Novel Application of Magnetite Nanoparticle-Mediated Vitamin D3 Delivery for Peritoneal Dialysis-Related Peritoneal Damage

PURPOSE

Vitamin D3 is useful for the treatment of peritoneal dialysis (PD)-related peritoneal damage, but its side effects, such as hypercalcemia and vascular calcification, limit its applicability. Thus, we developed vitamin D-loaded magnetic nanoparticles (MNPs) and determined their therapeutic efficacy and side effects in vivo.

MATERIALS AND METHODS

Alginate-modified MNPs were combined with 1α, 25 (OH)2D3 to generate vitamin D-loaded nanoparticles. The particles were conjugated with an antibody against peritoneum-glycoprotein M6A (GPM6A). The particles' ability to target the peritoneum was examined following intraperitoneal administration to mice and by monitoring their bio-distribution. We also established a PD animal model to determine the therapeutic and side effects of vitamin D-loaded MNPs in vivo.

RESULTS

Vitamin D-loaded MNPs targeted the peritoneum better than vitamin D3, and had the same therapeutic effect as vitamin D3 in ameliorating peritoneal fibrosis and functional deterioration in a PD animal model. Most importantly, the particles reduced the side effects of vitamin D3, such as hypercalcemia and body weight loss, in mice.

CONCLUSION

Vitamin D-loaded MNPs could be an ideal future therapeutic option to treat PD-related peritoneal damage.

Risk factors for peritoneal dialysis withdrawal due to peritoneal dialysis-related peritonitis

BACKGROUND

Peritoneal dialysis has become commonly used for renal replacement therapy; however, some patients withdraw from peritoneal dialysis due to complications, including peritoneal dialysis-related peritonitis, resulting in the low number of patients on peritoneal dialysis. Risk factors for peritoneal dialysis withdrawal due to peritoneal dialysis-related peritonitis are less certain. This retrospective study aimed to investigate these risk factors.

METHODS

We retrospectively analyzed clinical characteristics, laboratory data, and causative microorganisms of 204 episodes of peritoneal dialysis-related peritonitis between 2007 and 2018 at our institution.

RESULTS

Of the 204 episodes, 38 resulted in withdrawal from peritoneal dialysis due to peritoneal dialysis-related peritonitis. The number of peritonitis episodes per patient-year and the incidence of cardiovascular disease were significantly higher in the withdrawal group. Similarly, this group had low levels of serum creatinine, urea nitrogen, serum albumin, alanine aminotransferase, cholinesterase and high C-reactive protein, and second dialysate cell counts after antibiotic administration. Multivariate logistic regression analysis revealed that serum albumin (odds ratio: 0.465; 95% confidence interval: 0.249-0.868; P=0.016) and cardiovascular disease (odds ratio: 2.508; 95% confidence interval: 1.184-5.315; P=0.016) exhibited significant differences.

CONCLUSIONS

The results of this study suggest that hypoalbuminemia and the presence of cardiovascular disease were independent risk factors for withdrawal from peritoneal dialysis due to peritoneal dialysis-related peritonitis.

Peritoneal Dialysis Utilization and Outcome: What are we Facing?

Penetration of peritoneal dialysis (PD) varies tremendously across the world. It ranges from about 80% in Hong Kong and Mexico to just a few percentage points in the United States, Japan, and Germany. While PD is growing in China, India, and some Eastern European and South American countries, it is declining in many European and North American countries. In terms of outcomes, the survival of PD patients is generally comparable to that of hemodialysis (HD) patients and better than that of HD patients during the first few years on dialysis. According to the U.S. Renal Data System, survival of patients on PD has been improving faster than that of patients on HD. In terms of cost, PD is usually cheaper than HD. Hence, declining PD utilization is unjustified. Work is required to identify and overcome negative factors such as physician bias, unfair medical reimbursement systems, and poor patient education.

Remote Treatment Monitoring on Hospitalization and Technique Failure Rates in Peritoneal Dialysis Patients

BACKGROUND

An integrated kidney disease healthcare company implemented a peritoneal dialysis (PD) remote treatment monitoring (RTM) application in 2016. We assessed if RTM utilization associates with hospitalization and technique failure rates.

METHODS

We used data from adult (age ≥18 years) patients on PD treated from October 2016 through May 2019 who registered online for the RTM. Patients were classified by RTM use during a 30-day baseline after registration. Groups were: nonusers (never entered data), moderate users (entered one to 15 treatments), and frequent users (entered >15 treatments). We compared hospital admission/day and sustained technique failure (required >6 consecutive weeks of hemodialysis) rates over 3, 6, 9, and 12 months of follow-up using Poisson and Cox models adjusted for patient/clinical characteristics.

RESULTS

Among 6343 patients, 65% were nonusers, 11% were moderate users, and 25% were frequent users. Incidence rate of hospital admission was 22% (incidence rate ratio [IRR]=0.78; P=0.002), 24% (IRR=0.76; P<0.001), 23% (IRR=0.77; P≤0.001), and 26% (IRR=0.74; P≤0.001) lower in frequent users after 3, 6, 9, and 12 months, respectively, versus nonusers. Incidence rate of hospital days was 38% (IRR=0.62; P=0.013), 35% (IRR=0.65; P=0.001), 34% (IRR=0.66; P≤0.001), and 32% (IRR=0.68; P<0.001) lower in frequent users after 3, 6, 9, and 12 months, respectively, versus nonusers. Sustained technique failure risk at 3, 6, 9, and 12 months was 33% (hazard ratio [HR]=0.67; P=0.020), 31% (HR=0.69; P=0.003), 31% (HR=0.69; P=0.001), and 27% (HR=0.73; P=0.001) lower, respectively, in frequent users versus nonusers. Among a subgroup of survivors of the 12-month follow-up, sustained technique failure risk was 26% (HR=0.74; P=0.023) and 21% (HR=0.79; P=0.054) lower after 9 and 12 months, respectively, in frequent users versus nonusers.

CONCLUSIONS

Our findings suggest frequent use of an RTM application associates with less hospital admissions, shorter hospital length of stay, and lower technique failure rates. Adoption of RTM applications may have the potential to improve timely identification/intervention of complications.

The Clinical Usefulness of Peritoneal Dialysis Fluids with Neutral pH and Low Glucose Degradation Product Concentration: An Open Randomized Prospective Trial

Background

Long-term peritoneal dialysis (PD) is associated with the development of various structural and functional changes to the peritoneal membrane when bioincompatible conventional peritoneal dialysis fluids (PDFs) are used. In this study, we looked at patients that were treated with conventional PDFs and then changed to novel biocompatible PDFs with a neutral pH and a low concentration of glucose degradation products (GDPs) to investigate whether this change could result in the arrest or reversal of peritoneal membrane deterioration.

Methods

In an open label, randomized prospective trial, the clinical effects of conventional PDFs and biocompatible PDFs with neutral pH and very low concentration of GDPs were compared in 104 patients equally divided between both study PDFs. Blood and effluent dialysate samples, peritoneal equilibration tests, and adequacy evaluation were undertaken at baseline, 4, 8, and 12 months. The target variables were the ratio of dialysate-to-plasma (D/P) creatinine, peritoneal ultrafiltration, residual renal function, dialysis adequacy indices, and effluent cancer antigen 125 (CA125).

Results

D/P creatinine values were not different in the two groups. Peritoneal ultrafiltration was significantly higher in the low-GDP PDF group than in the conventional PDF group at all follow-up times (4 months: 9.1 ± 4.3 vs 6.0 ± 3.0; 8 months: 8.3 ± 3.4 vs 6.0 ± 3.0; 12 months: 8.9 ± 3.3 vs 6.1 ± 3.3 mL/g dextrose/day; p < 0.05). Peritoneal Kt/V urea values and total weekly Kt/V urea values at 4 months were significantly higher in the low-GDP PDF group than in the conventional PDF group. Residual renal function was not statistically significant. Effluent CA125 levels were significantly higher in the low-GDP PDF group at all follow-up visits (4 months: 37.8 ± 20.8 vs 22.0 ± 9.5; 8 months: 41.2 ± 20.3 vs 25.9 ± 11.3; 12 months: 40.4 ± 21.4 vs 28.6 ± 13.0 U/mL; p < 0.05). Among anuric patients, peritoneal ultrafiltration at 4, 8, and 12 months, total weekly Kt/V at 4 and 8 months, and CA125 levels at all follow-up visits were significantly higher in patients treated with low-GDP PDF than those treated with conventional PDF. However, among anuric patients, D/P creatinine showed no significant differences between the low-GDP PDF group and the conventional PDF group.

Conclusion

The use of biocompatible PDFs with neutral pH and low GDP concentration can contribute to improvement of peritoneal ultrafiltration and peritoneal effluent CA125 level, an indicator of peritoneal membrane integrity in PD patients.

Overview of Peritoneal Dialysis in Latin America

Latin America is a heterogeneous region comprised of 20 countries, former colonies of European countries, in which Latin-derived languages are spoken. According to the Latin American Society of Nephrology and Hypertension/ Sociedad Latino Americana de Nefrologia e Hipertensión (SLANH), the acceptance rate for renal replacement therapy is 103 new patients per million population. In Latin America, hemodialysis is the predominant form of replacement therapy for end-stage renal disease; however, some countries employ peritoneal dialysis (PD) in 30% or more patients. In particular, Mexico is the country with the largest PD utilization in the world, and furthermore, it is estimated that approximately 25% of the world's PD population may be found Latin America. Data concerning clinical practice and long-term outcome of PD in Latin America are scarce, although regional registries are increasing in number and quality. In this review article, we present an overview of the situation of PD in several countries of Latin America, based on the registry of the SLAHN, national registries, and personal communication with PD experts from different countries.

Improving Outcome of Capd: Twenty-Five Years’ Experience in a Single Korean Center

Background

Continuous ambulatory peritoneal dialysis (CAPD) is an established treatment for end-stage renal disease (ESRD). We investigated the outcome of CAPD over a period of 25 years at our institution.

Methods

CAPD has been performed in 2301 patients in 25 years. After excluding patients with less than 3 months of follow-up and missing data, we evaluated 1656 patients who started peritoneal dialysis between November 1981 and December 2005. Data for sex, age, primary disease, co-morbidities, follow-up duration, cause of death, and cause of technique failure were collected. We also examined data for urea kinetic modeling (UKM), beginning in 1990, and peritonitis episodes, including causative organisms, starting in 1992.

Results

Compared to incident patients from 1981 – 1992, mean age and incidence of ESRD caused by diabetic nephropathy increased in patients from 1993 to 2005. Technique survival after 5 and 10 years was 71.9% and 48.1% respectively. Technique survival was significantly higher in patients who started CAPD after 1992 than in those who started before 1992. Peritonitis was the main reason for technique failure. Overall peritonitis rate was 0.38 episodes per patient-year, with a significant downward trend to 0.29 per patient-year over 10 years, corresponding to a decrease in gram-positive peritonitis. Patient survival after 5 and 10 years was 69.8% and 51.8% respectively. Patient survival improved significantly during 1992 – 2005 compared to 1981 – 1992 after adjustment for age, gender, diabetes, and cardiovascular comorbidities [hazard ratio (HR) 0.68, p < 0.01]. Subgroup analysis based on UKM revealed that dialysis adequacy did not affect patient survival. However, diabetes (HR 2.78, p < 0.001), older age (per 1 year: HR 1.06; p < 0.001), serum albumin level (per 1 g/dL: increase, HR 0.52; p < 0.05), and cardiovascular comorbidities (HR 2.32, p < 0.01) were identified as significant risk factors.

Conclusion

Technique survival has improved due partly to a decrease in peritonitis, which was attributed to a decrease in gram-positive peritonitis. Patient survival has also improved considering increases in aged patients and ESRD caused by diabetes. The mortality rate of CAPD is still high in older, diabetic, malnourished, and cardiovascular diseased patients. A more careful management of higher risk groups will be needed to improve the outcome of CAPD patients in the future.

Risk factors and outcomes of high peritonitis rate in continuous ambulatory peritoneal dialysis patients: A retrospective study

Peritonitis remains a major complication of peritoneal dialysis (PD). A high peritonitis rate (HPR) affects continuous ambulatory peritoneal dialysis (CAPD) patients' technique survival and mortality. Predictors and outcomes of HPR, rather than the first peritonitis episode, were rarely studied in the Chinese population. In this study, we examined the risk factors associated with HPR and its effects on clinical outcomes in CAPD patients.This is a single center, retrospective, observational cohort study. A total of 294 patients who developing at least 1 episode of peritonitis were followed up from March 1st, 2002, to July 31, 2014, in our PD center. Multivariate logistic regression was used to determine the factors associated with HPR, and the Cox proportional hazard model was conducted to assess the effects of HPR on clinical outcomes.During the study period of 2917.5 patient-years, 489 episodes of peritonitis were recorded, and the total peritonitis rate was 0.168 episodes per patient-year. The multivariate analysis showed that factors associated with HPR include a quick occurrence of peritonitis after CAPD initiation (shorter than 12 months), and a low serum albumin level at the start of CAPD. In the Cox proportional hazard model, HPR was a significant predictor of technique failure. There were no differences between HPR and low peritonitis rate (LPR) group for all-cause mortality. However, when the peritonitis rate was considered as a continuous variable, a positive correlation was observed between the peritonitis rate and mortality.We found the quick peritonitis occurrence after CAPD and the low serum albumin level before CAPD were strongly associated with an HPR. Also, our results verified that HPR was positively correlated with technique failure. More importantly, the increase in the peritonitis rate suggested a higher risk of all-cause mortality.These results may help to identify and target patients who are at higher risk of HPR at the start of CAPD and to take interventions to reduce peritonitis incidence and improve clinical outcomes.

The Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS): Unifying Efforts to Inform Practice and Improve Global Outcomes in Peritoneal Dialysis

♦

BACKGROUND

Extending technique survival on peritoneal dialysis (PD) remains a major challenge in optimizing outcomes for PD patients while increasing PD utilization. The primary objective of the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) is to identify modifiable practices associated with improvements in PD technique and patient survival. In collaboration with the International Society for Peritoneal Dialysis (ISPD), PDOPPS seeks to standardize PD-related data definitions and provide a forum for effective international collaborative clinical research in PD. ♦

METHODS

The PDOPPS is an international prospective cohort study in Australia, Canada, Japan, the United Kingdom (UK), and the United States (US). Each country is enrolling a random sample of incident and prevalent patients from national samples of 20 to 80 sites with at least 20 patients on PD. Enrolled patients will be followed over an initial 3-year study period. Demographic, comorbidity, and treatment-related variables, and patient-reported data, will be collected over the study course. The primary outcome will be all-cause PD technique failure or death; other outcomes will include cause-specific technique failure, hospitalizations, and patient-reported outcomes. ♦

RESULTS

A high proportion of the targeted number of study sites has been recruited to date in each country. Several ancillary studies have been funded with high momentum toward expansion to new countries and additional participation. ♦

CONCLUSION

The PDOPPS is the first large, international study to follow PD patients longitudinally to capture clinical practice. With data collected, the study will serve as an invaluable resource and research platform for the international PD community, and provide a means to understand variation in PD practices and outcomes, to identify optimal practices, and to ultimately improve outcomes for PD patients.

Vitamin D can ameliorate chlorhexidine gluconate-induced peritoneal fibrosis and functional deterioration through the inhibition of epithelial-to-mesenchymal transition of mesothelial cells

BACKGROUND

Peritoneal dialysis (PD) can induce fibrosis and functional alterations in PD patients' peritoneal membranes, due to long-term unphysiological dialysate exposure, partially occurring via triggering of epithelial-to-mesenchymal transition (EMT) in peritoneal mesothelial cells (MCs). Vitamin D can ameliorate these negative effects; however, the mechanism remains unexplored. Therefore, we investigated its possible links to MCs EMT inhibition.

METHODS

Peritoneal fibrosis was established in Sprague-Dawley rats by chlorhexidine gluconate (CG) intraperitoneal injection for 21 days, with and without 1α,25(OH)2D3 treatment. Morphological and functional evaluation and western blot analysis of EMT marker were performed upon peritoneum tissue. In vitro study was also performed in a primary human peritoneal MC culture system; MCs were incubated with transforming growth factor-β1 (TGF-β1) in the absence or presence of 1α,25(OH)2D3. EMT marker expression, migration activities, and cytoskeleton redistribution of MCs were determined.

RESULTS

1α,25(OH)2D3 ameliorated CG-induced morphological and functional deterioration in animal model, along with CG-induced upregulation of α-SMA and downregulation of E-cadherin expression. Meanwhile, 1α,25(OH)2D3 also ameliorated TGF-β1-induced decrease in E-cadherin expression, increase in Snai1 and α-SMA expression, intracellular F-actin redistribution, and migration activity in vitro.

CONCLUSION

1α,25(OH)2D3 can ameliorate CG-induced peritoneal fibrosis and attenuate functional deterioration through inhibiting MC EMT.

Impact of continuous quality improvement initiatives on clinical outcomes in peritoneal dialysis

OBJECTIVE

We evaluated the role of a quality improvement initiative in improving clinical outcomes in peritoneal dialysis (PD).

METHODS

In a retrospective analysis of 6 years of data from a hospital registry, the period between 1 July 2005 and 30 June 2008 (control group) provided baseline data from before implementation of systemic outcomes monitoring, and the period between 1 July 2008 and 30 June 2011 [continuous quality improvement (CQI) group] represented the time when a CQI program was in place. Peritonitis incidence, patient and technique survival, cardiovascular status, causes of death, and drop-out were compared between the groups.

RESULTS

In the 370 patients of the CQI group and the 249 patients of the control group, the predominant underlying kidney diseases were chronic glomerulonephritis and diabetic nephropathy. After implementation of the CQI initiative, the peritonitis rate declined to 1 episode in 77.25 patient-months from 1 episode in 22.86 patient-months. Ultrasound parameters of cardiac structure were generally unchanged in the CQI group, but significant increases in cardiothoracic ratio and interventricular septal thickness were observed in the control group (both p < 0.05). Patient survival at 1, 2, and 3 years was significantly higher in the CQI group (97.3%, 96.3%, and 96.3% respectively) than in the control group (92.6%, 82.4%, and 67.3% respectively, p < 0.001). Implementation of the CQI initiative also appeared to significantly improve technique survival rates: 95.6%, 92.6%, and 92.6% in the CQI group compared with 89.6%, 79.2%, and 76.8% in the control group (p < 0.001) after 1, 2, and 3 years respectively.

CONCLUSION

Integration of a CQI process into a PD program can significantly improve the quality of therapy and its outcomes.

Key factors for a high-quality peritoneal dialysis program--the role of the PD team and continuous quality improvement

The proportion of end-stage renal disease (ESRD) patients on peritoneal dialysis (PD) has increased very fast in China over the last decade. Renji Hospital, affiliated with Shanghai Jiaotong University School of Medicine, is a recognized high-quality PD unit with a high PD utilization rate, excellent patient and technique survival (1-year and 5-year patient survival rate of 93% and 71%, and 1-year and 5-year technique survival of 96% and 82%, respectively), low peritonitis rate and a well-documented good quality of life of the treated patients. We believe that a dedicated and experienced PD team, a structured patient training program, continuous patient support, establishing and utilizing standardized protocols, starting PD with low dialysis dose, monitoring key performance indicators (KPIs), and continuous quality improvement (CQI) are the key factors underlying this successful PD program.

Focus on peritoneal dialysis training: working to decrease peritonitis rates

Patient training has widely been considered to be one of the most critical factors for achieving optimal peritoneal dialysis clinical outcomes, including avoidance of peritonitis. However, research in this important area has been remarkably scant to date. This article will critically review the clinical evidence underpinning PD patient training and will specifically focus on four key areas: who should provide training and how, when and where should it be performed to obtain the best results. Evidence gaps and future research directions will also be discussed.

Shorter daily dwelling time in peritoneal dialysis attenuates the epithelial-to-mesenchymal transition of mesothelial cells

Background

Peritoneal dialysis (PD) therapy is known to induce morphological and functional changes in the peritoneal membrane. Long-term exposure to conventional bio-incompatible dialysate and peritonitis is the main etiology of inflammation. Consequently, the peritoneal membrane undergoes structural changes, including angiogenesis, fibrosis, and hyalinizing vasculopathy, which ultimately results in technique failure. The epithelial-to-mesenchymal transition (EMT) of mesothelial cells (MCs) plays an important role during the above process; however, the clinical parameters associated with the EMT process of MCs remain to be explored.

Methods

To investigate the parameters impacting EMT during PD therapy, 53 clinical stable PD patients were enrolled. EMT assessments were conducted through human peritoneal MCs cultured from dialysate effluent with one consistent standard criterion (MC morphology and the expression of an epithelial marker, cytokeratin 18). The factors potentially associated with EMT were analyzed using logistic regression analysis. Primary MCs derived from the omentum were isolated for the in vitro study.

Results

Forty-seven percent of the patients presented with EMT, 28% with non-EMT, and 15% with a mixed presentation. Logistic regression analysis showed that patients who received persistent PD therapy (dwelling time of 24 h/day) had significantly higher EMT tendency. These results were consistent in vitro.

Conclusions

Dwelling time had a significant effect on the occurrence of EMT on MCs.

Rat adipose tissue-derived stem cells attenuate peritoneal injuries in rat zymosan-induced peritonitis accompanied by complement activation

BACKGROUND AIMS

In patients receiving peritoneal dialysis, fungal or yeast peritonitis has a poor prognosis. In rat peritoneum with mechanical scraping, severe peritonitis can be induced by zymosan, a component of yeast (Zy/scraping peritonitis). Administration of rat adipose tissue-derived stromal cells (ASCs) potentially can improve several tissue injuries. The present study investigated whether rat ASCs could improve peritoneal inflammation in Zy/scraping peritonitis.

METHODS

Rat ASCs were injected intraperitoneally on a daily basis in rats with Zy/scraping peritonitis.

RESULTS

Peritoneal inflammation accompanied by accumulation of inflammatory cells and complement deposition was suppressed by day 5 after injection of rat ASCs. The peritoneal mesothelial layer in Zy/scraping peritonitis with rat ASC treatment was restored compared with the peritoneal mesothelial layer without rat ASC treatment. Injected rat ASCs co-existed with mesothelial cells in the sub-peritoneal layer. In vitro assays showed increased cellular proliferation of rat mesothelial cells combined with rat ASCs by co-culture assays, confirming that fluid factors from rat ASCs might play some role in facilitating the recovery of rat mesothelial cells. Hepatocyte growth factor was released from rat ASCs, and administration of recombinant hepatocyte growth factor increased rat mesothelial cell proliferation.

CONCLUSIONS

Because the peritoneal mesothelium shows strong expression of membrane complement regulators such as Crry, CD55 and CD59, restoration of the mesothelial cell layer by rat ASCs might prevent deposition of complement activation products and ameliorate peritoneal injuries. This study suggests the therapeutic possibilities of intraperitoneal rat ASC injection to suppress peritoneal inflammation by restoring the mesothelial layer and decreasing complement activation in fungal or yeast peritonitis.

Views of Japanese patients on the advantages and disadvantages of hemodialysis and peritoneal dialysis

PURPOSE

The preference for dialysis modalities is not well understood in Japan. This study explored the subjective views of Japanese patients undergoing dialysis regarding their treatments.

METHODS

The participants were receiving in-center hemodialysis (CHD) or continuous ambulatory peritoneal dialysis (CAPD). In Study 1, 34 participants (17 CHD and 17 CAPD) were interviewed about the advantages and disadvantages of dialysis modalities. In Study 2, 454 dialysis patients (437 CHD and 17 CAPD) rated the advantages and disadvantages of CHD and CAPD in a cross-sectional survey.

RESULTS

Interviews showed that professional care and dialysis-free days were considered as advantages of CHD, while independence, less hospital visits, and flexibility were considered as advantages of CAPD. Disadvantages of CHD included restriction of food and fluids and unpleasant symptoms after each dialysis session. Catheter care was an additional disadvantage of CAPD. Survey showed that the highly ranked advantages were professional care in CHD and less frequent hospital visits in CAPD, while the highly ranked disadvantages were concerns about emergency and time restrictions in CHD, and catheter care and difficulty in soaking in a bath in CAPD. The total scores of advantages and disadvantages showed that CHD patients subjectively rated their own modality better CHD over CAPD, while CAPD patients had the opposite opinion.

CONCLUSIONS

The results of this study indicate that the factors affecting the decision-making process of Japanese patients are unique to Japanese culture, namely considering the trouble caused to the people around patients (e.g., families, spouses, and/or caregivers).

The Singapore General Hospital Peritoneal Dialysis Programme from 2000–2008

Introduction:

There is lack of data regarding outcomes of peritoneal dialysis (PD) in Singapore. The aim of this study is to retrospectively evaluate the patient characteristics, technique survival, and patient survival in a single centre.

Methods:

The retrospective review included 1,015 adults (47.3% female, 72.6% Chinese, mean age 58±12.4 years, mean follow-up 39.7±27.7 months) initiated on PD at the Singapore General Hospital from January 2000 to December 2008. Baseline characteristics, including cause of end-stage renal disease (ESRD), comorbid conditions, and endpoints (ie. death, transfer to HD or transplantation, renal recovery or until last follow-up on 31 December 2010) were collected. Demographic variables and patient and technique survival rates were analysed.

Results:

The main causes of ESRD were diabetes mellitus (DM) (58.0%), glomerulonephritis (GN) (23.3%) and hypertension (15.4%). The 1, 2, 5 and 10-year patient survival rates were 88.7%, 77.7%, 39.8% and 15.4%, respectively. Causes of death were related to infection (43.1%) and cardiac (37.8%). Patient survival rates were significantly better in PD patients with ESRD due to GN, compared with DM (5-year survival rates of 70.2% versus 22.3%, P <0.001). Patients aged 65 years and older had lower survival rates compared with those aged less than 65 years ( P <0.001). The 1, 2, 5 and 10-year technique survival rates were 92.9%, 85.0%, 64.8% and 32.9%, respectively. Peritonitis was the main cause of technique failure (63.5%), and caused 13.8% of deaths. Technique survival rates were better in patients with ESRD due to GN, compared with DM (5-year survival rates of 70.9% versus 62.0%, P <0.05).

Conclusion:

In our single-centre retrospective review, technique survival was comparable to other East Asian centres. The poorer patient survival observed in this study may be due to older age and higher comorbidity.

Encapsulating peritoneal sclerosis: incidence, predictors, and outcomes

Encapsulating peritoneal sclerosis is a complication of peritoneal dialysis characterized by persistent, intermittent, or recurrent adhesive bowel obstruction. Here we examined the incidence, predictors, and outcomes of encapsulating peritoneal sclerosis (peritoneal fibrosis) by multivariate logistic regression in incident peritoneal dialysis patients in Australia and New Zealand. Matched case-control analysis compared the survival of patients with controls equivalent for age, gender, diabetes, and time on peritoneal dialysis. Of 7618 patients measured over a 13-year period, encapsulating peritoneal sclerosis was diagnosed in 33, giving an incidence rate of 1.8/1000 patient-years. The respective cumulative incidences of peritoneal sclerosis at 3, 5, and 8 years were 0.3, 0.8, and 3.9%. This condition was independently predicted by younger age and the duration of peritoneal dialysis, but not the rate of peritonitis. Twenty-six patients were diagnosed while still on peritoneal dialysis. Median survival following diagnosis was 4 years and not statistically different from that of 132 matched controls. Of the 18 patients who died, only 7 were attributed directly to peritoneal sclerosis. Our study shows that encapsulating peritoneal sclerosis is a rare condition, predicted by younger age and the duration of peritoneal dialysis. The risk of death is relatively low and not appreciably different from that of competing risks for mortality in matched dialysis control patients.

Novel therapeutic option for refractory heart failure in elderly patients with chronic kidney disease by incremental peritoneal dialysis

BACKGROUND

Heart failure (HF) often accompanies chronic kidney disease (CKD) in the elderly. This clinical condition is a critical socio-medical issue, because high-dose diuretic therapy stimulates the renin-angiotensin-aldosterone axis and sympathetic nervous system outflow, and may thus result in vicious cycles of cardio-renal deterioration, leading to excess hospitalization and death. Peritoneal dialysis (PD) is a renal replacement therapy used for maintenance dialysis, and is characterized by the continuous removal of fluid. The present study examined the clinical feasibility and effects of a novel style of PD for elderly CKD patients with refractory HF.

METHODS

Twelve elderly CKD patients (stages 3-5) with refractory HF [New York Heart Association (NYHA) class III, n=9; IV, n=3; mean age, 81+/-6 years] received PD treatment. Patients had episodes of >3 hospitalizations in the previous year, and were initially treated with < or =19 sessions of sequential hemofiltration, followed by incremental PD, with 3 PD sessions/week (8h each) at the start, increasing in frequency and dwelling time as clinically indicated.

RESULTS

During follow-up (median, 26.5 months), PD was well tolerated by all patients, and no patients required hospitalization for HF. Three patients died due to non-HF-related events. All patients showed improvements in NYHA functional class (class I, n=9; class II, n=3) and significant decreases in the dose of diuretics prescribed (P<0.05). Kidney function stabilized, while significant improvements in end-diastolic left ventricular diameter (-5%, P<0.05) and hemoglobin count (+15%, P<0.05) were achieved. Brain natriuretic peptide (-46%) and aldosterone (-13%) levels tended to decrease.

CONCLUSIONS

Incremental PD could represent a novel therapeutic option for elderly patients with refractory HF. In addition to fluid removal by PD, correction of renal anemia, preservation of kidney function, and avoidance of high-dose diuretic therapy may play a role in maximizing clinical benefits.

Peritoneal Dialysis in Brazil: Twenty-Five Years of Experience in a Single Center

Objectives

To evaluate patient and technique survival and to provide an analysis of peritoneal dialysis (PD)-related peritonitis in 25 years of experience in a single center.

Study Design

Retrospective study of incident patients on PD from July 1980 to July 2005.

Setting

Single, university based, Brazilian dialysis program.

Patients

680 patients were analyzed in our study from July 1980 to July 2005, with a cumulative experience of 15303 patient-months. All patients over 15 years of age entering the dialysis program were included in the study. Patients with less than 30 days of follow-up were excluded. Biochemical and demographic variables, peritonitis episodes, and patient and technique survival were analyzed.

Results

Mean age at start of PD was 53 ± 16 years; diabetic nephropathy was the main cause of chronic kidney disease. Cardiovascular disease was the main cause of death (44%); peritonitis was responsible for 16% of fatal events. The predictors of death in our study were diabetes [relative risk (RR) 1.23, p < 0.01], advanced age (RR 1.58, p < 0.001), low serum albumin level (RR 1.25, p < 0.01), and low serum phosphate level (RR 1.39, p < 0.001) upon starting PD. There were 1048 cases of peritonitis over the 25-year period, with a significant reduction in incidence after the introduction of the double-bag system. The number of incident PD patients originating from hemodialysis increased threefold over the observation period ( p < 0.001), with a similar increase in comorbidities over time.

Conclusion

In the largest single-center report of PD experience in Latin America, we describe the overall rate and trends over time of peritonitis as well as patient and technique survival, which are similar to previous reports. Significant changes in peritonitis rates and causative organisms as well as a significant time-dependent increase in high-risk patients starting PD were observed.

Peritoneal membrane structural and functional changes during peritoneal dialysis

Peritoneal dialysis is now utilized as a renal replacement therapy modality in a substantial percentage of patients with end-stage renal disease, with excellent short-term patient and technique survival rates. However, the potential complications associated with longer-term therapy, such as ultrafiltration failure or encapsulating peritoneal sclerosis, have led to raise some concern about peritoneal dialysis as an adequate mode of treatment of end-stage renal disease in the long term. In the last decade, a substantial amount of information has been gathered on the characteristics of the peritoneal membrane at the onset of peritoneal dialysis, and on the anatomical and pathophysiologic changes that occur with long-term peritoneal dialysis. I will review this subject with a special focus on the various strategies that can help protect the peritoneal membrane during peritoneal dialysis so as to allow peritoneal dialysis to succeed as a long-term dialysis modality.