Peritoneal Protein Loss With Time in Peritoneal Dialysis.

Longitudinal evolution of peritoneal protein loss (PPL), a reflection of hydrostatic pressure-driven leak of plasma proteins through the large-pore pathway, is not clear. Time on PD causes loss of mesothelial cells, vasculopathy, and increased thickness of the submesothelial fibrous layer. Are these structural changes associated with progressive increase of PPL, in a parallel with the rise in the D/P creatinine? The aim of the present study was to identify longitudinal changes of PPL over time. This single-center, longitudinal study included 52 peritoneal dialysis (PD) patients with a median follow-up of 26.5 months, evaluated at two different time points with a minimum interval of 6 months. Repeated measures analysis was performed using paired sample t-test or the nonparametric Wilcoxon signed-rank test, depending on the distribution. After a median interval of 15.5 months, lower levels of residual renal function and urine volume, lower Kt/V, and creatinine clearance were found. D/P creatinine and PPL were stable, but a decrease in ultrafiltration was present. Systemic inflammation, nutrition, and volume overload showed no significant change with time on PD. Analysis of a subpopulation with over 48 months between initial and subsequential assessment (n = 11) showed again no difference in inflammation, nutritional and hydration parameters from baseline, but importantly PPL decreased after more than 4 years on PD (mean difference 1.2 g/24, p = 0.033). D/P creatinine and dip of sodium remained unchanged. The absence of deleterious effects of time on PD is reassuring, pointing to the benefit of updated PD prescription, including the standard use of more biocompatible solutions towards membrane preservation and adjusted prescription avoiding overhydration and inflammation while maintaining nutritional status. After controlling for confounders, PPL may act as a biomarker of acquired venous vasculopathy, even if small pore fluid transport rates and free water transport are preserved.

Assisted PD throughout Europe: advantages, inequities, and solution proposals.

BACKGROUND: Peritoneal dialysis provides several benefits for patients and should be offered as first line kidney replacement therapy, particularly for fragile patients. Limitation to self-care drove assisted peritoneal dialysis to evolve from family-based care to institutional programs, with specialized care givers. Some European countries have mastered this, while others are still bound by the availability of a volunteer to become responsible for treatment. METHODS: A group of leading nephrologists from 13 European countries integrated real-life application of such therapy, highlighting barriers, lessons learned and practical solutions. The objective of this work is to share and summarize several different approaches, with their intrinsic difficulties and solutions, which might helpperitoneal dialysis units to develop and offer assisted peritoneal dialysis. RESULTS: Assisted peritoneal dialysis does not mean 4 continuous ambulatory peritoneal dialysis exchanges, 7 days/week, nor does it exclude cycler. Many different prescriptions might work for our patients. Tailoring PD prescription to residual kidney function, thereby maintaining small solute clearance, reduces dialysis burden and is associated with higher technique survival. Assisted peritoneal dialysis does not mean assistance will be needed permanently, it can be a transitional stage towards individual or caregiver autonomy. Private care agencies can be used to provide assistance; other options may involve implementing PD training programs for the staff of nursing homes or convalescence units. Social partners may be interested in participating in smaller initiatives or for limited time periods. CONCLUSION: Assisted peritoneal dialysis is a valid technique, which should be expanded. In countries without structural models of assisted peritoneal dialysis, active involvement by the nephrologist is needed in order for it to become a reality.

Protein Loss in Peritoneal Effluent: Different Meaning for 24-h versus PET Samples.

INTRODUCTION: Quantification of peritoneal protein loss (PPL) may be expressed according to a timely collection (24-h measurement or 4-h PET assessment) and as a concentration. The aim of this study was to compare the quantification methods of 24-h and 4-h collections. METHODS: This study included 81 prevalent peritoneal dialysis patients. Demographics and clinical and bioelectrical impedance features were registered. PPL was measured (4-h PET and 24-h results) and peritoneal protein clearance was calculated. A linear regression model was performed. RESULTS: Age and continuous ambulatory peritoneal dialysis (compared to cycler) were positively associated with greater PPL on 24-h collections. Neither cardiovascular disease, hypertension, diabetes nor the comorbidity Charlson Index was significantly associated with PPL. There was a consistent univariable relationship with D/P creatinine, whichever sampling method was used. Only 24-h measurements of PPL correlated with body composition variables. In multiple linear regression analysis, D/P creatinine association with PPL stands out. On the other hand, 24-h determinations (in grams or clearance) were associated with overhydration. PET protein quantification was associated with peritoneal creatinine clearance. DISCUSSION/CONCLUSION: Different methods sign different pathophysiological pathways. PET protein loss quantification should be regarded as a marker of peritoneal membrane intrinsic permeability. Measurements of a 24-h sample might be closer to patients' clinical status and prognosis, signalizing opportunities for therapy intervention.

Peritoneal Protein Loss, Inflammation, and Nutrition: Refuting Myths.

Peritoneal protein loss (PPL) has been correlated with mortality, malnutrition and inflammation. More recently overhydration was brought to the equation. This study aims to review classic and recent factors associated with PPL. Prevalent and incident peritoneal dialysis (PD) patients were included. Dialysate and serum IL-6 was obtained during PET. Hydration and nutritional status were assessed by bio-impedance. Linear regression and Cox regression were performed. The 78 included patients presented median values of PPL 4.8 g/24 h, serum IL-6: 5.1 pg/mL, and IL-6 appearance rate 153.5 pg/min. Mean extracellular water excess (EWexc) was 0.88 ± 0.94 L, and lean body mass index (LBMI) 17.3 ± 2.4 kg/m2. After mean follow-up of 33.9 ± 29.3 months, 12 patients died. Linear univariable analysis showed positive associations between PPL and small solute transport, body composition (LBMI and EWexc), comorbidities and performing CAPD (vs. cycler). PPL correlated positively with dialysate appearance rate of IL-6, but not with serum IL-6. Linear multivariable analysis confirmed positive association between PPL and EWexc (p = 0.012; 95%CI: 4.162-31.854), LBMI (p = 0.008; 95%CI: 1.720-11.219) and performing CAPD (p = 0.023; 95%CI: 4.375-54.190). In survival analysis, no relationship was found between mortality and PPL. Multivariable Cox regression showed Charlson Comorbidity Index (HR: 1.896, 95%CI: 1.235-2.913), overhydration (HR: 10.034, 95%CI: 1.426-70.587) and lower PPL (HR: 0.576, 95%CI: 0.339-0.978) were predictors for mortality. Overhydration, was a strong predictor of PPL, overpowering variables previously reported as determinants of PPL, namely clinical correlates of endothelial dysfunction or local inflammation. PPL were not associated with malnutrition or higher mortality, emphasizing the importance of volume overload control in PD patients.

Overhydration May Be the Missing Link between Peritoneal Protein Clearance and Mortality.

INTRODUCTION: Peritoneal protein loss (PPL) has been associated with mortality. Inflammation was assumed a putative cause with malnutrition as a consequence. Hydrostatic convection is a major drive for microvascular protein transport, but most studies in peritoneal dialysis (PD) patients overlooked this mechanism. An association between peritoneal protein clearance (PPCl) and venous congestion has been reported recently. The aim of this study was to explore the importance of fluid overload in PPCl in PD. METHODS: Sixty-seven prevalent PD patients were assessed with peritoneal equilibration test and multifrequency bioelectrical impedance assessment (BIA). PPL and PPCl were calculated from simultaneously obtained 24-h peritoneal effluent. RESULTS: PPL averaged 5.2 g/24 h. It was higher in patients on continuous treatment than in those without a long dwell. Significant associations between PPCl and BIA parameters of overhydration were found in both univariable and multivariable analyses. Lean mass index, partly dependent on hydration status, was associated with PPCl in univariable but not in multivariable analysis. A multiple linear model identified extracellular water excess and higher D/P creatinine as predictors of higher PPCl, independent of PD duration, type of PD, age, gender, albumin, cardiovascular disease, C-reactive protein, or lean mass index. CONCLUSIONS: The uni- and multivariable strong associations between fluid overload and PPCl support the importance of hydrostatic pressure-induced convection for PPCl. Also, peritoneal small solute transport was associated with PPCl. Both are amenable by adjusted dialysis prescription, especially focused on fluid status and avoidance of overhydration. The assumption of an association with inflammation and malnutrition was not confirmed.

Acquired perforating dermatosis with associated complicated cellulitis and amputation in a hemodialysis patient.

INTRODUCTION: Cutaneous manifestations related to chronic kidney disease (CKD) are common and associated with high morbidity. Acquired perforating dermatosis (APD) occurs mostly in diabetic or CKD patients, namely those undergoing hemodialysis. CASE REPORT: A 58-year-old male with type 2 diabetes, with long-term insulin use, several microvascular and macrovascular complications, and on maintenance hemodialysis for 5 years presented with a 1-week history of painful, pruritic, umbilicated papules and some punctiform necrotic lesions on his left forearm, both hands, and both amputation stumps. There was no evidence of infection or vascular alterations, and the patient was not responsive to an initial course of topical corticosteroid. These lesions rapidly evolved to larger, coalescent necrotic injuries, with aggravated pain, intense left-hand skin peeling, and the appearance of similar lesions in the trunk, requiring hospital admission. Calciphylaxis and APD were suspected. Skin biopsy was performed and directed treatment initiated, including intradialytic sodium thiosulfate. Histology findings were compatible with APD and also excluded findings suggestive of vasculitis or calciphylaxis. Soon after, difficult-to-treat cellulitis of the left hand and forearm progressed to critical ischemia and amputation. Microbiology analysis revealed Serratia marcescens as the causative agent. DISCUSSION: To our knowledge, there are no previously described cases of APD-related cellulitis. Its treatment can be particularly challenging, as lesions can persist and relapse, and chronic scars can develop. S. marcescens behaves as an opportunistic and difficult-to-treat pathogen, complicating the prognosis. CONCLUSION: APD can be associated with cellulitis and all of its complications in patients with underlying severe vasculopathy. Awareness of this complication in APD with early referral and aggressive treatment might improve the outcomes and quality of life of such patients.

Persistent exit-site infection in peritoneal dialysis - An unrecognized window to abdominal viscera.

Exit-site (ES) infection is a common complication in peritoneal dialysis (PD). Pseudomonas spp. is particularly difficult to treat, and catheter removal should be considered in persistent infections. The authors present a chronic ES infection resistant to directed antibiotic therapy in which catheter salvage was not possible. Removal was very difficult due to the presence of white sponge-like tissue with petrous consistency surrounding the catheter, all the way into the peritoneum. Histology revealed well-differentiated adenocarcinoma infiltrates. Abdominal computed tomography scan revealed a solid pancreatic (tail) lesion, nodular images on the greater epiploon, an adnexal lesion and a hepatic solid lesion, consistent with metastasis. The patient was referred for palliative care but maintained PD until untreatable pain and deterioration of general status aroused. Somewhere along the course of a chronic ES infection, the peritoneal catheter (and inflammation) was the metastatic path of an unknown pancreatic cancer, with neoplastic tissue reaching the skin. Catheter removal was crucial for diagnosis.

Paricalcitol and Peritoneal Protein Loss in Peritoneal Dialysis: A Double-Center Study.

BACKGROUND/AIMS: Peritoneal protein loss (PPL) is associated with cardiovascular disease and mortality in peritoneal dialysis (PD). Controversial results have been published about the effect of paricalcitol in PPL among PD patients. This study intends to analyze the relationship between paricalcitol and PPL in PD. METHODS: In a retrospective study, prevalent PD patients were divided into 2 groups: "with paricalcitol" and "without paricalcitol". X2-test, Student's t test, Pearson correlation coefficient and Logistic Regression analysis were applied. RESULTS: Eighty-two patients were included. PPL was lower among patients medicated with paricalcitol (5.17 ± 1.71 vs. 6.79 ± 2.10 g/24 h, p = 0.0001). In multivariate analysis, paricalcitol and dialysate/plasma ratio of creatinine (D/P creatinine) were independently related to PPL (OR 4.270 [1.437-12.684], p = 0.009 and OR 0.205 [0.064-0.659], p = 0.008, respectively), adjusted for diabetes. CONCLUSION: Paricalcitol and D/P creatinine were independently related to PPL. Paricalcitol may have an effect on PPL in PD patients.