However, recent work has placed significant doubts on the paradigm of EMT in organ fibrogenesis (in the kidney particularly), highlighting the need to reconsider the role of EMT in the generation of myofibroblasts in peritoneal fibrosis. In particular, selective cell isolation and lineage-tracing experiments have suggested the existence of progenitor cells in the peritoneum, which are able to switch to fibroblast-like cells when stimulated by the local environment. These findings highlight the plastic nature of MCs and its contribution to peritoneal fibrogenesis. In this review, we summarize the key findings and caveats of EMT in organ fibrogenesis, with a focus on PD-related peritoneal fibrosis, and discuss the potential of peritoneal MCs as a source of myofibroblasts.

Impact of initial dialysis modality on mortality: a propensity-matched study

BACKGROUND

Whether the choice of dialysis modality in patients with end stage renal disease may impact mortality is undecided. No randomized controlled trial has properly addressed this issue. Propensity-matched observational studies could give important insight into the independent effect of peritoneal (PD) opposed to haemodialysis (HD) on all-cause and cardiovascular mortality.

METHODS

To correct for case-mix differences between patients treated with PD and HD, propensity-matched analyses were utilized in all patients who initiated dialysis as first renal replacement therapy in Norway in the period 2005-2012. PD patients were matched in a 1:1 fashion with HD patients, creating 692 pairs of patients with comparable baseline variables. As-treated and intention-to treat analyses were undertaken to assess cardiovascular and all-cause mortality. Interaction analyses were used to assess differences in the relationship between initial dialysis modality and mortality, between strata of age, gender and prevalent diabetes mellitus.

RESULTS

In the as-treated analyses, initial dialysis modality did not impact 2-year (PD vs. HD: HR 0.87, 95 % CI 0.67-1.12) or 5-year all-cause mortality (HR 0.95, 95 % CI 0.77-1.17). In patients younger than 65 years, PD was superior compared to HD with regard to both 2-year (HR 0.39, 95 % CI 0.19-0.81), and 5-year all-cause mortality (HR 0.49, 95 % CI 0.27-0.89). Cardiovascular mortality was also lower in the younger patients treated with PD (5-year HR 0.38, 95 % CI 0.15-0.96). PD was not associated with impaired prognosis in any of the prespecified subgroups compared to HD. The results were similar in the as-treated and intention-to-treat analyses.

CONCLUSION

Survival in PD was not inferior to HD in any subgroup of patients even after five years of follow-up. In patients below 65 years, PD yielded superior survival rates compared to HD. Increased use of PD as initial dialysis modality in ESRD patients could be encouraged.

Peritoneal Dialysis in Asia

BACKGROUND

There is a growing demand of dialysis in Asia for end-stage renal failure patients. Diabetes mellitus is the leading cause of end-stage renal failure in many countries in Asia.

SUMMARY

The growth of peritoneal dialysis (PD) in Asia is significant and seeing a good trend. With the enhanced practices of PD, the quality of care in PD in Asia is also improved. Overall, PD and hemodialysis (HD) are comparable in clinical outcome. There is a global trend in the reduction of peritonitis rates and Asian countries also witness such improvement. The socio-economic benefits of PD for end-stage renal failure patients in both urban and rural areas in the developed and developing regions of Asia are an important consideration. This can help to reduce the financial burden of renal failure in addressing the growing demand of patients on dialysis. Initiatives should be considered to further drive down the cost of PD in Asia.

KEY MESSAGES

Growing demand for dialysis by an increasing number of end-stage renal failure patients requires the use of a cost-effective quality dialysis modality. PD is found to be comparable to HD in outcome and quality. In most countries in Asia, PD should be more cost-effective than HD. A 'PD-first' or a 'PD as first considered therapy' policy can be an overall strategy in many countries in Asia in managing renal failure patients, taking the examples of Hong Kong and Thailand.

FACTS FROM EAST AND WEST

(1) PD is cheaper than HD and provides a better quality of life worldwide, but its prevalence is significantly lower than that of HD in all countries, with the exception of Hong Kong. Allowing reimbursement of PD but not HD has permitted to increase the use of PD over HD in many Asian countries like Hong Kong, Vietnam, Taiwan, Thailand, as well as in New Zealand and Australia over the last years. In the Western world, however, HD is still promoted, and the proportion of patients treated with PD decreases. Japan remains an exception in Asia where PD penetration is very low. Lack of adequate education of practitioners and information of patients might as well be reasons for the low penetration of PD in both the East and West. (2) Patient survival of PD varies between and within countries but is globally similar to HD. (3) Peritonitis remains the main cause of morbidity in PD patients. South Asian countries face specific issues such as high tuberculosis and mycobacterial infections, which are rare in developed Asian and Western countries. The infection rate is affected by climatic and socio-economic factors and is higher in hot, humid and rural areas. (4) Nevertheless, the promotion of a PD-first policy might be beneficial particularly for remote populations in emerging countries where the end-stage renal disease rate is increasing dramatically.

Morphological Retrospective Study of Peritoneal Biopsies from Patients with Encapsulating Peritoneal Sclerosis: Underestimated Role of Adipocytes as New Fibroblasts Lineage?

Background. Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication of peritoneal dialysis (PD). Besides the endothelial-to-mesenchymal transition (EMT), recently peritoneal adipocytes emerged as a potential source of fibrosis. We performed immunohistochemistry to approach EMT and to localize peritoneal adipocytes in peritoneal biopsies from PD-related EPS patients. Material and Methods. We investigated tissue expression of podoplanin, cytokeratin AE1/AE3 (mesothelium), calretinin (adipocytes), alpha-smooth muscle actin [α-SMA] (mesenchymal cells), interstitial mononuclear cell inflammation, and neoangiogenesis (CD3, CD4, CD8, CD20, CD68, and CD31 immunostainings, resp.). Results. Three patients (1 man/2 women; 17, 64, and 39 years old, resp.) developed EPS after 21, 90, and 164 months of PD therapy. In patients with EPS, we observed (1) loss of AE1/AE3 cytokeratin+ mesothelial cells without any evidence of migration into the interstitium, (2) disappearance of adipose tissue, (3) diffuse infiltration of calretinin+ cells in the areas of submesothelial fibrosis with a huge number of α-SMA and calretinin+ fusiform cells, and (4) increased vascular density. Conclusion. We report that the involvement of EMT in peritoneal fibrosis is difficult to demonstrate and that the calretinin+ adipocytes might be an underestimated component and a new source of myofibroblasts in peritoneal remodeling during PD-related EPS.

Hemodialysis Is Associated With Increased Peripheral Artery Occlusive Disease Risk Among Patients With End-Stage Renal Disease: A Nationwide Population-Based Cohort Study

To investigate the effect of different dialysis modalities on the incidence of peripheral artery occlusive disease (PAOD) among patients with end-stage renal disease (ESRD) in a large population-based cohort study. The cohort study included 26,927 ESRD patients who underwent hemodialysis (17,737 patients, hemodialysis [HD] cohort) or peritoneal dialysis (PD, 9190 patients, PD cohort), and 107,588 matched controls between 2000 and 2010. A Cox proportional hazards model was to evaluate the risk of PAOD in the ESRD underwent HD or PD. Based on a mean follow-up period of 2.92, 3.64, and 4.91 years in the PD, HD, and control cohorts, respectively, the incidences of PAOD were 18.1% and 8.10% higher in the HD and PD cohorts, respectively, compared with the control cohort (log-rank test P < 0.001). The patients who underwent HD or PD exhibited a higher risk of PAOD compared with the control cohort regardless of age, sex, and presence or absence of comorbidities. In addition, the incidence of PAOD in the PD cohort and the propensity score-matched HD cohort were 12.4 and 20.7 per 1000 person-years, respectively, with a hazard ratio of 1.92 (95% confidence interval = 1.62-2.28) in HD patients, compared with the PD cohort. This nationwide population-based cohort study suggested a significantly increased risk of PAOD among ESRD patients. Moreover, the PD patients have a lower risk of developing PAOD compared with the HD cohort, indicating the beneficial roles of PD in reducing PAOD risk in ESRD patients.