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

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.

P1160INCREASED REMOVAL RATES OF FLUID AND SODIUM DURING STEADY CONCENTRATION PERITONEAL DIALYSIS COMPARED TO ICODEXTRIN AND PERITONEAL EQUILIBRATION TEST

Background and Aims Removal of fluid and sodium may be a major challenge in PD, which can be addressed using icodextrin for the long dwells. Steady concentration PD (SCPD) with Carry Life® UF is a novel treatment modality where the intraperitoneal glucose concentration can be kept stable throughout the treatment maintaining ultrafiltration and sodium removal. This is performed by transferring a small volume of the dialysate into the device, where glucose is added and the dialysate returned to the patient. The present study was performed to compare the effect of SCPD with icodextrin and peritoneal equilibration test (PET) on ultrafiltration and sodium removal. Method Eight stable PD patients (high or high average transporters) were included in the study. Subjects were treated with three 5-hour Carry Life UF treatments using three different glucose doses (11, 14, 20 g/h). An initial fill with 1500 ml, 1.36% glucose PD solution was used. A small volume of dialysate was drained hourly to avoid overfill. An icodextrin 11-hour dwell (2000 ml, 7.5% Extraneal®), and a 4-hour PET (2000 ml, 2.27% glucose PD solution), were used as controls. Data expressed as mean ± SD, statistical analysis using one-way ANOVA, **p<0.01, ***p<0.001. Results The treatment time for icodextrin was 11.4±1.5 hours, for PET 4.1±0.1 hours, and for the Carry Life UF treatments 5.2±0.3 hours. Carry Life UF treatments generated increased ultrafiltration rates compared to icodextrin and PET (Figure a). The sodium removal rates with Carry Life UF treatments were also significantly increased compared to icodextrin and PET (Figure b). However, the total ultrafiltration volumes during Carry Life UF treatments were not significantly different compared to the icodextrin dwell (646±256, 739±312, 863±380, 595±239, ml/treatment for 11 g/h, 14 g/h, 20 g/h, and icodextrin, respectively). The ultrafiltration volume during PET was significantly lower than all other treatments (162±242 ml, p<0.001). Peritoneal sodium removal did not differ between Carry Life UF treatments and the icodextrin dwells (86±27, 92±33, 110±37, 88±34 mmol/treatment for 11 g/h, 14 g/h, 20 g/h, and icodextrin, respectively). Peritoneal sodium removal during PET was significantly lower than during the other treatments (22±33 mmol/treatment, p<0.01). Conclusion Treatments performed with Carry Life UF maintain a stable intraperitoneal glucose concentration during the entire dwell, resulting in higher ultrafiltration and sodium removal rates than for controls (PET and icodextrin). The fluid and sodium was removed during the 5-hour Carry Life UF treatments was comparable to the 11-hour icodextrin dwells. In summary, the increased removal rates of fluid and sodium during SCPD result in a more efficient treatment than conventional CAPD or icodextrin.

P1131STEADY CONCENTRATION PERITONEAL DIALYSIS INCREASES ULTRAFILTRATION AND SODIUM REMOVAL COMPARED TO CAPD

Background and Aims Fluid and sodium removal may be a challenge during glucose-based PD, leading to increased use of high glucose solutions to maintain sufficient fluid removal. This may in turn lead to increased sodium sieving, resulting in a decreased sodium removal. Carry Life® UF uses Steady Concentration PD (SCPD), where the infusion of glucose compensates for glucose uptake and maintains the intraperitoneal glucose concentration at a sufficient level providing a continuous ultrafiltration throughout the dwell. The present study investigated the effect of Carry Life UF compared to a standard CAPD dwell regarding ultrafiltration, sodium removal and glucose absorption. Method Eight stable PD patients were included in the study. Subjects were treated with 5-hour Carry Life UF treatments using three different glucose doses (11, 14, 20 g/h). An initial fill with 1500 ml, 13.6 g/l glucose PD solution was used. A small volume of dialysate was drained hourly to avoid overfill. A standard 4-hour Peritoneal Equilibration Test (PET) (2000 ml, 22.7 g/l glucose) was used as control. Data expressed as mean ± SD, statistical analysis using one-way ANOVA. Results Ultrafiltration was significantly increased during the Carry Life UF treatments compared to PET (646±256, 739±312, 863±380 ml for 11 g/h, 14 g/h and 20 g/h, respectively, vs. 162±242 ml for PET, p<0.01). Sodium removal increased significantly during Carry Life UF treatments (86±27, 92±33, 110±37 mmol/dwell for 11, 14, and 20 g glucose/h) compared to PET (22±33 mmol/dwell, p<0.001). Figure a shows that the intraperitoneal glucose concentration increased during the first hours of the Carry Life UF treatments and remained stable during the remainder of the treatments. During PET the glucose concentration decreased gradually during the treatment. The maximum intraperitoneal glucose concentration did not exceed 26 g/l (144 mmol/l) during the Carry Life UF treatments. The UF volume per gram of glucose uptake was significantly higher for the two lower Carry Life UF glucose doses compared to PET (Figure b). Conclusion SCPD performed with Carry Life® UF maintained a stable intraperitoneal glucose concentration during the 5-hour treatment which generated significantly higher UF volumes compared to 4-hour PET. During the Carry Life UF treatments glucose was used more efficiently, particularly for the two lowest doses, in comparison to PET. The increased sodium removal with Carry Life® UF enables a better balance between UF volume and sodium removal than for example during APD. In summary, SCPD using Carry Life® UF increases the efficiency of PD compared to standard, glucose-based CAPD with respect to ultrafiltration and sodium removal.

Clinical relevance of marginal factors on ultrafiltration in peritoneal dialysis

Background: Ultrafiltration (UF) in peritoneal dialysis (PD) is mainly driven by the osmotic gradient and peritoneal permeability, but other factors—such as intraperitoneal pressure (IPP)—also have an influence. Methods: To assess the clinical relevance of these marginal factors, we studied 41 unselected PD patients undergoing two consecutive 2 h, 2.27% glucose exchanges, first with 2.5 L and then with 1.5 L. Results: IPP, higher in the 2.5 L exchange, had a wide interpatient range, was higher in obese and polycystic patients and their increase with infusion volume was higher for women regardless of body size. UF with 2.5 L correlated inversely with IPP and was higher for patients with polycystosis or hernias, while for 1.5 L we found no significant correlations. The effluent had higher glucose and osmolarity in the 2.5 L exchange than in the 1.5 L one, similar for both sexes. In spite of this stronger osmotic gradient, only 21 patients had more UF in the 2.5 L exchange, with differences up to 240 mL. The other 20 patients had more UF in the 1.5 L exchange, with stronger differences (up to 800 mL, and more than 240 mL for 9 patients). The second group, with similar effluent osmolarity and peritoneal equilibration test (PET) parameters than the first, has higher IPP and preponderance of men. The sex influence is so intense that men decreased average UF with 2.5 L with respect to 1.5 L, while women increased it. Conclusions: With 2.27% glucose, sex and IPP—modulated by obesity, polycystosis, hernias, and intraperitoneal volume—significantly affect UF in clinical settings and might be useful for its management.

Monitoring of Intraperitoneal Fluid Volume during Peritoneal Equilibration Testing using Segmental Bioimpedance

Background: Ultrafiltration failure and fluid overload are common in peritoneal dialysis (PD) patients. Knowledge of intraperitoneal volume (IPV) and time to peak IPV during a dwell would permit improved PD prescription. This study aimed to utilize trunk segmental bioimpedance analysis (SBIA) to quasi-continuously monitor IPV (IPVSBIA) during the peritoneal dwell. Methods: IPVSBIA was measured every minute using lower-trunk SBIA (Hydra 4200; Xitron Technologies Inc., CA, USA) in 10 PD patients during a standard 240-min peritoneal equilibration test (PET). The known dialysate volume (2 L) rendered IPVSBIA calibration and calculation of instantaneous ultrafiltration volume (UFVSBIA) possible. UFVSBIA was defined as IPVSBIA – 2 L. Results: Based on dialysate-to-plasma creatinine ratio, 2 patients were high, 7 high-average, and 1 low-average transporters. Technically sound IPVSBIA measurements were obtained in 9 patients (age 59.0 ± 8.8 years, 7 females, 5 African Americans). Drained ultrafiltration volume (UFVdrain) was 0.47 ± 0.21 L and correlated (r = 0.74; p < 0.05) with end-dwell UFVSBIA (0.55 ± 0.17 L). Peak UFVSBIA was 1.04 ± 0.32 L, it was reached 177 ± 61 min into the dwell and exceeded end-dwell UFVSBIA by 0.49 ± 0.28 L (95% CI: 0.27–0.7) and UFVdrain by 0.52 ± 0.31 L (95% CI: 0.29–0.76), respectively. Conclusion: This pilot study demonstrates the feasibility of trunk segmental bioimpedance to quasi-continuously monitor IPVSBIA and identify the time to peak UFVSBIA during a standard PET. Such new insights into the dynamics of intraperitoneal fluid volume during the dwell may advance our understanding of the underlying transport physiology and eventually assist in improving PD treatment prescriptions.