Hemodialysis bilayer bionic blood vessels developed by the mechanical stimulation of hepatitis B viral X(HBX) gene- transfected hepatic stellate cells

Artificial vascular graft (AVG) fistula is widely used for hemodialysis treatment in patients with renal failure. However, it has poor elasticity and compliance, leading to stenosis and thrombosis. The ideal artificial blood vessel for dialysis should replicate the structure and components of a real artery, which is primarily maintained by collagen in the extracellular matrix (ECM) of arterial cells. Studies have revealed that in hepatitis B virus (HBV)-induced liver fibrosis, hepatic stellate cells (HSCs) become hyperactive and produce excessive ECM fibers. Furthermore, mechanical stimulation can encourage ECM secretion and remodeling of a fiber structure. Based on the above factors, we transfected HSCs with the hepatitis B viral X (HBX) gene for simulating the process of HBV infection. Subsequently, these HBX-HSCs were implanted into a polycaprolactone-polyurethane (PCL-PU) bilayer scaffold in which the inner layer is dense and the outer layer consists of pores, which was mechanically stimulated to promote the secretion of collagen nanofiber from the HBX-HSCs and to facilitate crosslinking with the scaffold. We obtained an ECM-PCL-PU composite bionic blood vessel that could act as access for dialysis after decellularization. Then, the vessel scaffold was implanted into a rabbit's neck arteriovenous fistula model. It exhibited strong tensile strength and smooth blood flow and formed autologous blood vessels in the rabbit's body. Our study demonstrates the use of human cells to create biomimetic dialysis blood vessels, providing a novel approach for creating clinical vascular access for dialysis.

Autophagy in peritoneal fibrosis

Peritoneal dialysis (PD) is a widely accepted renal replacement therapy for patients with end-stage renal disease (ESRD). Morphological and functional changes occur in the peritoneal membranes (PMs) of patients undergoing long-term PD. Peritoneal fibrosis (PF) is a common PD-related complication that ultimately leads to PM injury and peritoneal ultrafiltration failure. Autophagy is a cellular process of "self-eating" wherein damaged organelles, protein aggregates, and pathogenic microbes are degraded to maintain intracellular environment homeostasis and cell survival. Growing evidence shows that autophagy is involved in fibrosis progression, including renal fibrosis and hepatic fibrosis, in various organs. Multiple risk factors, including high-glucose peritoneal dialysis solution (HGPDS), stimulate the activation of autophagy, which participates in PF progression, in human peritoneal mesothelial cells (HPMCs). Nevertheless, the underlying roles and mechanisms of autophagy in PF progression remain unclear. In this review, we discuss the key roles and potential mechanisms of autophagy in PF to offer novel perspectives on future therapy strategies for PF and their limitations.

Epithelial-mesenchymal Transition of Peritoneal Mesothelial Cells Is Enhanced by M2c Macrophage Polarization

BACKGROUND

Peritoneal fibrosis (PF) can reduce the efficiency of peritoneal dialysis and eventually lead to ultrafiltration failure. Epithelial-mesenchymal transition (EMT) of peritoneal mesothelial cells (PMCs) is the start of PF. Macrophages are involved in the process. This study was to investigate the effect of macrophage polarization on EMT of PMCs.

METHODS

Monocyte-macrophage cells (THP-1) were treated to induce macrophage subsets (M1, M2a, M2c). The inducing was assessed by detecting protein and mRNA expression of cytokines using ELISA and RT-PCR. Subsequently, PMCs were co-cultured with M1, M2a and M2c, respectively, in Transwell chambers for 48 h and then expressions of E-cadherin and α-SMA were determined in PMCs. The PMCs that were not co-cultured with macrophages served as control PMCs. One-way ANOVA and SNK-q test were used to conduct statistics and P < .05 as significant.

RESULTS

Detection of the cytokines, including IL-6, IL-10, IL-12, TGF-β1, CCL17 and CXCL13, verified that the inducting of macrophage subtypes was successful. Compared to control, E-cadherin protein expression was significantly decreased and α-SMA protein expression increased in M1-treated PMCs (P < .05); M2a-treated PMCs had an increased gene expression of α-SMA (P < .05); E-cadherin protein and gene expression were decreased and α-SMA protein and gene expression increased significantly in M2c-treated PMCs (P < .05 or P < .01).

CONCLUSIONS

EMT of PMCs is enhanced by M2c macrophage polarization; meanwhile, M1 and M2a polarization may have the effect to some extent, but not as definite as M2c.

Peritoneal Dialysis Modality Failure in a Middle-Income Country: A Retrospective Cohort Study

Rationale & Objective

Technique failure in peritoneal dialysis (PD) remains one of the most critical challenges of this therapy and is associated with a significant increase in costs and morbidity. Our objective was to estimate the frequency of PD technique failure and identify factors associated with technique failure.

Study Design

A retrospective multicenter observational cohort study.

Setting & Participants

All adult patients initiating PD between January 1, 2010, and December 31, 2015, with follow-up until December 31, 2018, at the Renal Therapy Services network in Colombia.

Exposure & Predictors

PD modality (continuous ambulatory PD and automated PD) and demographic and clinical characteristics.

Outcomes

Technique failure, defined as a switch to hemodialysis lasting at least 30 days.

Analytical Approach

Sociodemographic and clinical characteristics of all patients were summarized descriptively according to modality. We estimated the cumulative incidence of technique failure, and a flexible parametric survival model with competing risks was used to evaluate factors associated with this outcome.

Results

Among 6,452 patients meeting inclusion criteria, 67% were treated with continuous ambulatory PD. The cumulative incidence of technique failure within 1 year of PD initiation adjusting for competing risks was 6.9% (95% CI, 6.3%-7.6%); within 2 years, technique failure was 13.5% (95% CI, 12.6%-14.4%); and within 3 years, 19.6% (95% CI, 18.5%-20.7%). Female sex, larger center size, and higher Kt/V were associated with lower risk for modality change, whereas diabetes, history of major abdominal surgery, catheter implant technique (laparotomy and percutaneous techniques), obesity, and peritonitis were associated with a higher likelihood of technique failure.

Limitations

Variables of distance to the center, use of icodextrin, and measures of outcomes reported by patients were not included.

Conclusions

Technique failure is relatively uncommon in Colombia; catheter-related problems are the most frequent cause of technique failure. Best practices in catheter insertion could minimize the risk for this outcome.

Peritoneal dialysis in incident patients with primary glomerulonephritis. Results of a 20-year multicenter registry study

BACKGROUND AND OBJECTIVES

Glomerulonephritis (GN) is one of the main causes of chronic terminal kidney disease; however, few studies assess its prognosis in dialysis. We analyze the survival and characteristics of patients on peritoneal dialysis (PD) with primary GN (PGN), and compare their results with other kidney patients.

METHODS

This prospective observational study took place from 1995 to 2014. We included all incident patients who were initiated on the technique in the Levante registry. Data were transferred to an anonymized database in Access. Statistical analysis was performed using SPSS software (version 19.0).

RESULTS

The study included 2243 patients, with GN representing the main cause of primary kidney disease (21,5%). IgA nephropathy was the most frequent histologically confirmed form of PGN. Compared with the rest of the sample, patients with PGN were more often men (65% vs 58%, p = .004), and they were on average younger (48 years vs 55 years, p < .001). They also had fewer comorbidities and a higher rate of inclusion on the waitlist for a kidney transplant (87 vs 63%, p < .001). Patients with PGN also had more transplants (48,9%, p < .001), and this was the most frequent reason for stopping PD; beyond that, their peritonitis mean rate was lower (0,34 vs 0,45 episodes/patient-year, p < .001). Technique survival was 90,6% at one year, 71,7% at 3 years, and 59,0% at 5 years (median 76,8 months); there were no differences between groups. Survival was 94,9% at one year, 80,1% at 3 years, and 63,7% at 5 years (median 90,7 months). Patients with PGN showed better mean survival than patients with other kidney pathologies (153,5 months [95% IC: 137,0-169,9] vs 110,3 months [95% CI: 100,8-119,7], p < .001). In the multivariable analysis, the main negative risk factor influencing technique survival was a higher peritoneal transport (p = .018). Factors with a negative influence on mortality were being older (p < .001) and having any comorbidity, mainly diabetes and liver disease (p < .001). By contrast, protective survival factors were inclusion on the transplant waitlist and a higher baseline residual renal function (p = .001).

CONCLUSIONS

PD has several advantages as a first dialytic treatment, and our results suggest that it is an excellent technique to manage patients with PGN while they await a kidney transplant.

Transforming Growth Factor β1 Induces Epithelial–mesenchymal Transition by Activating the Jnk–SMAD3 Pathway in Rat Peritoneal Mesothelial Cells

⋄ Background

Peritoneal fibrosis is a serious complication in long-term peritoneal dialysis (PD) patients. Epithelial-mesenchymal transition (EMT) plays an important role in peritoneal fibrosis, and TGFβ1 is the crucial inducer of EMT. Phosphorylation of Smad proteins is required for TGFβ1-induced EMT. It was reported that C-Jun N-terminal kinase (JNK) was involved in the TGFβ1/Smad signaling pathway and might regulate the activation of Smad proteins. However, whether JNK is activated by TGFβ1 in rat peritoneal mesothelial cells (RPMCs) and the role taken by JNK signaling in EMT induced by TGFβ1 remains undetermined. In the present study, we investigated the role of JNK-Smad pathway in EMT induced by TGFβ1 in RPMCs.

⋄ Methods

We harvested RPMCs from the peritoneum of male Sprague-Dawley rats and then cultured the cells in Dulbecco modified Eagle medium / F12 medium with 15% (volume:volume) fetal bovine serum. The cells were pretreated with SP600125, a specific inhibitor of JNK, for 4 hours before incubation with TGFβ1. The protein expression levels of phosphorylated JNK, Smad2, and Smad3 were detected by Western blotting. The messenger RNA levels and protein expression of α-smooth muscle actin (α-SMA), E-cadherin, and collagen I were determined with reverse transcriptase polymerase chain reaction and Western blotting respectively.

⋄ Results

Expression of α-SMA and collagen I were significantly increased and expression of E-cadherin decreased with TGFβ1 in RPMCs. Transforming growth factor β1 can stimulate phosphorylated JNK expression from 5 minutes, with the peak at 10 minutes, and phosphorylated Smad2 and Smad3 expression from 10 minutes, with the peak at 30 minutes. The addition of SP600125, which blocked activation of JNK, effectively inhibited TGFβ1-induced phosphorylation of Smad3, but not Smad2. Also, our results showed that SP600125 effectively suppressed TGFβ1-induced high expression of α-SMA and collagen I, and prevented TGFβ1-induced downregulation of E-cadherin expression in RPMCs.

⋄ Conclusions

This study demonstrated that JNK signaling may play an important role in EMT induced by TGFβ1 in RPMCs through activation of Smad3, suggesting that JNK inhibitor may prove to be a novel therapeutic agent for peritoneal fibrosis.

Immune Dysfunction in Dialysis Patients—Prevention and Treatment Strategies

Immune dysfunction, resulting in infection or inflammation, or both, is closely associated with poor clinical outcome in end-stage renal disease patients. So far, no single measure can effectively address this condition, because many factors, such as uremia per se and dialysis treatment are involved in the pathogenesis. Our review focuses on currently available treatments and prevention options, and identifies future research needs.

Peritoneal dialysis in incident patients with primary glomerulonephritis. Results of a 20-year multicenter registry study

BACKGROUND AND OBJECTIVES

Glomerulonephritis (GN) is one of the main causes of chronic terminal kidney disease; however, few studies assess its prognosis in dialysis. We analyze the survival and characteristics of patients on peritoneal dialysis (PD) with primary GN (PGN), and compare their results with other kidney patients.

METHODS

This prospective observational study took place from 1995 to 2014. We included all incident patients who were initiated on the technique in the Levante registry. Data were transferred to an anonymized database in Access. Statistical analysis was performed using SPSS software (version 19.0).

RESULTS

The study included 2,243 patients, with GN representing the main cause of primary kidney disease (21,5%). IgA nephropathy was the most frequent histologically confirmed form of PGN. Compared with the rest of the sample, patients with PGN were more often men (65% vs 58%, P=.004), and they were on average younger (48 years vs 55 years, P<.001). They also had fewer comorbidities and a higher rate of inclusion on the waitlist for a kidney transplant (87 vs 63%, P<.001). Patients with PGN also had more transplants (48,9%, P<.001), and this was the most frequent reason for stopping PD; beyond that, their peritonitis mean rate was lower (0,34 vs 0,45 episodes/patient-year, P<.001). Technique survival was 90,6% at one year, 71,7% at 3 years, and 59,0% at 5 years (median 76,8 months); there were no differences between groups. Survival was 94,9% at one year, 80,1% at 3 years, and 63,7% at 5 years (median 90,7 months). Patients with PGN showed better mean survival than patients with other kidney pathologies (153,5 months [95% IC: 137,0 to 169,9] vs 110,3 months [95% CI: 100,8 to 119,7], P<.001). In the multivariable analysis, the main negative risk factor influencing technique survival was a higher peritoneal transport (P=.018). Factors with a negative influence on mortality were being older (P <.001) and having any comorbidity, mainly diabetes and liver disease (P <.001). By contrast, protective survival factors were inclusion on the transplant waitlist and a higher baseline residual renal function (P=.001).

CONCLUSIONS

PD has several advantages as a first dialytic treatment, and our results suggest that it is an excellent technique to manage patients with PGN while they await a kidney transplant.

Contribution of Early Failure to Outcome on Peritoneal Dialysis

Background

The technique failure rate on peritoneal dialysis (PD) remains high despite technical progress. There are no data concerning the contribution of early failure to outcome on PD.

Aim

To analyze the importance of early treatment failure in PD and to compare early with late failures with respect to reasons and predictors of risk for failure.

Methods

We performed a retrospective study of all patients admitted for PD from October 1983 to June 2005. The end point was PD failure-free survival. Differences between reasons for failure with respect to early (within 6 months) and late failure were analyzed. Multivariate associations of baseline covariates with early and late failure were investigated.

Results

We included 279 patients. 153 (55%) patients experienced PD failure: 97 (63%) of them had technique failure; 56 (37%) patients died due to non-PD-related causes. 29% ( n = 44) of all PD failures and 40% ( n = 39) of all technique failures occurred within 6 months. Catheter and psychosocial problems contributed more often to early than to late failure, whereas infections, leakages, and hernias contributed equally to early and late failure. Death was the predominant reason for late failure. Female sex was a risk factor for early failure and older age a risk factor for late failure. Higher cholesterol levels were associated with a decreased risk for both early and late failure.

Conclusion

The contribution of early failure to outcome on PD is important, as one third of all PD failures and 40% of all technique failures may occur within the first 6 months, as shown in our study. Due to the retrospective nature and the single-center character, the results cannot be generalized. However, it is important to enhance recognition of patients at high risk for early PD failure prior to initiation of PD, in order to avoid unnecessary surgical interventions and medical complications, and for rational resource allocation.

Changes in Causative Organisms and Their Antimicrobial Susceptibilities in Capd Peritonitis: A Single Center's Experience over one Decade

Background

In recent years, the rate of peritonitis during continuous ambulatory peritoneal dialysis (CAPD) has been significantly reduced. However, peritonitis remains a major complication of CAPD, accounting for considerable mortality and hospitalization among CAPD patients.

Objective

To generate a “center tailored” treatment protocol for CAPD peritonitis by examining the changes of causative organisms and their susceptibilities to antimicrobial agents over the past 10 years.

Method

Retrospective review of the medical records of 1015 CAPD patients (1108 episodes of peritonitis) who were followed up from 1992 through 2001.

Results

The overall incidence of peritonitis was 0.40 episodes/patient-year. The annual rate of peritonitis and the incidence of peritonitis caused by a single gram-positive organism were significantly higher in 1992 and 1993 compared with those in the rest of the years ( p < 0.05). The incidence of peritonitis due to coagulase-negative staphylococcus (CoNS) decreased significantly over time, whereas there was no significant change in the incidence of Staphylococcus aureus (SA)-induced peritonitis. Among CoNS, resistance to methicillin increased from 18.4% in 1992 – 1993 to 41.7% in 2000 – 2001 ( p < 0.05). In contrast, the incidence of methicillin-resistant SA was not different according to the calendar year. Catheter removal rates were significantly higher in peritonitis due to a single gram-negative organism (16.6%) compared with gram-positive peritonitis (4.8%, p < 0.005). The mortality associated with peritonitis was also higher in gram-negative (3.7%) compared with gram-positive peritonitis (1.4%), but there was no statistical significance. Among single gram-positive organism-induced peritonitis, catheter removal rates were significantly higher in SA (9.3%) than those in CoNS (2.9%, p < 0.01) and other gram-positive organisms (2.9%, p < 0.05). In peritonitis caused by CoNS, the methicillin-resistant group showed significantly higher removal rates than the methicillin-susceptible group (8.2% vs 1.0%, p < 0.01).

Conclusion

The incidence of peritonitis for 2001 decreased to less than half that for 1992, due mainly to a significant decrease in CoNS-induced peritonitis, whereas the proportions of peritonitis due to a single gram-negative organism and methicillin-resistant CoNS increased. These findings suggest that it is necessary to prepare new center-based guidelines for the initial empirical treatment of CAPD peritonitis.

Fluoroscopically Guided Peritoneal Dialysis Catheter Placement: Long-Term Results from a Single Center

Objective

Despite percutaneous fluoroscopy ensuring appropriate placement of peritoneal dialysis (PD) catheters, the efficacy of this method is not well known. Therefore, we evaluated our long-term experience with fluoroscopy-assisted placement of PD catheters.

Patients and Methods

We retrospectively reviewed 134 PD catheters in 114 PD patients that were treated in the PD center of a university-based hospital. We evaluated complications related to PD catheters, causes for catheter removal, and catheter survival. We used the multivariate Cox proportional hazard model to identify independent factors related to PD catheter survival.

Results

Early complications related to insertion included 1 case of pericatheter bleeding; there were no placement failures. Early complications occurred in 8.5% of patients. Most late complications were migration and leakage, which occurred in 10.4% and 9.7% of patients respectively. The most common cause for catheter removal was intractable and recurrent peritonitis. The 12- and 24-month survival rates of the catheters were 80.0% and 74.9%. The most significant prognostic factor of percutaneous fluoroscopy-assisted PD catheter survival was late leakage ( p < 0.01).

Conclusions

In addition to the advantages of simplicity, minimal invasiveness, and relative safety, the survival rate of PD catheters placed using the percutaneous fluoroscopy-assisted method was comparable to that of more invasive methods. Percutaneous fluoroscopy-assisted placement of PD catheters should be considered when available, and may be preferred to other placement methods.

Perspectives in renal replacement therapy: Haemodialysis

Haemodialysis (HD) was the first procedure that had demonstrated the ability to partially replace renal function, and became the most widely utilized treatment for patients with end-stage renal disease (ESRD). In a great majority of countries around the world, conventional in-centre HD had become the predominant renal replacement therapy, being touted as able to achieve better solute clearance and more successful in attaining euvolemia than patients on peritoneal dialysis. This is despite the antecedent hemodynamic risks, more rapid loss of residual renal function, greater infectious perils, excessive erythropoietin requirements and higher infrastructure costs. In addition, quality of life had been suggested to be worse among patients on HD, though this had been challenged repeatedly. Consequently, the concept of integrated ESRD care over the last few decades had placed HD, as a complementary rather than a competitive treatment modality to the entire armamentarium of renal replacement therapies. Incorporating HD as part of integrated care into health-care policies and national resource planning will become an essential strategy in improving access and outcome to care among the ESRD population. The improvement in technologies and innovation in prescription had brought forth enhanced dialyzer membrane and machine upgrades, and expanded modalities including more frequent HD and haemodiafiltration. While boasting of controversial improvement in outcomes, many of these therapies remain expensive and insurmountable for widespread utility in many countries. In addition, the results of these new technologies had been conflicting across studies, with some even suggesting that they could be detrimental. Therefore, judicial consideration has to be undertaken to appropriate their use in clinical practice.

Peritoneal Infections in Children Undergoing Acute Peritoneal Dialysis at a Tertiary/Quaternary Central Hospital in Kwazulu-Natal, South Africa

Background

In a resource-limited setting, acute peritoneal dialysis (APD) is the modality of choice as a form of renal replacement therapy in children with acute kidney injury (AKI). However, there is a high risk of peritonitis that causes significant morbidity and mortality. Data on PD and peritonitis in developing countries are scarce. The purpose of this retrospective study was to determine the prevalence of APD-related peritonitis at a central referral hospital in KwaZulu-Natal, South Africa.

Methods

A retrospective study from January 2010 until December 2014 was done at Inkosi Albert Luthuli Central Hospital (IALCH). All children under the age of 13 years with AKI requiring APD were included in the study.

Results

Forty children were included in the study. Age ranged from 0.2 years to 12.25 years; 25 (62.5%) were male and 15 (37.5%) female. Twenty-seven (67.5%) were admitted to the intensive care unit (ICU) and 13 (32.5%) to the pediatric high care ward. Septicemia with multi-organ dysfunction was the was the main cause of AKI requiring APD in 18 (45%) children followed by poststreptococcal glomerulonephritis in 8 (20%). Acute PD was complicated by culture-proven peritonitis in 19 (47.5%) children of whom 16 (84.2%) had a single organism cultured while in 3, (15.7%) there was a mixed culture. The total number of organisms cultured was 24: 8 (33.3%) were gram-positive organisms, 12 (50%) gram-negative organisms, and 4 (16.67%) fungal. The Paediatric Index of Mortality (PIM) 2 Score risk of mortality was 99.4% for patients admitted to ICU. Mortality rate was 65%, and 14 (53%) of the children who demised had peritonitis.

Conclusion

This study showed an inordinately high complication rate of peritonitis, mostly secondary to gram-negative organisms, of children undergoing APD in a central referral hospital. The use of surgically placed, tunneled catheters, meticulous attention to aseptic techniques and judicious use of antimicrobials is highly recommended in reducing the incidence of peritonitis in children undergoing APD.

Rosiglitazone, a Peroxisome Proliferator-Activated Receptor (PPAR)-γ Agonist, Attenuates Inflammation Via NF-κB Inhibition in Lipopolysaccharide-Induced Peritonitis

We assessed the anti-inflammatory effect of peroxisome proliferator-activated receptor (PPAR)-γ agonist, rosiglitazone, in a lipopolysaccharide (LPS)-induced peritonitis rat model. LPS was intraperitoneally injected into rats to establish peritonitis model. Male Sprague-Dawley (SD) rats were assigned to normal saline (the solvent of LPS), LPS, rosiglitazone plus LPS, and rosiglitazone alone. A simple peritoneal equilibrium test was performed with 20 ml 4.25 % peritoneal dialysis fluid. We measured the leukocyte count in dialysate and ultrafiltration volume. Peritoneal membrane histochemical staining was performed, and peritoneal thickness was assessed. CD40 and intercellular adhesion molecule-1 messenger RNA (ICAM-1 mRNA) levels in rat visceral peritoneum were detected by reverse transcription (RT)-PCR. IL-6 in rat peritoneal dialysis effluent was measured using enzyme-linked immunosorbent assay. The phosphorylation of NF-κB-p65 and IκBα was analyzed by Western blot. LPS administration resulted in increased peritoneal thickness and decreased ultrafiltration volume. Rosiglitazone pretreatment significantly decreased peritoneal thickness. In addition to CD40 and ICAM-1 mRNA expression, the IL-6, p-p65, and p-IκBα protein expressions were enhanced in LPS-administered animals. Rosiglitazone pretreatment significantly decreased ICAM-1 mRNA upregulation, secretion of IL-6 protein, and phosphorylation of NF-κB-p65 and IκBα without decreasing CD40 mRNA expression. Rosiglitazone has a protective effect in peritonitis, simultaneously decreasing NF-κB phosphorylation, suggesting that NF-κB signaling pathway mediated peritoneal inflammation induced by LPS. PPAR-γ might be considered a potential therapeutic target against peritonitis.

HL156A, a novel AMP-activated protein kinase activator, is protective against peritoneal fibrosis in an in vivo and in vitro model of peritoneal fibrosis

HL156A is a novel AMP-activated protein kinase (AMPK) activator. We aimed to investigate the protective mechanism of HL156A against peritoneal fibrosis (PF) in in vivo and in vitro models. The rat PF model was induced by daily intraperitoneally injection of chlorhexidine (CHX) solution containing 0.1% CHX gluconate and 15% ethanol for 4 wk. The rats in the treatment group were treated with HL156A (1 mg·kg−1·day−1). Control rats were injected with vehicle alone. In vitro, cultured rat peritoneal mesothelial cells (RPMCs) were treated with either high glucose (HG; 50 mM), normal glucose (NG; 5 mM), NG+HL156A, or HG+HL156A. HL156A in supplemented rats ameliorated peritoneal calcification, cocoon formation, bowel obstruction, and PF. Immunohistochemistry showed reduced fibronectin accumulation in the peritoneum of HL156A-treated rats compared with those injected with CHX alone. HL156A treatment of RPMCs inhibited HG-induced myofibroblast transdifferentiation and markers of epithelial-mesenchymal transition (EMT). Moreover, HL156A ameliorated HG-induced transforming growth factor-β1, Smad3, Snail, and fibronectin expression in the RPMCs via AMPK upregulation. These results suggest that HL156A exhibits a protective effect in PF progression. Further research is warranted to seek the therapeutic potential of HL156A as an antifibrotic agent in peritoneal dialysis patients.

A Global Overview of the Impact of Peritoneal Dialysis First or Favored Policies: An Opinion

Given the ever-increasing burden of end-stage renal disease (ESRD) in a global milieu of limited financial and health resources, interested parties continue to search for ways to optimize dialysis access. Government and payer initiatives to increase access to renal replacement therapies (RRTs), particularly peritoneal dialysis (PD) and hemodialysis (HD), may have meaningful impacts from clinical and health-economic perspectives; and despite similar clinical and humanistic outcomes between the two dialysis modalities, PD may be the more convenient and resource-conscious option. This review assessed country-specific PD-First/Favored policies and their associated background, implementation, and outcomes. It was found that barriers to policy-implementation are broadly associated with government policy, economics, provider or healthcare professional education, modality-related factors, and patient-related factors. Notably, the success of a given country's PD-Favored policy was inversely associated with the extent of HD infrastructure. It is hoped that this review will provide a foundation across countries to share lessons learned during the development and implementation of PD-First/Favored policies.

Janus kinase signaling activation mediates peritoneal inflammation and injury in vitro and in vivo in response to dialysate

Peritoneal membrane pathology limits long-term peritoneal dialysis (PD). Here, we tested whether JAK/STAT signaling is implicated and if its attenuation might be salutary. In cultured mesothelial cells, PD fluid activated, and the pan-JAK inhibitor P6 reduced, phospho-STAT1 and phospho-STAT3, periostin secretion, and cleaved caspase-3. Ex vivo, JAK was phosphorylated in PD effluent cells from long-term but not new PD patients. MCP-1 and periostin were increased in PD effluent in long term compared with new patients. In rats, twice daily, PD fluid infusion induced phospho-JAK, mesothelial cell hyperplasia, inflammation, fibrosis, and hypervascularity after 10 days of exposure to PD fluid. Concomitant instillation of a JAK1/2 inhibitor virtually completely attenuated these changes. Thus, our studies directly implicate JAK/STAT signaling in the mediation of peritoneal membrane pathology as a consequence of PD.

A20 overexpression inhibits lipopolysaccharide-induced NF-κB activation, TRAF6 and CD40 expression in rat peritoneal mesothelial cells

Zinc finger protein A20 is a key negative regulator of inflammation. However, whether A20 may affect inflammation during peritoneal dialysis (PD)-associated peritonitis is still unclear. This study was aimed to investigate the effect of A20 overexpression on lipopolysaccharide (LPS)-induced inflammatory response in rat peritoneal mesothelial cells (RPMCs). Isolated and cultured RPMCs in vitro. Plasmid pGEM-T easy-A20 was transfected into RPMCs by Lipofectamine™2000. The protein expression of A20, phospho-IκBα, IκBα, TNF receptor-associated factor (TRAF) 6 and CD40 were analyzed by Western blot. The mRNA expression of TRAF6, CD40, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were determined by real time-PCR. NF-κB p65 DNA binding activity, IL-6 and TNF-α levels in cells culture supernatant were determined by ELISA. Our results revealed that RPMCs overexpression of A20 lead to significant decrease of LPS-induced IκBα phosphorylation and NF-κB DNA binding activity (all p<0.01). In addition, A20 also attenuated the expression of TRAF6, CD40, IL-6 and TNF-α as well as levels of IL-6 and TNF-α in cells culture supernatant (all p<0.05). However, A20 only partly inhibited CD40 expression. Our study indicated that A20 overexpression may depress the inflammatory response induced by LPS in cultured RPMCs through negatively regulated the relevant function of adaptors in LPS signaling pathway.

Gastrointestinal-related uremic toxins in peritoneal dialysis: a pilot study with a 5-year follow-up

BACKGROUND AND AIMS

P-cresyl sulfate (PCS) and indoxyl sulfate (IS) were not only novel but essential factors associated with cardiovascular disease and mortality in patients with chronic kidney disease and hemodialysis. However, little evidence exams the effect in peritoneal dialysis (PD) patients.

METHODS

This pilot study recruited 46 stable PD patients in a single medical center. Serum levels of IS, PCS and biochemistry were measured concurrently. Clinical outcomes including cardiovascular, all-cause mortality and PD failure event were recorded during a 5-year follow-up.

RESULTS

Serum levels of free and total PCS were lower in patients with residual renal function (11.67 ± 6.92, p = 0.014, 0.77 ± 0.48, p = 0.046, respectively). Multivariate Cox regression analysis showed age (HR: 1.07, p = 0.01), serum CO2 (HR: 0.67, p = 0.02) and total PCS (HR: 1.05, p <0.01) were independently associated with cardiovascular events; only free PCS (HR: 1.42, p <0.01) reached significant correlation with all-cause mortality. Total IS (HR: 1.27, p = 0.03) significantly correlated with PD failure event after adjusting other confounding factors. Kaplan-Meier analysis revealed that patients with higher total and free PCS levels had higher cardiovascular events (log rank p <0.01, log rank p = 0.05, respectively) and mortality event (log rank p = 0.02, log rank p = 0.03, respectively) than those with lower levels. In addition, total IS (log rank p = 0.04), total PCS (log rank p = 0.01) and free PCS (log rank p <0.01) could independently predict PD failure event during the study period.

CONCLUSIONS

Our findings suggest PCS and IS may be a valuable surrogate in predicting poor clinical outcomes in PD patients.

Amelioration of ischemic brain damage by peritoneal dialysis

Ischemic stroke is a devastating condition, for which there is still no effective therapy. Acute ischemic stroke is associated with high concentrations of glutamate in the blood and interstitial brain fluid. The inability of the tissue to retain glutamate within the cells of the brain ultimately provokes neuronal death. Increased concentrations of interstitial glutamate exert further excitotoxic effects on healthy tissue surrounding the infarct zone. We developed a strategy based on peritoneal dialysis to reduce blood glutamate levels, thereby accelerating brain-to-blood glutamate clearance. In a rat model of stroke, this simple procedure reduced the transient increase in glutamate, consequently decreasing the size of the infarct area. Functional magnetic resonance imaging demonstrated that the rescued brain tissue remained functional. Moreover, in patients with kidney failure, peritoneal dialysis significantly decreased glutamate concentrations. Our results suggest that peritoneal dialysis may represent a simple and effective intervention for human stroke patients.

Perspectives of patients, families, and health care professionals on decision-making about dialysis modality--the good, the bad, and the misunderstandings!

OBJECTIVES

This study explored the factors influencing decision-making about dialysis modality, integrating the perspectives of patients, their families, and health care professionals within an Asian population. The study further sought to understand the low penetration rate of peritoneal dialysis (PD) in Singapore. ♢

METHODS

A sample of 59 participants comprising pre-dialysis patients, dialysis patients, caregivers, and health care professionals (HCPs) participated in semi-structured interviews to explore the decision-making process and their views about various dialysis modalities. Data were thematically analyzed using NVivo9 (QSR International, Doncaster, Australia) to explore barriers to and facilitators of various dialysis modalities and decisional support needs. ♢

RESULTS

Fear of infection, daily commitment to PD, and misperceptions of PD emerged as barriers to PD. Side effects, distance to dialysis centers, and fear of needling and pain were barriers to hemodialysis (HD). The experiences of other patients, communicated informally or opportunistically, influenced the preferences and choices of patients and family members for a dialysis modality. Patients and families value input from HCPs and yet express strong needs to discuss subjective experiences of life on dialysis (PD or HD) with other patients before making a decision about dialysis modality. ♢

CONCLUSIONS

Pre-dialysis education should expand its focus on the family as the unit of care and should provide opportunities for interaction with dialysis patients and for peer-led learning. Barriers to PD, especially misperceptions and misunderstandings, can be targeted to improve PD uptake.

Long-term efficacy of intermittent peritoneal dialysis using various doses

The objective of the present study was to investigate the long-term clinical efficacy of intermittent peritoneal dialysis (IPD) using various doses and to explore the most suitable dialysis dose and practice pattern for patients. A total of 52 inpatients/outpatients who had undergone IPD for more than 5 years were recruited and divided into three groups according to the dialysis dose: 4 liters in Group A, 6 liters in Group B and 8 liters in Group C. The dwell time was 4 h. All patients were fasted overnight. The dialysis adequacy, nutritional status, complication control, blood pressure and intra-abdominal infection were determined and observed among these patients. Barthel index (BI) and Hamilton Depression Scale (HAMD) were employed to measure the activities of daily living (ADL) and degree of depression, respectively. The dialysis adequacy and ultrafiltration volume in Group A were lower than those in Groups B and C, but the residual urine volume was larger than that in the latter two groups. In addition, there was a marked difference in the control of complications between Group A and Groups B and C. When compared to Groups A and B, the nutritional status in Group C was significantly decreased, the mean arterial pressure and intra-abdominal infection rates were dramatically increased, and the HAMD scores were also higher (P<0.05). No significant difference was noted in the BI. For patients undergoing long-term IPD, individualized dialysis dose may benefit the dialysis adequacy, nutritional status, control of complications, blood pressure, rate of intra-abdominal infection, ADL and depression.

A crosstalk between the Smad and JNK signaling in the TGF-β-induced epithelial-mesenchymal transition in rat peritoneal mesothelial cells

Transforming growth factor β (TGF-β) induces the process of epithelial-mesenchymal transition (EMT) through the Smad and JNK signaling. However, it is unclear how these pathways interact in the TGF-β1-induced EMT in rat peritoneal mesothelial cells (RPMCs). Here, we show that inhibition of JNK activation by introducing the dominant-negative JNK1 gene attenuates the TGF-β1-down-regulated E-cadherin expression, and TGF-β1-up-regulated α-SMA, Collagen I, and PAI-1 expression, leading to the inhibition of EMT in primarily cultured RPMCs. Furthermore, TGF-β1 induces a bimodal JNK activation with peaks at 10 minutes and 12 hours post treatment in RPMCs. In addition, the inhibition of Smad3 activation by introducing a Smad3 mutant mitigates the TGF-β1-induced second wave, but not the first wave, of JNK1 activation in RPMCs. Moreover, the inhibition of JNK1 activation prevents the TGF-β1-induced Smad3 activation and nuclear translocation, and inhibition of the TGF-β1-induced second wave of JNK activation greatly reduced TGF-β1-induced EMT in RPMCs. These data indicate a crosstalk between the JNK1 and Samd3 pathways during the TGF-β1-induced EMT and fibrotic process in RPMCs. Therefore, our findings may provide new insights into understanding the regulation of the TGF-β1-related JNK and Smad signaling in the development of fibrosis.

Association of metabolic changes with mortality of patients treated by peritoneal dialysis or hemodialysis

AIM

The aim of this study was to determine the survival of patients treated by peritoneal dialysis (PD) and hemodialysis (HD) and to detect any association with the type of metabolic changes.

METHODS

The outcome of clinical treatment of 407 dialysis patients was analyzed over a 4-year period. This included the demographic characteristics, the duration of dialysis, smoking, residual renal function, existence of metabolic syndrome and malnutrition, waist girth, body mass index (BMI), comorbidity, and routine biochemical parameters.

RESULTS

The overall mortality of the treated patients during the 4-year period was 53%, 37% for HD patients and 65% for PD patients. Metabolic syndrome was the dominant metabolic disorder affecting more than half of the HD patients, as well as being a predictive mortality parameter (beta = 0.560; p = 0.045). The PD-treated patients had an equal prevalence of metabolic syndrome and malnutrition, whereas statistically significant predictors of mortality outcome were BMI (beta = 0.088; p = 0.002) and waist girth (beta = 0.023; p = 0.031). The median survival value was significantly higher for HD patients [108 months; 95% confidence interval (CI) 65-151]. Residual renal function in PD patients was significantly related to mortality (p = 0.045).

CONCLUSION

Metabolic syndrome is a predictive parameter of mortality for HD patients, whereas for PD patients it is the waist girth and BMI. Preserved residual renal function in patients on PD is an important factor in reducing mortality.

[Peritoneal dialysis: a satisfactory experience of a misknown technique in Rabat University Hospital]

Peritoneal dialysis (PD) is a renal replacement therapy method that could be proposed in the first intention for the treatment of end stage renal disease (ESRD). The aim of the study is to describe the beginning and development of PD in "Ibn Sina" University Hospital in Rabat, and to evaluate the outcome of the patients treated by this technique.

PATIENTS AND METHODS

It is a descriptive study between July 2006 and December 2009, including 41 ESRD patients treated by PD. PD parameters as well as clinical and biological data were collected and analyzed.

RESULTS

The average age of our patients was 45.8±17.4-year-old. The sex-ratio (M/F) was 1.9. Professionally active patients (50%) as well as students (14) kept their activity throughout the study. Initially, 68.2% of the patients had hypertension whereas, at the end of the study, only 25.8% still suffered from hypertension. A better quality of dialysis as well as the conservation of a residual renal function were ensured in PD with 92.6% of the patients having a residual clearance higher than 2 mL/min. A correction of anemia was noted with higher rates of hemoglobin after the beginning of the treatment by peritoneal dialysis. None of our cases presented a denutrition and all our diabetic patients did not worsen with the exchanges in PD.

DISCUSSION AND CONCLUSION

PD has recently been introduced in Morocco. It must be encouraged and sustained. In our study, we noted a good quality of dialysis and a conservation of the residual renal function. These results should encourage the promotion of this technique, especially that there is an inequality of distribution of hemodialysis centers in Morocco and the inability to deal with all ESRD patients. Furthermore, renal transplantation is not always possible in our country. For that, a specific program of information of both generalists and specialists, especially nephrologists must be established.

Glucose-based peritoneal dialysis fluids downregulate toll-like receptors and trigger hyporesponsiveness to pathogen-associated molecular patterns in human peritoneal mesothelial cells

The objective of this study was to investigate the effects of glucose-based peritoneal dialysis (PD) fluids and icodextrin-based PD fluids on the expression of Toll-like receptor 2 (TLR2)/TLR4 and subsequent ligand-induced mitogen-activated protein kinase (MAPK) and NF-kappaB signaling and tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta) mRNA expression in human peritoneal mesothelial cells (HPMCs). A human peritoneal mesothelial cell line (HMrSV5) was stimulated with glucose-based and icodextrin-based peritoneal dialysis fluids. Cell viability was assessed using MTT [3-(4,5-dimethylthiazolyl)-2,5-diphenyl-2H-tetrazolium bromide]. TLR2/TLR4 expression was determined by real-time PCR, Western blotting, and an immunofluorescence assay. In addition, cells were pretreated with different PD solutions and then incubated with Pam3CSK4 or lipopolysaccharide (LPS), and the degrees of MAPK and NF-kappaB activation were reflected by detecting the phosphorylation levels of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), p38, and p65, using a Western blot method. TNF-alpha and IL-1beta mRNA expression was measured by real-time PCR. Glucose-based peritoneal dialysis fluids suppressed the expression of TLR2 and TLR4 proteins in HPMCs. Challenge of cells with either Pam3CSK4 or LPS resulted in impaired TNF-alpha and IL-1beta production. Moreover, reduced TLR2 and TLR4 levels in glucose-based peritoneal dialysis solution-treated mesothelial cells were accompanied by reduced p42/44 (ERK1/2), JNK, p38 MAPK, and NF-kappaB p65 phosphorylation upon TLR ligand engagement. No significant changes in MAPK and NF-kappaB signaling and TNF-alpha and IL-1beta mRNA expression were observed in icodextrin-based PD solution-treated mesothelial cells. Glucose-based PD solution, but not icodextrin-based PD solution, downregulates expression of TLR2/TLR4 by human peritoneal mesothelial cells and triggers hyporesponsiveness to pathogen-associated molecular patterns.

Peritoneal dialysis-associated peritonitis: clinical features and predictors of outcome

OBJECTIVES

The objective of this study was to identify the epidemiological, clinical, and microbiological factors affecting the outcome of peritoneal dialysis (PD)-associated peritonitis.

METHODS

All patients with PD-associated peritonitis, cared for at the University Hospital of Heraklion from 1990 to 2007, were retrospectively studied.

RESULTS

A total of 247 episodes of PD-associated peritonitis occurring in 82 patients were evaluated. The median age of patients was 68 years (range 10-92 years); 51 (62%) were males. There were 104 episodes (42%) of Gram-positive peritonitis, 46 (19%) of Gram-negative peritonitis, 13 (5%) of polymicrobial peritonitis, and 11 (4%) of fungal peritonitis. There were 64 (26%) complicated episodes. The latter included 22 (8.9%) relapses, 13 (5.3%) repeated episodes, 18 (7.3%) catheter removals, and 11 (4.5%) deaths. In multivariate analysis, the presence of a purulent exit-site infection (p<0.001), peritoneal dialysis effluent cell count >100 x 10(6)/l for more than 5 days (p<0.001), use of antimicrobials during the preceding 3 months (p<0.05), and low serum total protein level on admission (p<0.05) were independent predictors of a complicated course.

CONCLUSIONS

Exit-site infection, more than 5 days with a peritoneal dialysis effluent cell count >100 x 10(6)/l, prior use of antimicrobials, and low serum total protein level are potential predictors of complicated PD-associated peritonitis and may distinguish high-risk cases.

Nitric oxide synthase isoforms play distinct roles during acute peritonitis

Background. Acute peritonitis is the most frequent complication of peritoneal dialysis (PD). Increased nitric oxide (NO) release by NO synthase (NOS) isoforms has been implicated in acute peritonitis, but the role played by the NOS isoforms expressed in the peritoneum is unknown.

Methods. We investigated the structural and functional consequences of acute peritonitis induced by LPS in wild-type (WT) mice versus knockout mice (KO) for the endothelial NOS (eNOS), the inducible NOS (iNOS) or the neuronal NOS (nNOS).

Results. The level of NO metabolites (NOx) in the dialysate was maximal 18 h after LPS injection. LPS induced a significant increase in the transport of small solutes and decreased ultrafiltration in WT mice. These changes, which occurred without vascular proliferation, were paralleled by the upregulation of nNOS and eNOS, and the induction of iNOS. The transport modifications induced by LPS were significantly reversed in eNOS KO mice, but not modified in mice lacking iNOS or nNOS. In contrast, the increase of dialysate NOx was abolished in iNOS KO mice and significantly reduced in eNOS KO mice, but left unchanged in mice lacking nNOS. Mice lacking iNOS also showed more severe inflammatory changes, and a trend towards increased mortality following LPS.

Conclusion. These data demonstrate specific roles for NOS isoforms in the peritoneal membrane and suggest that selective eNOS inhibition may improve peritoneal transport during acute peritonitis.

Acute effects of peritoneal dialysis solutions in the mesenteric microcirculation

Long-term peritoneal dialysis induces morphological changes that may lead to gradual functional impairment of the peritoneal membrane. These changes are characterized by progressive reduction in solute transport or ultrafiltration failure. The mechanism of the peritoneal response to dialysis fluids has not yet been fully elucidated. We used video-microscopy for in vivo evaluation of microhemodynamics and peritoneal microvascular inflammatory response, after a single intraperitoneal exposure of rats to commercial PD fluids: (1) glucose 1.5 % PD solution; (2) lactate buffered glucose 4.25% PD solution; (3) Icodextrin 7%; (4) bicarbonate buffered glucose 3.86% PD fluid; and 5) Hanks solution. Sham-control groups were not injected. A 5-h exposure of the peritoneal membrane to glucose 1.5% PD solution or to Hanks solution did not induce a significant change in leukocyte rolling and adhesion. In contrast, PD solutions containing glucose 4.25% or Icodextrin 7.5% caused a significant 2-3-fold increase in leukocyte rolling (P < 0.001) and adhesion (P < 0.001) and a significant increase in venular blood flow velocity (P < 0.01) and shear rates (P < 0.05 for glucose 4.25%, and P < 0.01 for Icodextrin). Exposure to glucose 3.86% bicarbonate buffered (Physioneal) solution was associated with the lowest values of leukocyte rolling and adhesion among the PD solutions and with extremely higher venular flow velocities and shear rates. A single exposure to conventional PD solutions with a high concentration of glucose (4.25%) or polyglucose (Icodextrin 7.5%) induces changes consistent with an early peritoneal inflammatory response that may be attenuated by the use of bicarbonate-based fluids.

Angiotensin II upregulates Toll-like receptor 4 and enhances lipopolysaccharide-induced CD40 expression in rat peritoneal mesothelial cells

OBJECTIVE

Activation of Toll-like receptor 4 (TLR4) in peritoneal mesothelial cells by endotoxin contributes to peritoneal inflammation and fibrosis. Here we investigated TLR4 expression induced by angiotensin II (Ang II) and functional consequences of nuclear factor-kappaB (NF-kappaB) activation and CD40 expression in rat peritoneal mesothelial cells (RPMCs).

METHODS

TLR4, CD40, tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6) were determined by reverse transcription polymerase chain reaction (RT-PCR) and TLR4, IkappaBalpha, phospho-IkappaBalpha, NF-kappaB p65, and phospho-NF-kappaB p65 were analyzed by Western blot. The intracellular distribution of NF-kappaB p65 was detected by immunofluorescence.

RESULTS

Treatment of RPMCs with Ang II resulted in an increase in the expression of TLR4 mRNA and protein levels. Preincubation of RPMCs with Ang II significantly increased lipopolysaccharide (LPS)-induced phospho-IkappaBalpha and phospho-NF-kappaB p65 protein (P < 0.05 vs. LPS alone) and CD40, TNF-alpha, and IL-6 mRNA levels (P < 0.05 vs. LPS alone). A significantly increased nuclear staining of NF-kappaB p65 in cells treated with Ang II plus LPS was also observed.

CONCLUSIONS

Ang II upregulates the expression of TLR4 by RPMCs, resulting in enhanced NF-kappaB signaling and induction of CD40, TNF-alpha, and IL-6 expression. Locally produced Ang II in the peritoneum may have an amplified role in LPS-induced peritoneal inflammation.

The Relationship of P1 and Lewis Antigens with Peritoneal Dialysis–Related Escherichia Coli Peritonitis

It has been known that the P1 and Lewis antigens on red blood cells (RBCs) affect the risk of Escherichia coli–related urinary tract infection. In the present study, we investigated the associations between those antigens and peritoneal dialysis (PD)–related peritonitis and E. coli peritonitis.

We recruited 155 patients (66 men, 89 women) who were under PD treatment in July 2005, checked the P1 and Lewis antigen status of their RBCs, reviewed their medical charts, and recorded the dates and the causative pathogens of peritonitis episodes. The relationships between peritonitis and the antigens were analyzed.

The mean age of these PD patients was 52.5 ± 14.9 years, and the mean PD duration was 39.8 ± 38.2 months. A total of 66 peritonitis episodes occurred (over 93.4 patient– months) in 41 patients, with 8 patients having more than 1 episode. In particular, E. coli peritonitis accounted for 16 of the 66 peritonitis episodes. We fitted two multiple Cox proportional hazards models (with the robust variance method) for predicting the hazard rates of peritonitis-free and E. coli peritonitis-free survival times to our right-censored data with recurrent events. We found that patients on PD treatment for less than 4 years with (A) lower serum albumin, (B) one or more previous peritonitis episodes, or (C) negative Lewis a and positive Lewis b antigens (secretor) would be at higher risk of peritonitis. And, conditioning on blood type, the PD patients with one or more previous peritonitis episodes and (A) positive P1 antigen, (B) negative Lewis a and positive Lewis b antigens (secretor), or (C) positive Lewis a and negative Lewis b antigens (non-secretor) would be at higher risk of E. coli peritonitis.

[Cost of dialysis in France]

The provision of care for patients with end-stage chronic renal failure is an important medical and economic challenge for the Health Insurance. Previous studies have shown a lower cost for home dialysis. More recently, studies have confirmed identical short-term survival rates between haemodialysis and peritoneal dialysis. Notwithstanding, home dialysis techniques utilization remains weak in France. This work aims at: determining the average annual cost of dialysis, per patient and per technique of dialysis, and assessing the global annual cost of dialysis in France, from the Health Insurance perspective. Methodologically, this article provides a static estimation of the cost of dialysis. Costs related to co-morbidities of end-stage chronic renal failure have not been considered. Standard patient care schemes have been outlined by a multidisciplinary expert committee, for each dialysis technique, and have been valorised using publicly available data and tariffs recorded in 2005. Our result show that home dialysis techniques are the less costly, with an average annual cost per patient of 49.9, 49.7 and 50.0 k euro respectively for home haemodialysis, automated peritoneal dialysis, and continuous ambulatory peritoneal dialysis. Autodialysis, autonomous in-center haemodialysis and in-center haemodialysis respectively cost 59.5, 62.3 and 81.5 k euro per patient and per annum. The total 2005 cost of dialysis for the Health Insurance is estimated at 2.1 billion euro. Therefore, the development of alternative techniques to in-center haemodialysis, such as home dialysis or autonomous in-center haemodialysis, autodialysis being already well developed, could generate savings for the Health Insurance. From the patient's perspective, it could also allow the enlightened choice of the best customized technique, less guided by local offer than by medical or social criteria, as well as by the patient's own opinion.

Chronic systemic inflammation in dialysis patients: an update on causes and consequences

Despite marked improvements in dialysis technology during the last 20 years, the age-adjusted mortality rate in end-stage renal disease (ESRD) patients treated by dialysis is still unacceptably high and comparable to that of many cancer patients with metastases. The main cause of the increased mortality in ESRD patients is cardiovascular disease (CVD), which is twice as common and advances at twice the rate already in patients with early stages of chronic kidney disease as compared to the general population. Although traditional risk factors for CVD are common in dialysis patients, they can only in part explain the very high prevalence of CVD in this patient group. Recent evidence demonstrates that chronic inflammation, a non-traditional risk factor which is a commonly observed in dialysis patients, may cause progressive atherosclerotic CVD and malnutrition, itself an important risk factor for the development of CVD, by several pathogenetic mechanisms. The causes of inflammation in dialysis are multifactorial and include both dialysis-related and unrelated factors. While the long-term effects of chronic inflammation may be most important in the pathogenesis of CVD, the acute-phase reaction may also cause vascular damage by several pathogenic mechanisms. Indeed, it seems logical to speculate that suppression of the vicious cycle of malnutrition, inflammation, and atherosclerosis (MIA syndrome) in ESRD would improve survival and decrease co-morbidity in dialysis patients. As there are currently no established guidelines for the treatment of chronic inflammation in ESRD patients, more studies on the long-term effects of various anti-inflammatory treatment strategies on the nutritional and cardiovascular status, as well as outcome in this patient group, are clearly warranted and will be helpful in identifying precisely which pathways are most involved in the pathogenic process.

Peritoneal dialysis-associated peritonitis in Scotland (1999-2002)

BACKGROUND

Peritonitis is a major complication of peritoneal dialysis (PD). We have performed a national study of all patients on PD in Scotland over a 3.5 year period examining the causes of technique failure, rates of peritonitis, causative organisms, clinical outcomes and differences between automated peritoneal dialysis (APD) and continuous ambulatory peritoneal dialysis (CAPD).

METHODS

All 10 adult renal units in Scotland participated in the study and the data include all 1205 patients who were on PD in Scotland from January 1999 to June 2002. The data were collected prospectively by the PD nurses and reported to the Scottish Renal Registry every 6 months.

RESULTS

Refractory or recurrent peritonitis was the cause of technique failure in 167 patients (42.6% of all cases of technique failure). There were 928 cases of peritonitis in 1487 patient-years, which equates to an overall peritonitis rate of one episode every 19.2 months. The peritonitis rates for APD and CAPD were similar at one episode every 20.3 months and one episode every 18.6 months, respectively. These results include 88 cases of peritonitis due to relapse or re-infection. There was a statistically significant difference (P = 0.012) in peritonitis rates between units using nasal mupiricin (one episode every 21.9 months) and those that did not (one episode every 18.3 months). Coagulase-negative Staphylococcus was the most common cause of peritonitis (29%), although this rate is lower than in historic studies. The overall initial cure rate was 75%. The initial cure rate for APD was 77.2% and for CAPD was 73.7%. No causative organism was isolated in 17% of cases.

CONCLUSION

PD-associated peritonitis is the leading cause of technique failure in Scotland. We validate previous studies showing a decrease in the proportion of peritonitis episodes that are caused by coagulase-negative staphylococci. APD peritonitis rates are not significantly better than CAPD peritonitis rates in Scotland, and the initial cure rates for APD and CAPD are similar.

Effects of an angiotensin II receptor blocker, valsartan, on residual renal function in patients on CAPD

BACKGROUND

Both residual renal function and blood pressure (BP) control contribute to patient survival in patients receiving continuous ambulatory peritoneal dialysis (CAPD). It is unknown whether antihypertensive drugs affect residual renal function in addition to BP reduction.

METHODS

We examined the effects of an angiotensin II receptor blocker, valsartan, on residual renal function and total clearance (renal and peritoneal) in 34 Japanese CAPD patients from 3 months to 2 years after the start of dialysis therapy. Patients were randomly assigned to valsartan (n = 18; age, 63.5 +/- 3.7 years; 11 men, 7 women) or a control group (n = 16; age, 63.5 +/- 3.3 years; 10 men, 6 women). Conventional antihypertensive treatment was continued in all patients to achieve the target BP in both groups of 130/80 mm Hg or less, measured at home.

RESULTS

BP reduction was similar in the valsartan and control groups. Valsartan significantly slowed the progressive decline in both residual renal function (3.2 +/- 0.3 to 4.3 +/- 0.7 mL/min/1.73 m2) and total clearance (42.1 +/- 3.2 to 48.3 +/- 4.8 L/wk/1.73 m2) by dialysis in CAPD patients compared with controls (5.9 +/- 0.5 to 2.8 +/- 0.4 mL/min/1.73 m2; 47.1 +/- 4.8 to 31.4 +/- 5.2 L/wk/1.73 m2).

CONCLUSION

This study shows that in patients with hypertension starting CAPD therapy, valsartan slows the decline in residual renal function and contributes to maintenance of weekly creatinine clearance and Kt/V (fraction per dialysis), which are the major factors contributing to the mortality and morbidity of CAPD patients. This effect appears to be mostly a result of maintaining residual renal function.

Mice that Lack Endothelial Nitric Oxide Synthase Are Protected against Functional and Structural Modifications Induced by Acute Peritonitis

ABSTRACT. Pharmacologic studies suggest that the release of nitric oxide (NO) by endothelial NO synthase (eNOS) contributes to functional alterations of the peritoneal membrane (PM) induced by acute peritonitis. In this study, peritoneal permeability parameters in a mouse model of peritoneal dialysis were characterized, and the effects of eNOS deletion on the PM structure and permeability at baseline and after catheter-induced bacterial peritonitis were examined. Exposure of C57BL/6 mice to standard dialysate yielded a transport of urea and glucose, a sodium sieving, and a net ultrafiltration that were remarkably similar to the values obtained in rats. In comparison with controls, mice with catheter-induced peritonitis were characterized by structural changes in the PM (mononuclear cells infiltrate, vascular proliferation), upregulation of endothelial and inducible NOS, increased permeability for urea and glucose, decreased ultrafiltration, and increased protein loss in the dialysate. Comparison of eNOS wild-type and knockout mice revealed that the permeability modifications and structural changes induced by acute peritonitis were significantly reversed in eNOS knockout mice, resulting in a net increase in ultrafiltration. In contrast, the deletion of eNOS in mouse peritoneum was not reflected by permeability modifications or structural changes at baseline. These results are the first to take advantage of a knockout mouse model to demonstrate directly the crucial importance of eNOS in the permeability and structural modifications caused by acute peritonitis. The characterization of this mouse model suggests that genetically modified mice represent useful tools to investigate the molecular bases of the peritoneal changes during peritoneal dialysis.

Impact of dialysis modality on survival of new ESRD patients with congestive heart failure in the United States

BACKGROUND

It is hypothesized, but not proven, that peritoneal dialysis might be the optimal treatment for end-stage renal disease (ESRD) patients with established congestive heart failure (CHF) through better volume regulation compared with hemodialysis.

METHODS

National incidence data on 107,922 new ESRD patients from the Center for Medicare and Medicaid Services (CMS) Medical Evidence Form were used to test the hypothesis that peritoneal dialysis was superior to hemodialysis in prolonging survival of patients with CHF. Nonproportional Cox regression models evaluated the relative hazard of death for patients with and without CHF by dialysis modality using primarily the intent-to-treat but also the as-treated approach. Diabetics and nondiabetics were analyzed separately.

RESULTS

The overall prevalence of CHF was 33% at ESRD initiation. There were 27,149 deaths (25.2%), 5423 transplants (5%), and 3753 (3.5%) patients lost to follow-up over 2 years. Adjusted mortality risks were significantly higher for patients with CHF treated with peritoneal dialysis than hemodialysis [diabetics, relative risk (RR) = 1.30, 95% confidence interval (CI) 1.20 to 1.41; nondiabetics, RR = 1.24, 95% CI 1.14 to 1.35]. Among patients without CHF, adjusted mortality risk were higher only for diabetic patients treated with peritoneal dialysis compared with hemodialysis (RR = 1.11, 95% CI 1.02 to 1.21) while nondiabetics had similar survival on peritoneal dialysis or hemodialysis (RR = 0.97, 95% CI 0.91 to 1.04).

CONCLUSION

New ESRD patients with a clinical history of CHF experienced poorer survival when treated with peritoneal dialysis compared with hemodialysis. These data suggest that peritoneal dialysis may not be the optimal choice for new ESRD patients with CHF perhaps through impaired volume regulation and worsening cardiomyopathy.

Treatment of peritonitis in APD: pharmacokinetic principles

Clinicians treating peritoneal dialysis (PD)-associated peritonitis should be aware that continuous ambulatory PD (CAPD) and automated PD (APD) have different effects on the pharmacokinetics of antibiotics. Results from various APD and comparative CAPD pharmacokinetic studies are reviewed. In APD patients, antibiotic half-lives were shorter during the cycler exchanges. Antibiotic peritoneal clearance was greater in patients treated with APD than those treated with CAPD regimens. Antibiotic clearance depends upon residual renal function and dialysate flow rate. To ensure that maximal antibiotic bioavailability occurs with intermittent intraperitoneal (IP) dosing, it is recommended that the antibiotic-containing dialysate must dwell at least 4 hours to ensure an adequate antibiotic depot in the body. Knowledge of antibiotic disposition in PD patients will assist clinicians in appropriate IP antibiotic dose selection and prevention of dose-related adverse effects.

Relapsing culture-negative peritonitis in peritoneal dialysis patients exposed to icodextrin solution

BACKGROUND

Icodextrin is a new peritoneal dialysis fluid, with maltose polymers providing the osmotic drive, that may extend time on peritoneal dialysis in situations in which use of conventional glucose-based peritoneal dialysis fluid (Dianeal) has led to loss of ultrafiltration. Although cutaneous reactions have been reported, we report a new phenomenon of aseptic peritonitis that has arisen in our unit associated with icodextrin use.

METHODS

Icodextrin was first introduced in our unit in 1997 and was used extensively beginning in late 1999. From a combination of an observational study of 141 patients in our unit in whom icodextrin was used over 3.5 years and our unit 2000 and 2001 peritonitis audits, we identified an increase in the incidence of culture-negative peritonitis (CNP).

RESULTS

The rate in 2000 of 12.3% rose to 17% in 2001, but this increase was seen only in patients on icodextrin (Percentage changes 2000 audit > 2001 audit: icodextrin patients, 14%--31% increase; Dianeal alone, 12%--10% increase; P < 0.05). Six patients were affected in the period 2000 to 2001 out of a total of 141 patients exposed to icodextrin (4.3%). Two index cases of relapsing CNP responded after withdrawal of the icodextrin. We then adopted a protocol of cessation and rechallenge with icodextrin when dealing with CNP, which successfully confirmed the phenomenon and led to resolution of relapsing CNP after icodextrin withdrawal. All these patients had been on icodextrin for some time, and none had had an immediate reaction or any skin reaction. Eosinophils were reported in the peritoneal effluent from two patients. All patients continued Dianeal without further CNP episodes.

CONCLUSION

Icodextrin use carries the risk of CNP, and we suggest a cessation and rechallenge protocol in all patients on icodextrin who have CNP.

What's new in peritoneal dialysis: biocompatibility and continuous flow peritoneal dialysis

PURPOSE OF REVIEW

This review examines recent developments in the understanding of the effect of conventional, bioincompatible peritoneal dialysis fluids on structural and functional changes in the peritoneal membrane. Emphasis is placed on the clinically relevant outcome of failure of long-term peritoneal dialysis. Therapeutic strategies to prevent technique failure, including the use of new peritoneal dialysis fluids and continuous flow peritoneal dialysis, are explored.

RECENT FINDINGS

Long-term (greater than 6 months) exposure to new peritoneal dialysis fluids with physiologic pH, lower lactate concentrations, or lower concentrations of glucose degradation products results in improved leukocyte cytokine release, ultrafiltration, and mesothelial cell mass, respectively. Continuous flow peritoneal dialysis allows efficient small molecule removal using dialysate with lower glucose concentration and possibly less glucose degradation products. Recent technical advances include creation of a double-lumen peritoneal dialysis catheter, and methods of monitoring intra-abdominal pressure and ultrafiltration.

SUMMARY

Though initial reports with biocompatible peritoneal dialysis fluids are promising, the efficacy of these new solutions in preventing long-term peritoneal dialysis failure is unproven. Conditions in which new peritoneal dialysis fluids may be beneficial are suggested. Continuous flow peritoneal dialysis requires substantial technical improvements before this technique can be widely accepted.