How has peritoneal dialysis changed over the last 30 years: experience of the Verona dialysis center

Impact of the Type of Dialysis on Time to Transplantation: Is It Just a Matter of Immunity?

Background: Renal transplantation represents the therapeutic gold standard in patients with end stage renal disease (ESRD). Still the role of pre-transplant dialysis in affecting time to transplantation has yet to be determined. We wanted to verify whether the type of renal replacement therapy (hemodialysis vs. peritoneal dialysis) affects time to transplantation and to identify clinical features related to the longer time to transplantation. Methods: We performed a retrospective single-center observational study on patients who had received a transplant in the Bologna Transplant Unit from 1991 to 2019, described through the analysis of digital transplant list documents for sex, age, body mass index (BMI), blood group, comorbidities, underlying disease, serology, type of dialysis, time to transplantation, Panel Reactive Antibodies (PRA) max, number of preformed anti Human Leukocyte Antigens (HLA) antibodies. A p-value < 0.05 was considered statistically significant. Results: In the 1619 patients analyzed, we observed a significant difference in time to transplant, PRA max and Preformed Antibodies Number between patients who received Hemodialysis (HD) and Peritoneal dialysis (PD). Then we performed a multiple regression analysis with all the considered factors in order to identify features that support these differences. The clinical variables that independently and directly correlate with longer time to transplantation are PRA max (p < 0.0001), Antibodies number (p < 0.0001) and HD (p < 0.0001); though AB blood group (p < 0.0001), age (p < 0.003) and PD (p < 0.0001) inversely correlate with time to transplantation. Conclusions: In our work, PD population received renal transplants in a shorter period of time compared to HD and turned out to be less immunized. Considering immunization, the type of dialysis impacts both on PRA max and on anti HLA antibodies.

Shared Decision-Making for a Dialysis Modality

The prevalence of kidney failure continues to rise globally. Dialysis is a treatment option for individuals with kidney failure; after the decision to initiate dialysis has been made, it is critical to involve individuals in the decision on which dialysis modality to choose. This review, based on evidence arising from the literature, examines the role of shared decision-making (SDM) in helping those with kidney failure to select a dialysis modality. SDM was found to lead to more people with kidney failure feeling satisfied with their choice of dialysis modality. Individuals with kidney failure must be cognizant that SDM is an active and iterative process, and their participation is essential for success in empowering them to make decisions on dialysis modality. The educational components of SDM must be easy to understand, high quality, unbiased, up to date, and targeted to the linguistic, educational, and cultural needs of the individual. All individuals with kidney failure should be encouraged to participate in SDM and should be involved in the design and implementation of SDM approaches.

Smoking is a Risk Factor for Endogenous Peritonitis in Patients Undergoing Peritoneal Dialysis

BACKGROUND

Peritonitis is one of the most common complications in patients undergoing peritoneal dialysis, (PD) but it is difficult to predict or prevent. In this study, we analyzed the risk of endogenous peritonitis in patients receiving PD.

METHODS

We included all patients who underwent PD at our hospital from April 2015 to March 2020. There were 22 cases of peritonitis, including 18 cases of endogenous peritonitis without evidence of exit-site infection or technical failure. We evaluated older age, female sex, obesity, diabetes, diverticulosis, and constipation as potential important risk factors for endogenous peritonitis and included these as confounding factors, along with a current or previous history of smoking, in univariate logistic regression models.

RESULTS

A previous or current history of smoking (p = 0.0065) was the most significant risk factor for endogenous peritonitis in the univariate logistic regression model. In addition, smoking was the most significant independent risk factor for endogenous peritonitis (p = 0.0034) in multivariate logistic regression models. Diabetes was also significant in univariate and multivariate logistic regression analysis.

CONCLUSIONS

Smoking is a significant independent risk factor for endogenous peritonitis in patients undergoing PD. Cessation of smoking may lower the risk of endogenous peritonitis in this patient group.

Biological Effects of XyloCore, a Glucose Sparing PD Solution, on Mesothelial Cells: Focus on Mesothelial-Mesenchymal Transition, Inflammation and Angiogenesis

Glucose-based solutions remain the most used osmotic agents in peritoneal dialysis (PD), but unavoidably they contribute to the loss of peritoneal filtration capacity. Here, we evaluated at a molecular level the effects of XyloCore, a new PD solution with a low glucose content, in mesothelial and endothelial cells. Cell viability, integrity of mesothelial and endothelial cell membrane, activation of mesothelial and endothelial to mesenchymal transition programs, inflammation, and angiogenesis were evaluated by several techniques. Results showed that XyloCore preserves mesothelial and endothelial cell viability and membrane integrity. Moreover XyloCore, unlike glucose-based solutions, does not exert pro-fibrotic, -inflammatory, and -angiogenic effects. Overall, the in vitro evidence suggests that XyloCore could represent a potential biocompatible solution promising better outcomes in clinical practice.

Low serum albumin a predictor sign of the incidence of peritoneal dialysis-associated peritonitis? A quasi-systematic review

Peritonitis is associated with an increasing morbidity and mortality rate in peritoneal dialysis patients. A number of peritonitis cases result in hypoalbuminemia, and in other cases, peritonitis follows a decline in the serum albumin level. However, it is not clear whether the level of serum albumin can be utilized to predict and prevent the incidence of peritonitis. A quasi-systematic search of the literature was conducted in the following databases: Cochrane, EBSCO, ProQuest, AHMED, CINHAL, MEDLINE, and EMBASE, from January 2008 to January 2018. The data was reviewed and extracted from each study. The quality of the studies was assessed using the Critical Appraisal Skills Programme and the Newcastle-Ottawa Scale. Six articles met the stated inclusion criteria of the quasi-systematic review. The study found a significant correlation between a low serum albumin level at the start of continuous ambulatory peritoneal dialysis (CAPD) and the development of peritonitis. Thus, hypoalbuminemia can be utilized as a warning sign of the occurrence of peritonitis in CAPD. Consequently, immediate intervention is required when the level of serum albumin declines in order to prevent peritonitis.

Serum Chromium Levels Are Higher in Peritoneal Dialysis than in Hemodialysis Patients

Background:An elevation in serum chromium levels in individuals treated with renal replacement therapy has been previously described, but chromium levels have not been systematically studied in patients treated with different dialysis modalities. The aim of this study was to compare serum chromium levels in patients treated with chronic peritoneal dialysis (PD) and hemodialysis (HD).Methods:We studied 169 chronic dialysis patients in a single medical center, of which 148 were treated with HD and 21 with PD. Serum chromium levels were measured by atomic absorption spectrometry.Residual renal function was accessed using a timed urine collection for the measurement of urine output and calculation of glomerular filtration rate (GFR).Results:The median (interquartile range) serum chromium level was significantly higher in patients treated with PD than in patients treated with HD: 5.00 (3.24 - 6.15) vs 1.83 (1.29 - 2.45) mcg/L, p < 0.001. In a univariate analysis, serum chromium level was associated with PD modality: Exp (B) 7.46 (95% confidence interval [CI] 2.1 - 26.4), p = 0.002. The association of PD modality with serum chromium level was even more significant using a multivariate logistic regression model: odds ratio (OR) 11.87 (95% CI 2.85 - 49.52), p = 0.001 after adjustment for age, gender, diabetes, smoking, dialysis vintage, use of diuretics, and residual renal function.Conclusions:In patients treated with chronic dialysis, serum chromium levels are higher in patients treated with PD than in those treated with HD.

Clinical management of patients on peritoneal dialysis in Italy: results from the ATENA study

BACKGROUND

In Italy, few studies have examined the clinical management of peritoneal dialysis (PD) patients, resulting in a lack of information and awareness.

METHODS

A total of 378 PD patients (64.7 ± 14.3 years, 58.9% males) were enrolled across 15 centres in a 12-month retrospective and 6-month prospective study. The primary objective was to evaluate the achievement of Kidney Disease Outcomes Quality Initiative and Kidney Disease Improving Global Outcomes guidelines on recommended target values for anaemia, high blood pressure and mineral metabolism. Comorbidities, hospitalizations, treatment and quality of life were also assessed.

RESULTS

Frequent comorbidities included hypertension (87.8%) and cardiovascular disease (39.7%). Peritonitis was the leading cause of hospitalization [12 admissions per 100 person-years (95% confidence interval 9.3-15.2)]. At 6 months, anaemia corrected by erythropoiesis-stimulating agents was observed in 30% of patients and 73% received erythropoiesis-stimulating agents. Systolic and diastolic blood pressures were recorded in 50% and 20% of patients, respectively. Sixty-four percent of echocardiograms revealed left ventricular hypertrophy and 30% of patients had vitamin D <10 ng/mL. Medication to treat intact parathyroid hormone (PTH) included calcitriol (36.3%), paricalcitol (29.2%), cholecalciferol (23.6%) and cinacalcet (21.5%). In a subgroup of patients matched for baseline PTH treated for 1 year, a significant reduction in PTH with paricalcitol (-41%; P < 0.001) but not cinacalcet (+2%; P = 0.63) was observed. Comparison of quality of life domains revealed significant differences for symptoms (P = 0.049), cognitive function (P = 0.019) and social support (P = 0.04) (baseline versus 6 months).

CONCLUSIONS

Hypertension and cardiovascular diseases were frequent comorbidities and peritonitis was the leading cause of hospitalization. Secondary hyperparathyroidism and anaemia were common, thus necessitating frequent monitoring of PTH, calcium, phosphorus and haemoglobin.

Specific heparanase inhibition reverses glucose-induced mesothelial-to-mesenchymal transition

Background

Epithelial-to-mesenchymal transition (EMT) of peritoneal mesothelial cells induced by high glucose (HG) levels is a major biological mechanism leading to myofibroblast accumulation in the omentum of patients on peritoneal dialysis (PD). Heparanase (HPSE), an endoglycosidase that cleaves heparan sulfate chains, is involved in the EMT of several cell lines, and may have a major role in this pro-fibrotic process potentially responsible for the failure of dialysis. Its specific inhibition may therefore plausibly minimize this pathological condition.

Methods

An in vitro study employing several biomolecular strategies was conducted to assess the role of HPSE in the HG-induced mesothelial EMT process, and to measure the effects of its specific inhibition by SST0001, a N-acetylated glycol-split heparin with a strong anti-HPSE activity. Rat mesothelial cells were grown for 6 days in HG (200 mM) culture medium with or without SST0001. Then EMT markers (VIM, α-SMA, TGF-β) and vascular endothelial growth factor (VEGF) (a factor involved in neoangiogenesis) were measured by real-time PCR and immunofluorescence/western blotting. As a functional analysis, trans-epithelial resistance (TER) and permeability to albumin were also measured in our in vitro model using a Millicell-ERS ohmmeter and a spectrophotometer, respectively.

Results

Our results showed that 200 mM of glucose induced a significant gene and protein up-regulation of VEGF and all EMT markers after 6 days of culture. Intriguingly, adding SST0001 on day 3 reversed these biological and cellular effects. HPSE inhibition also restored the normal TER and permeability lost during the HG treatment.

Conclusion

Taken together, our data confirm that HG can induce EMT of mesothelial cells, and that HPSE plays a central part in this process. Our findings also suggest that pharmacological HPSE inhibition could prove a valuable therapeutic tool for minimizing fibrosis and avoiding a rapid decline in the efficacy of dialysis in patients on PD, though clinical studies and/or trials would be needed to confirm the clinical utility of this treatment.

A prime determinant in selecting dialysis modality: peritoneal dialysis patient survival

The number of patients with end-stage renal disease (ESRD) has rapidly increased, as has the cost of dialysis. Peritoneal dialysis (PD) is an established treatment for ESRD patients worldwide; it has a variety of advantages, including autonomy and flexibility, as well as economic benefits in many countries compared to hemodialysis (HD). However, the long-term survival rate of PD remains poor. Although direct comparison of survival rate between the dialysis modalities by randomized controlled trials is difficult due to the ethical issues, it has always been a crucial point when deciding which dialysis modality should be recommended to patients. Recently, in many countries, including the United States, Brazil, Spain, Australia, and New Zealand, the survival rate in PD patients has significantly improved. PD patient survival in Korea has also improved, but Korean PD patients are known to have higher risk of mortality and major adverse cardiovascular, cerebrovascular events than HD patients. Herein, we further evaluate why Korean PD patients had worse outcomes; we suggest that special attention should be paid to patients with diabetes, coronary artery disease, or congestive heart failure when they choose PD as the first dialysis modality in order to reduce mortality risk.

Survival and time-to-transplantation of peritoneal dialysis versus hemodialysis for end-stage renal disease patients: competing-risks regression model in a single Italian center experience

Aims

Despite several studies reporting similar outcomes for peritoneal dialysis (PD) and hemodialysis (HD), the former is underused worldwide, with a PD prevalence of 15% in Italy. In 2008, the Unit of Nephrology and Dialysis of the Healthcare Trust of the Autonomous Province of Trento implemented a successful PD program which has increased the proportion of PD incident patients from 7 to 47%. We aimed to assess the effect of this extensive use of PD by comparing HD and PD in terms of survival and time-to-transplantation.

Methods

A total of 334 HD and 153 PD incident patients were enrolled between January 2008 and December 2014. After screening for exclusion criteria and propensity score matching, 279 HD and 132 PD patients were analyzed. Survival and time-to-transplantation were assessed by competing-risks regression models, using death and transplantation as primary and competing events.

Results

Crude and adjusted regression models for survival revealed the absence of significant differences between HD and PD cumulative incidence functions (subhazard ratio: 1.09, p = 0.62 and 1.34, p = 0.10, respectively). Differently, crude and adjusted regression models for transplantation revealed a lower time-to-transplantation for PD versus HD patients (subhazard ratio: 2.34, p < 0.01, and 2.57, p < 0.01, respectively). The waiting time for placement in the transplant waiting list was longer in HD than PD patients (330 vs. 224 days, p < 0.01).

Conclusions

The extensive use of PD did not lead to any statistically significant difference in mortality. Furthermore, PD was associated with lower time to transplantation. PD may be a viable option for large-scale dialytic treatment in the advanced chronic kidney disease population.