Peritoneal Transport Characteristics Research Articles

#2055 Variations in free water transport condition ultrafiltration capacity since basal times

Abstract Background and Aims There is great variability in free water carrying capacity (FFWC) in incident patients, but the extent to which this variability impacts inherent ultrafiltration failure (UF) is unknown. The peritoneal equilibration test (PET) with 3.86% glucose allows measurement of permeability (D/Pcr), standard UF (UFs) and sodium screening (CriNa) as an indirect measure of TAL. Our objectives were to determine to what extent variations in free water transport condition a related ultrafiltration failure. To assess, according to the variables studied, whether or not the patient`s comorbidities or anthropometric data influenced our study. Method We conducted a study in 58 incident patients in our hospital between 2009-2023 in which we evaluated D/Pcr, UFs and CriNa in PET -3.86. We recorded the dialysis pattern and daily UF. Results The PET -3.86% results were evaluated (Table 1), showing the clinical and peritoneal transport characteristics of the total patients and the comparison between patients with CriNa lower or higher than the median. The patients with lower CriNa were older and had lower UFs and UFd. We found a correlation between CriNa and UFs (0.39, p = 0.002) and daily UF (0.318, p = 0.05). In the multiple regression analysis, CriNa and D/Pcr maintain the correlation with UFs independently. While only CriNa maintains the correlation with daily UF, despite there being no differences in the use of DPA or icodextrin. Conclusion On analyzing the results, we found that the intrinsic variations of the membrane, in the free water transport capacity, justify part of the ultrafiltration capacity measured both in kinetics and daily ultrafiltration. As for age, we found that the older the patient is, the lower the sodium sieving, at least initially. With this study we emphasize the importance of assessing variations in free water transport capacity using the peritoneal equilibrium test as a tool.

Association between protein energy wasting and peritoneal membrane transport in peritoneal dialysis.

fast peritoneal transport (FT) has been associated with peritoneal albumin loss and protein energy wasting (PEW); however, this relationship has not been fully studied. the aim of this study was to analyze the differences in nutritional parameters between fast-transport peritoneal membrane (FT-PET) and slow-transport peritoneal membrane (ST-PET), and analyze the association between FT-PET and PEW in peritoneal dialysis (PD) patients. a cross-sectional study of patients on PD. Peritoneal transport characteristics were assessed using the peritoneal equilibration test (PET). Malnutrition inflammation score (MIS) was used for PEW identification. Clinical and biochemical characteristics between patients with and without PEW were assessed. Association between FT-PET status and PEW were evaluated using univariate and multivariate logistic regression. a total of 143 patients were included. FT-PET group showed a higher prevalence of hypoalbuminemia, edema, lower phase angle, lower energy intake, and higher values of MIS score. FT-PET was significantly associated with PEW on univariate (OR: 3.5, 95 % CI: 1.56-7.83, p = 0.002) and multivariate models (OR: 2.6, 95 % CI: 1.02-6.6, p = 0.04). This association was maintained in patients where baseline PET was performed after initiating PD therapy (OR: 6.2, 95 % CI: 1.01-38.6, p = 0.04). FT-PET is associated with PEW evaluated by MIS score. Clinical trials to study nutritional interventions personalized to peritoneal-membrane transport characteristics should be designed.

Influence of peritoneal residual volume on the results of the peritoneal equilibration test. Prospective study

BackgroundCategorization of the capacity of ultrafiltration during a peritoneal equilibration test (PET) is a usual step during the monitoring of peritoneal transport characteristics of Peritoneal Dialysis (PD) patients. Quantifying the peritoneal residual volume (Vr) after the dwell preceding the PET (Vrpre) and at the end of the test (Vrpost) could help to improve the accuracy of the estimation of this variable. MethodFollowing a prospective design, we calculated Vrpre and Vrpost in 116 patients, incident or prevalent on DP, who underwent one or two (n = 27) PET with 3,86/4,25% glucose-based PD solutions and complete drainage at 60 min. We evaluated the consistency of Vr by comparing Vrpre and Vrpost, as also these two parameters in repeated tests. We scrutinized potential associations between demographic and clinical factors, on one side, and the amount of Vr on the other, as also the impact of correcting ultrafiltration during PET for Vr on the categorization of the capacity of ultrafiltration. ResultsAs a mean, Vrpost was larger than Vrpre. Consequently, correction of ultrafiltration for Vr resulted in significantly higher values than those obtained according to the standard procedure (494 vs. 449 mL, p < 0,0005). We disclosed marked inconsistencies for different estimations of Vr in the same patients (Vrpre vs Vrpost and repeated PET studies). Moreover, no demographic or clinical variable was able to predict the amount of Vr. We observed a significant deviation (>200 mL) between both methods of estimation of the capacity of utrafiltration in only 12,9% of the patients. However, 21,1% of the patients categorized as cases of ultrafiltration failure according to the standard procedure did not maintain this condition after correction for Vr. ConclusionsCorrection for Vr of the capacity of ultrafiltration during a PET carries, as a mean, a minor impact on the categorization of this parameter. However, the results of the test can be significantly affected in 12,9% of the cases. We have been unable to detect demographic or clinical predictors of Vr, which suggests a random component for the mechanics of single peritoneal exchanges. We suggest that Vr should be estimated at the time of categorizing the capacity of ultrafiltration, whenever inconsistencies during serial PET studies are detected.

Prescribing and peritoneal dialysis.

Peritoneal dialysis is a home-based therapy for patients with end-stage kidney disease. It is less efficient in removing solutes and fluid than haemodialysis but offers more flexibility and independence. Peritoneal transport characteristics affect the dialysis prescription. The timing of drug administration is independent of the dialysis process except for the administration of intraperitoneal antibiotics. Dose reductions should follow current recommendations for patients with kidney disease. Fluid overload is common in patients undergoing peritoneal dialysis. Residual kidney function can ameliorate this problem and needs to be preserved. Dialysis solutions with high glucose concentrations contribute to adverse metabolic effects. Peritoneal dialysis-related catheter complications and infections may require patients to transition to haemodialysis. Antifungal prophylaxis needs to be co-administered for the duration of antibiotic courses for any indication to reduce the risk of fungal peritonitis. Close communication with the patient's supervising dialysis unit is required.

MO683: Peritoneal Transport Characteristics, Sodium Sieving and Dialysate Electrolyte Clearance in Peritoneal Dialysis Patients: 4.25% Peritoneal Equilibration Test Analysis

Abstract BACKGROUND AND AIMS Peritoneal dialysis (PD) is a well-established renal replacement therapy for patients with end-stage renal disease. The peritoneal equilibration test (PET) is widely used for assessing peritoneal solute transport. Recently, the International Society for PD committee recommended performing PET with 4.25% dextrose solution instead of traditional 2.5% dextrose solution to provide better information on ultrafiltration capacity. This study aims to explore the peritoneal transport characteristics, sodium sieving and electrolyte clearance with PET-4.25%. METHOD We conducted a cross-sectional study in PD patients treated in West China Hospital between June 2021 and December 2021. All patients underwent PET-4.25%. Peritoneal transport characteristics, sodium sieving and dialysate electrolyte clearance were analysed. RESULTS A total of 108 patients (61 males, 56%; mean age 48 ± 4 years old, median PD duration 17 months) were included. Dialysate to plasma (D/P) creatinine values at 4 h were distributed similarly in PET-2.5% and PET-4.25% (Fig. 1). The dialysate sodium decreased at the beginning of PET-4.25% and gradually increased, while other dialysate electrolyte levels continued to increase or decrease during the 4 h (Fig. 2). Most patients had their maximal sodium dip at 2 h (N = 80, 74%). The mean sodium dip at 1 h was 7.28 ± 2.93 mmol/L (sodium sieving ratio 0.057 ± 0.023), and the mean maximal sodium dip was 8.81 ± 4.18 mmol/L. In both univariate and multivariate analyses, sodium sieving was negatively correlated with 4-h D/P creatinine and glomerular filtration rate (GFR) and positively correlated with PET-4.25% ultrafiltration volume (Fig. 3). The total clearances of sodium, potassium, chloride, calcium, magnesium and phosphate with 2 L of 4.25% dextrose were 66.9 ± 22.4 mmol, 6.64 ± 1.25 mmol, 62.7 ± 27.7 mmol, 0.07 ± 0.27 mmol, 0.63 ± 0.19 mmol and 1.98 ± 0.63 mmol, respectively. The amount of electrolyte clearance was not related to peritoneal transport characteristics. Nine patients were diagnosed with ultrafiltration failure (UFF). Patients with UFF had significantly lower sodium and chloride clearance than non-UFF patients. CONCLUSION PET-4.25% could assess peritoneal transport characteristics with similar results to PET-2.5%, while it could provide more information on ultrafiltration capacity. Four-hour D/P creatinine, GFR and ultrafiltration volume are independent predictors for sodium sieving. Dialysate electrolyte clearance is not related to peritoneal transport characteristics, while sodium clearance is decreased in UFF patients.

Baseline Peritoneal Membrane Transport Characteristics Are Associated with Peritonitis Risk in Incident Peritoneal Dialysis Patients.

The peritoneal equilibration test (PET) is a semi-quantitative measurement that characterizes the rate of transfer of solutes and the water transfer rate across the peritoneum in patients treated with peritoneal dialysis (PD). The results of the PET are used to maximize daily peritoneal ultrafiltration and solute clearances. Previous studies have shown that high transport status is associated with ultrafiltration failure, malnutrition, and reduced survival; however, the way in which peritoneum transport characteristics affect peritonitis risk is unknown. In the current cohort study, we recruited 898 incident-PD patients and used intention-to-treat analysis to test if baseline PET affected the subsequent 3-year peritonitis rate. Among all recruited PD patients, 308 (34.2%) developed peritonitis within three years. Multivariate Cox regression analysis showed that the high-transport group has the greatest peritonitis risk (HR 1.98, 95% CI: 1.08–3.62) even after an adjustment for demographics, comorbid diseases, and biochemical measurements. We concluded that a baseline high peritoneal membrane transport rate is an independent risk factor for peritonitis in incident PD patients.

Aquaporin-1 variants: a step further towards precise prescription in peritoneal dialysis?

With a concerted effort to increase home dialysis utilization, it is crucial to better understand patient characteristics that affect the quality of dialysis delivered, as well as the likelihood of technique failure. In peritoneal dialysis (PD), the quality of dialysis is dictated by the patient’s peritoneal membrane water and solute transport characteristics. Studies that shed light on determinants of peritoneal membrane function in an individual patient may assist providers in personalizing PD prescriptions.

Influencia del volumen peritoneal residual en los resultados de la prueba de equilibrio peritoneal. Estudio prospectivo

BackgroundCategorization of the capacity of ultrafiltration during a peritoneal equilibration test (PET) is a usual step during the monitoring of peritoneal transport characteristics of peritoneal dialysis (PD) patients. Quantifying the peritoneal residual volume (Vr) after the dwell preceding the PET (Vrpre) and at the end of the test (Vrpost) could help to improve the accuracy of the estimation of this variable. MethodFollowing a prospective design, we calculated Vrpre and Vrpost in 116 patients, incident or prevalent on DP, who underwent one or two (n=27) PET with 3.86/4.25% glucose-based PD solutions and complete drainage at 60min. We evaluated the consistency of Vr by comparing Vrpre and Vrpost, as also these two parameters in repeated tests. We scrutinized potential associations between demographic and clinical factors, on one side, and the amount of Vr on the other, as also the impact of correcting ultrafiltration during PET for Vr on the categorization of the capacity of ultrafiltration. ResultsAs a mean, Vrpost was larger than Vrpre. Consequently, correction of ultrafiltration for Vr resulted in significantly higher values than those obtained according to the standard procedure (494 vs 449mL, p<0.0005). We disclosed marked inconsistencies for different estimations of Vr in the same patients (Vrpre vs Vrpost and repeated PET studies). Moreover, no demographic or clinical variable was able to predict the amount of Vr. We observed a significant deviation (>200mL) between both methods of estimation of the capacity of utrafiltration in only 12.9% of the patients. However, 21.1% of the patients categorized as cases of ultrafiltration failure according to the standard procedure did not maintain this condition after correction for Vr. ConclusionsCorrection for Vr of the capacity of ultrafiltration during a PET carries, as a mean, a minor impact on the categorization of this parameter. However, the results of the test can be significantly affected in 12.9% of the cases. We have been unable to detect demographic or clinical predictors of Vr, which suggests a random component for the mechanics of single peritoneal exchanges. We suggest that Vr should be estimated at the time of categorizing the capacity of ultrafiltration, whenever inconsistencies during serial PET studies are detected.

The Effect of Far-Infrared Therapy on the Peritoneal Membrane Transport Characteristics of Uremic Patients Undergoing Peritoneal Dialysis: An Open-Prospective Proof-of-Concept Study.

Long-term peritoneal dialysis (PD) can lead to detrimental changes in peritoneal membrane function, which may be related to the accumulation of glucose degradation products. A previous study demonstrated that 6 months of far-infrared (FIR) therapy may decrease glucose degradation products in PD dialysate. Due to limited literature on this matter, this study aims to investigate the effect of FIR therapy on the peritoneal membrane transport characteristics of PD patients. Patients were grouped according to baseline peritoneal transport status: lower transporters (low and low-average) and higher transporters (high-average and high). Both groups underwent 40 min of FIR therapy twice daily for 1 year. In lower transporters, FIR therapy increased weekly dialysate creatinine clearance (6.91 L/wk/1.73 m2; p = 0.04) and D/P creatinine (0.05; p = 0.01). In higher transporters, FIR therapy decreased D/P creatinine (−0.05; p = 0.01) and increased D/D0 glucose (0.05; p = 0.006). Fifty percent of high transporter patients shifted to high-average status after FIR therapy. FIR therapy may decrease D/P creatinine for patients in the higher transporter group and cause high transporters to shift to high-average status, which suggests the potential of FIR therapy in improving peritoneal membrane function in PD patients.

MO710GALECTIN-3, IS IT A NEW PLAYER IN PERITONEAL INFLAMMATION AMONG PATIENTS UNDERGOING PERITONEAL DIALYSIS?

Abstract Background and Aims Peritoneal dialysis (PD) is a common used method for renal replacement therapy. Prolonged PD treatment causes structural and functional changes in the peritoneal membrane which are attributed to local inflammatory process in the peritoneal cavity. Galectin-3 (Gal-3) is a galactoside-binding lectin with pro-inflammatory and pro-fibrotic effects. The aim of this study was to assess correlation between Gal-3 serum and dialysate effluent levels with peritoneal membrane transport characteristics. Method Gal-3 levels in serum and dialysate effluent were measured simultaneously in prevalent PD patients in morning visit or during peritoneal equilibration test (PET). Gal-3 levels were correlated with clinical and laboratory parameters. Interlukin (IL) -6 levels were measured in dialysate effluent. Gal-3 mRNA and protein expression were evaluated after exposure of primary endothelial cell culture to several dialysate solutions. Results 37 PD patients were included in the study; mean age was 65.7±13.1 years, mean dialysis vintage was 17.5±13 months. Gal-3 levels in dialysate effluent correlated with peritoneal equilibration test (PET) results (0.663, p=0.005) and effluent IL-6 levels (0.674, p=0.002) but not with serum Gal-3 levels or dialysis vintage. Patients with high PET results had higher effluent Gal-3 levels as compared average low PET results. In multivariate regression analysis effluent IL-6 level was the most dominant predictor of effluent Gal-3 levels. Gal-3 mRNA and protein expression in primary endothelial cell culture were not affected by stimulation with dialysate solutions. Conclusion Our study demonstrated presence of Gal-3 within the dialysate effluent in PD patients. Gal-3 levels correlated with peritoneal membrane transport characteristics and effluent IL-6 levels suggesting a role in the inflammatory process within the peritoneal cavity.

MO699PERITONITIS RISK OF PD MODALITIES AND TECHNICAL SURVIVAL ACCORDING TO BASELINE PERITONEAL TRANSPORT STATUS

Abstract Background and Aims The PD modality is usually modulated according to the PET and dialysis adequacy during follow-up but, initial modality choice generally depends on patient preferences and lifestyle regardless of patients’ baseline transport status. However, the relationship between baseline transport status, the PD modality chosen, and technical survival is not well established. Peritonitis is one of the leading causes of technical failure, hospitalization, and death in PD. While obesity, low albumin levels, exit-site infections, and nasal staphylococcus carriage are well-defined risk factors for peritonitis, some suggest CAPD could be another risk factor due to increased daily connection to PD. Many studies indicated that CAPD and APD have similar technical survival rates. In this study, we aimed to identify the impact of the baseline transport status on technical survival of CAPD and APD. We also investigated peritonitis risk of modalities considering all defined risk factors. Method This is a retrospective, single-center, cohort study of incident adult PD patients followed-up between January 2010 and January 2020. One hundred and thirty-six patients, followed-up for at least three years, were included. Patients with malignancy and who had less than 1.7 Kt/V per week were excluded. Peritonitis is defined according to the "International Society Peritoneal Dialysis" guideline. According to the baseline PET, patients were divided into two groups as follows; 1) high or high average transporters and 2) low or low average transporters. Risk factors for peritonitis, five years, and overall technical survival of both modalities according to baseline transport status were determined. Results The mean age was 35.5±12 years, and the median follow-up time was 47 (36-178) months. Sixty-six (48%) of the patients were female. Patients' first-year Kt/V per week was 2.18±0.4, and the mean ultrafiltration was 0.9±0.4 liters. 26 (19%) of the patients had diabetes mellitus, 57(42%) patients had hypertension, and 27 (20%) of the patients had a history of hemodialysis of more than three months. 89 (65%) of the patients were performing CAPD, 59 (66%) of whom were low or low-average transporters. 47(35%) of patients were performing APD and 28(60%) of whom were high or high-average transporters. During the follow-up, a total of 71 peritonitis episodes were observed, and the incidence of peritonitis was 0.13 episodes/year. Univariate logistic regression analysis showed that CAPD, low education level (being primary school graduate or illiterate), HD treatment before PD, and bathing less than once per week were associated with peritonitis risk. However, multivariate analysis of associated factors demonstrated that only CAPD was a significant risk factor for peritonitis [odds ratio:2.360 (95% confidence interval:1.075-5.180), p=0.03]. Kaplan-Meier survival analysis showed that low or low-average transporters and high or high-average transporters had similar technical survival rates in both CAPD or APD at the end of three years (figure 1). Similar rates were found in overall survival. Conclusion In our study, APD and CAPD patients had similar technical survival regardless of the peritoneal transport characteristics. However, CAPD was found to be a factor for peritonitis. Thus, it may be appropriate to initiate the PD treatment with APD modality and evaluate patients to switch modalities with PET only in case of peritoneal dialysis inadequacy.

Orosomucoid can predict baseline peritoneal transport characteristics in peritoneal dialysis patients and reduce peritoneal proteins loss

Peritoneal dialysis (PD) is a replacement therapy for end-stage renal disease patients. In the first 4–8 weeks of PD, the patients were given an empirical dialysis prescription due to unknown peritoneal transport characteristics. Proteomic analysis could be used to identify serum biomarkers. In a discovery set, patients were divided into three groups according to the peritoneal equilibration test (PET) results: high (H), high average (HA), low average and low (LA&L) groups. A total of 1051 identified proteins were screened by Nano HPLC-MS/MS. The top two proteins among different peritoneal transport characteristics were Orosomucoid 2 (ORM2) and C-reactive protein (CRP). In a validation set, CRP was significantly elevated in H group than LA&L group, consistent with proteomic analysis. Serum ORM2 was enhanced in LA&L group compared with H and HA group. The expression of ORM2 in peritoneum was also enriched in LA&L group. At last, supplying exogenous ORM could reduce peritoneal proteins loss, without causing a pro-inflammatory response in mice. ORM2 and CRP could be used as biomarkers to predict the baseline peritoneal transport characteristics, and guide the early PD treatment. ORM may serve as a novel therapeutic target for decreasing peritoneal proteins loss in PD patients. SignificancePeritoneal dialysis (PD) is associated with the functional alterations of the peritoneum. PD patients were often given an empirical dialysis prescription due to the unknown peritoneal transport characteristics in the first 4–8 weeks since PD started. Therefore, it is urgently needed to find biomarkers to predict the baseline peritoneal transport characteristics. In this study, we employed a proteomic analysis to identify serum biomarkers in a training set and verified the screened biomarkers in a validation set. We also found that Orosomucoid (ORM) has the potential to decrease peritoneal proteins loss in PD therapy.

Peritoneal Membrane Transport Characteristics in Uni-PET with Preceding Icodextrin Dwell as Compared to Classic PET with Preceding Glucose Dwell: A Prospective Study

Peritoneal Membrane Transport Characteristics in Uni-PET with Preceding Icodextrin Dwell as Compared to Classic PET with Preceding Glucose Dwell: A Prospective Study

Does Prior Abdominal Surgery Influence Peritoneal Transport Characteristics or Technique Survival of Peritoneal Dialysis Patients?

Introduction: Prior abdominal surgery may result in peritoneal membrane adhesions and fibrosis, compromising the success of peritoneal dialysis (PD). The impact of this factor on peritoneal membrane function and PD technique survival has not been adequately investigated. Methods: Following an observational, retrospective design, we studied 171 incident PD patients, with the main objective of analyzing the influence of prior abdominal surgical procedures (main study variable) on baseline and evolutionary peritoneal transport characteristics (main outcome) and PD patient and technique survival (secondary outcomes). Abdominal surgeries were categorized according to the degree of presumed injury to the peritoneal membrane. We also considered the additive effect of aggressions to the membrane during the first year on PD therapy. Results: All patients had a baseline peritoneal equilibration test with complete drainage at 60′, and 113 patients had a second study at the end of the first year. Sixty-one patients (35.7%) had a record of prior abdominal surgery, including 29 patients with at least one major intraperitoneal surgery, 22 having undergone minor intraperitoneal procedures, and 21 with a background of major abdominopelvic extraperitoneal surgery. We did not observe differences, at baseline or after 1 year, among patients with or without previous abdominal procedures regarding small solute transport, overall capacity of ultrafiltration, free water transport, small pore ultrafiltration, or peritoneal protein excretion. Stratified analysis, considering prior and first-year-on-PD peritoneal aggressions, did not reveal any differences, although in this case our analysis was hampered by a limited statistical power. Abdominal surgical events did not influence patient or PD technique survival. Conclusion: Prior abdominal surgical procedures do not appear to compromise peritoneal membrane function or technique survival in patients successfully started on PD.

Peritoneal Transport Characteristics at the Beginning and in Long Term Peritoneal Dialysis: a Single Center Experience.

Introduction:Peritoneal dialysis (PD) is an established treatment for patients with end-srage kidney disease. The method was developed as an alternative to hemodialysis (HD) presenting a patient survival rate equivalent to HD and better preservation of residual renal function. Peritoneal dialysis (PD) patients have different peritoneal membrane permeability (transport) characteristics. High peritoneal membrane permeability is associated with increased mortality risk in the patient population.Aim:The aim of this study was to analyze the importance of the peritoneal membrane transport status in patients treated with continuous ambulatory peritoneal dialysis (CAPD).Methods:The study included 60 adult continuous ambulatory peritoneal dialysis (CAPD) patients, 29 male and 31 female, mean age 56.63±15.06 years. All patients treated with conventional glucose- based PD fluids. For the short term (within 3 month after start of PD) and long term (more than 12 months) peritoneal dialysis analysis of peritoneal transport characteristics has been used peritoneal functional test (PFT). With the test, categorisation of patients was possible into high (H), high-average (HA), low average (LA), and low (L) transporters.Results:Dialysate–to plasma ratio (D/P) of creatinine showed significantly increased over time (0.654±0.141 vs... 0.705±0.13, p<0.001). In multivariate analysis age, gender, time on dialysis, comorbid diseases, diabetes mellitus (DM), serum albumin, were considered as independent factors influencing the PFT. The high transporter group had higher D/Pcreat (H 0.84±0.03 vs... LA 0.57±0.05, p<0.001), higher proportion of man (H 100% vs... LA 39.5%, p<0.05), higher proportion of patients with comorbid diseases (H 60% vs... LA 20.9%, p<0.05), lower serum albumin concentration (H 29±6.0 vs... LA 37±5.2, p<0.001), lower D4/D0 glucose ( H 0.23±0.07 vs... LA 0.42±0.14, p<0.001), and lower drained volume (H 600±173 vs... LA 1016±355, p<0.001).Conclusion:The PFT was en easy, inexpensive, reliable test to assess peritoneal transport type and it also provided information about peritoneal clearance of solutes and ultrafiltration. Peritoneal transport type classification was recognized not only as aid for prescription, but also as a prognostic index.

Determinants of volume status in peritoneal dialysis: A longitudinal study.

In peritoneal dialysis (PD), fluid overload is frequent and associated with cardiac dysfunction and mortality. As it is considered a modifiable risk factor, we wished to describe clinical determinants of fluid overload in a longitudinal cohort of PD outpatients. We consecutively included PD outpatients treated with continuous ambulatory PD (CAPD) or automated PD (APD) attending for their routine clinical visit at a single tertiary hospital. Extracellular water (ECW) to total body water (TBW) ratio was measured by multifrequency bioelectrical impedance. Peritoneal transport characteristics were measured with a standard peritoneal equilibration test. Patients had a second follow-up visit with the same measurements. Univariable and multivariable mixed linear regression models were conducted with ECW/TBW as the dependent variable. A total of 155 patients were enrolled with a median follow-up time of 12 months. Median dialysis vintage was 13.5 ± 3.4 months. Overall mean value of ECW/TBW was 39.3% ± 1.1. In multivariable analysis, factors positively associated with ECW/TBW were: Age (P < .001), diabetes (P = .002), and SBP (P = .028). Factors negatively associated with ECW/TBW were: nPNA (P = .001), serum albumin (P < .001) and PTH (P = .014). None of the considered variable showed a significant interaction with time. We confirm a high prevalence of fluid overload in PD patients and show that it is strongly associated with older age, diabetes, hypoalbuminemia and protein energy wasting. In contrast, when PD prescription is tailored to patient's individual characteristics, residual renal function, PD modality and peritoneal characteristics are not decisive in controlling volume status.

Longitudinal Changes of NF-\u03baB Downstream Mediators and Peritoneal Transport Characteristics in Incident Peritoneal Dialysis Patients

The role of intra-peritoneal mediators in the regulation peritoneal transport is not completely understood. We investigate the relation between longitudinal changes in dialysis effluent level of nuclear factor kappa-B (NF-κB) downstream mediators and the change in peritoneal transport over 1 year. We studied 46 incident PD patients. Their peritoneal transport characteristics were determined after starting PD and then one year later. Concomitant dialysis effluent levels of interleukin-6 (IL-6), cyclo-oxygenase-2 (COX-2) and hepatocyte growth factor (HGF) are determined. There were significant correlations between baseline and one-year dialysis effluent IL-6 and COX-2 levels with the corresponding dialysate-to-plasma creatinine level at 4 hours (D/P4) and mass transfer area coefficient of creatinine (MTAC). After one year, patients who had peritonitis had higher dialysis effluent IL-6 (26.6 ± 17.4 vs 15.1 ± 12.3 pg/ml, p = 0.037) and COX-2 levels (4.97 ± 6.25 vs 1.60 ± 1.53 ng/ml, p = 0.007) than those without peritonitis, and the number of peritonitis episode significantly correlated with the IL-6 and COX-2 levels after one year. In contrast, dialysis effluent HGF level did not correlate with peritoneal transport. There was no difference in any mediator level between patients receiving conventional and low glucose degradation product solutions. Dialysis effluent IL-6 and COX-2 levels correlate with the concomitant D/P4 and MTAC of creatinine. IL-6 and COX-2 may contribute to the short-term regulation of peritoneal transport.

Peritoneal Transport Characteristics at the Beginning and in Long Term Peritoneal Dialysis: a Single Center Experience

Peritoneal Transport Characteristics at the Beginning and in Long Term Peritoneal Dialysis: a Single Center Experience

Randomized controlled trial to compare the tolerability and efficacy of treatment with Icodextrin 7.5% versus Dextrose 2.5% in chronic peritoneal dialysis patients with high/high average solute transport characteristics and low residual renal function

Aim: Comparison of tolerability and efficacy of treatment with icodextrin vs. dextrose 2.5% amongst high risk cohort of chronic peritoneal dialysis patients (high/high average solute transport characteristics and low residual renal function) over 3 months. Study Design and Methodology: The study was an open-label, comparative, prospective, randomized controlled trial, conducted at department of Nephrology, Postgraduate Institute of Medical Education and Research, Chandigarh, India. A total of 349 end stage renal disease patients on chronic peritoneal dialysis were screened for eligibility over a period of 6 months and 41 patients with high / high average solute transport characteristics and low residual renal function were randomized to receive either icodextrin 7.5% solution or 2.5% dextrose solution in long dwell. Patients were assessed for adequacy of peritoneal dialysis (creatinine & urea clearance), peritoneal membrane transport characteristics including solute clearance (standard peritoneal equilibration test), body composition, total body water, fat mass and fat free mass (using whole body tetrapolar bioimpedance analyzer) at baseline and at the end of 3 months. Statistical Analysis: Continuous variables were compared with independent samples paired t test if normally distributed, or with Mann–Whitney U test if the distribution was skewed. Categorical variables were analyzed with Chi-square test or Fisher exact test as appropriate. Pearson's correlation coefficient was calculated between different quantitative variables. Paired t test and Wilcoxon signed-rank test were used for within-group comparisons. Repeated measure ANOVA was used to compare bioelectrical impedance between intervention groups. Results: The study has shown that use of icodextrin based continuous ambulatory peritoneal dialysis resulted in better ultrafiltration and improved solute clearance when compared to 2.5% dextrose based peritoneal dialysis in a select cohort of patients having high/high average transporter characteristics with poor residual renal function, however, it didn't significantly alter total body water and failed to translate into improvements in either patient's or physician's assessment of global health of response to therapy atleast at 3 months. Conclusions: Although use of icodextrin based peritoneal dialysis solution for long dwell resulted in significant improvement in solute clearance and ultrafiltration nevertheless failed to translate into better hydration status or subjective improvement scores atleast at 3 months.

Unraveling Hepcidin Plasma Protein Binding: Evidence from Peritoneal Equilibration Testing.

Peptide hormone hepcidin regulates systemic iron metabolism and has been described to be partially bound to α2-macroglobulin and albumin in blood. However, the reported degree of hepcidin protein binding varies between <3% and ≈89%. Since protein-binding may influence hormone function and quantification, better insight into the degree of hepcidin protein binding is essential to fully understand the biological behavior of hepcidin and interpretation of its measurement in patients. Here, we used peritoneal dialysis to assess human hepcidin protein binding in a functional human setting for the first time. We measured freely circulating solutes in blood and peritoneal fluid of 14 patients with end-stage renal disease undergoing a peritoneal equilibration test to establish a curve describing the relation between molecular weight and peritoneal clearance. Calculated binding percentages of total cortisol and testosterone confirmed our model. The protein-bound fraction of hepcidin was calculated to be 40% (±23%). We, therefore, conclude that a substantial proportion of hepcidin is freely circulating. Although a large inter-individual variation in hepcidin clearance, besides patient-specific peritoneal transport characteristics, may have affected the accuracy of the determined binding percentage, we describe an important step towards unraveling human hepcidin plasma protein binding in vivo including the caveats that need further research.