Post-dilution Online Hemodiafiltration Research Articles

Assessment of the Influence of Postdilution Online Hemodiafiltration on the Rate of Removal of Middle Molecular Weight Uremic Toxins

Abstract Hemodiafiltration is a method of treatment used to replace kidney function, which effectively removes uremic toxins of middle molecular weight from the blood of patients with the end-stage of chronic kidney disease. The aim of this study was to examine the effect of postdilution online hemodiafiltration on the degree of β2- microglobulin removal. Thirty patients treated with postdilution online hemodiafiltration were examined. The main parameter for assessing the removal efficiency of uremic toxins of middle molecular weight was the concentration of β2-microglobulin in the serum before and after a single session of postdilution online hemodiafiltration. The following tests were used for statistical analysis: Shapiro-Wilk test, Student’s T test for bound samples and Wilcoxon test. The average total convective volume is 21.38 ± 2.97 liters per session. The reduction index of β2-microglobulin during a single session of postdilution online hemodiafiltration is 70.86 ± 6.87%. The average loss of albumin during a single postdilution online hemodiafiltration is 2.50 ± 0.92 g/4h, and the albumin reduction index is 6.20 ± 2.12%. Postdilution online hemodiafiltration effectively removes β2-microglobulin from the blood of patients with end-stage chronic kidney disease. The reduction index of β2-microglobulin is ˜ 71.00% and the loss of albumin is less than 4.0 g/4h. This dialysis modality prevents the development of dialysis-related amyloidosis and atherosclerotic cardiovascular diseases in the population of patients treated with regular hemodiafiltration.

Comparison of citrate dialysate in pre- and post-dilution online hemodiafiltration: effect on clot formation and adequacy of dialysis in hemodialysis patients

Background Citrate dialysate (CD) has been successfully used in conventional hemodialysis and continuous renal replacement therapy; however, no study has compared pre- and post-dilution online hemodiafiltration (oL-HDF). Therefore, we aimed to investigate the efficacy of citrate anticoagulation for oL-HDF and the metabolic changes and quality of life of patients on hemodialysis treated using both modes Method Eight dialysis patients were treated with CD containing 0.8 mmol of citric acid for 4 weeks in each phase. Visual clotting scores were investigated as the primary endpoints. Adequacy of dialysis, laboratory parameters, and quality of life were measured as secondary objectives. Results The mean clotting scores in the pre-dilution mode were significantly lower than those in the post-dilution mode and in all phases except the heparin-free phase (p < 0.001 in the baseline phase, p = 0.001 in phase 1, and p = 0.023 in phase 2). The values of Kt/V in both modalities were comparable except during the baseline phase, in which the values of pre-dilution were significantly greater than post-dilution (2.36 ± 0.52/week vs. 1.87 ± 0.33/week;95% CI −0.81 to −0.19, p = 0.002). The patient’s quality of life regarding their physical activity level was significantly higher in the post-dilution mode than in the pre-dilution mode at baseline and in phase 1 (p = 0.014 and 0.004 at baseline and in phase 1, respectively). Metabolic changes did not differ between the two modes. Conclusion Citrate dialysate decreased or prevented anticoagulation in both pre- and post-dilution modes of oL-HDF without significant side effects and had comparable adequacy of dialysis.

Anti-inflammatory effect of high flux dialyzer surface area 2.6m2 in high flux hemodialysis and hemodiafiltration

Dialysis therapy has remarkably evolved through the innovation in dialyzers and hemodialysis modalities, enhancing patients’ quality of life. The efficacy of dialysis can be determined by measuring the reduction ratio (RR) of middle molecules such as Interleukin-6 (IL-6) and Procalcitonin. In our study, we tested a high-flux dialyzer, BIOPURE (Biorema) 260 HF, with a surface area (SA) of 2.6 m2, in terms of IL-6 and Procalcitonin removal while performing high-flux hemodialysis (HF-HD) and post-dilution online hemodiafiltration (OL-HDF). This crossover study comprised 25 patients who received a session of HF-HD using the BIOPURE (Biorema) 260 H, followed by a session of post-dilution OL-HDF. A washout period of 2 weeks was instilled between the two sessions, during which the patients received HF-HD using high-flux dialyzers (maximum SA 2.0 m2). All patients’ pre/post dialysis concentrations of IL-6 and procalcitonin were measured. The dialyzer used in this study resulted in a significant IL-6 RR of 44.92±5.11% (p&lt;0.001) with HDF and 32.48±5.72% (p&lt;0.001) with HF-HD; and a procalcitonin RR of 50.32±3.94% (p&lt;0.001) with HDF and 41.80±4.32% (p&lt;0.001) with HF-HD. In conclusion, the dialyzer BIOPURE (Biorema) 260 HF (SA 2.6 m2) is efficient in eliminating IL-6 and procalcitonin, especially with OL-HDF compared to HF-HD, with acceptable albumin loss in the dialysate.

Removal of α1-Microglobulin Using Post-Dilution Online Hemodiafiltration with Polymethylmethacrylate Membrane: An Open-Label, Single-Arm Study

Introduction: The removal of low- and medium-molecular-weight proteins has been improved with online hemodiafiltration (OL-HDF) and hemodialysis using high-flux membranes; however, the outcomes of patients with end-stage kidney disease (ESKD) undergoing dialysis treatment are still worse than in the general population. α₁-Microglobulin (α₁-m), with a molecular weight of 33,000 Da, may contribute to dialysis-related disorders and mortality. However, the removal is insufficient even with current OL-HDF using the polysulfone (PS) membrane, which is common in Japan. Polymethylmethacrylate (PMMA) membranes can remove medium- to high-molecular-weight proteins by adsorption. This study aimed to assess the efficacy of removing medium- to high-molecular-weight proteins, such as α₁-m and β₂-microglobulin (β₂-m), through post-dilution OL-HDF with PMMA (Post-PMMA). The assessment was conducted in comparison to pre-dilution OL-HDF with PS (Pre-PS), using an open-label, single-arm study. Methods: Seven patients with ESKD on Pre-PS underwent Post-PMMA with replacement volume of 30 mL/min (low flow) and 50 mL/min (high flow). Clearance and removal rates of α₁-m, β₂-m, small molecules, inflammatory cytokines, and albumin were measured at 60 and 240 min of treatment. Results: Clearance rates of α₁-m at 60 min were −2.8 ± 5.2 mL/min with Pre-PS, −0.4 ± 2.6 mL/min with Post-PMMA (low), and 0.6 ± 3.4 mL/min with Post-PMMA (high). The removal rate of α₁-m was higher in Post-PMMA than that in Pre-HDF-PS (Post-PMMA [high] 17.7 ± 5.9%, Post-PMMA [low] 15.0 ± 5.6%, and Pre-PS 4.1 ± 5.5%). Adsorption clearance of β₂-m was increased with Post-PMMA. Albumin leakage in Post-PMMA was not higher than that in Pre-PS. Conclusion: The removal rate of α₁-m with Post-PMMA was higher than that with Pre-PS. The PMMA membrane adsorbed β₂-m, suggesting the removal effect of medium- to high-molecular-weight proteins by the adsorption method. Since Post-PMMA effectively removes α₁-m without excessive albumin leakage, it will be useful for patients with ESKD, especially those with a poor nutritional status.

Comparison of Citrate Dialysate in Pre- and Post-Dilution Online Hemodiafiltration: Effect on Clot Formation and Adequacy of Dialysis in Hemodialysis Patients

Comparison of Citrate Dialysate in Pre- and Post-Dilution Online Hemodiafiltration: Effect on Clot Formation and Adequacy of Dialysis in Hemodialysis Patients

Efficacy of polymethylmethacrylate membrane hemodiafilter Filtryzer® PMF™-21A in improving pruritus in hemodialysis patients: a prospective interventional study

BackgroundHemodialysis-associated pruritus (HAP) occurs in 60–80% of hemodialysis patients. This significant complication not only decreases quality of life through sleep disturbance and depression, but also leads to poor survival outcomes. The polymethylmethacrylate (PMMA) membrane was the first synthetic polymer membrane for the hollow-fiber artificial kidney created in 1977. PMMA membrane dialyzers have been reported to be effective for improving various complaints, including pruritus, and nutritional status. In Japan, a PMMA membrane hemodiafilter Filtryzer® PMF™-A (PMF-A) was launched in November 2021 and subsequently became available for online hemodiafiltration (OHDF). This study aimed to determine whether PMF-A effectively improves pruritus in hemodialysis patients.MethodsParticipants were 20 patients (median age 74.5 years) on predilution OHDF (pre-OHDF) or postdilution OHDF (post-OHDF) using an Asymmetric Triacetate Membrane® hemodiafilter (FIX-210E eco or FIX-210S eco), who were experiencing pruritus of “very mild” or higher severity based on the Shiratori severity score either during the daytime or nighttime. After switching to post-OHDF with PMF-21A (substitution flow rate: 10 L/session), the substitution flow rate was gradually increased according to results of pruritus evaluation every 2 weeks over 3 months. The primary endpoint was the severity of pruritus evaluated using visual analogue scale (VAS) and the Shiratori severity score. Secondary endpoints included white blood cell count (WBC), hemoglobin level (Hb), platelet count (Plt), serum albumin level (Alb), high-sensitivity C-reactive protein (hsCRP), IL-6, dry weight (DW), and solute removal performance.ResultsThe median VAS score was significantly decreased 2 weeks after switching compared with baseline (44 mm) and remained significantly decreased at Week 12 (22 mm; p < 0.01). From baseline to Week 12, 16 patients (80%) showed improvement in VAS score. The percentage of patients with mild to moderate daytime pruritus according to the Shiratori severity score decreased significantly from 80.0% to 45.0% (p < 0.05), whereas no significant change was observed for nighttime pruritus (p = 0.267). Pre-dialysis serum β2-MG levels were significantly higher at Week 12 compared with baseline. No significant changes were observed in WBC, Hb, Plt, serum Alb, hsCRP, IL-6, or DW.ConclusionsOHDF with PMF-21A may be more effective in improving HAP.

Optical Real-Time Cardiorenal Toxin Uric Acid Measurement During Hemodialysis Using a Miniaturized Optical Sensor.

Patients with chronic kidney disease (CKD) are at higher cardiovascular risk than the general population. Cardiovascular diseases, vascular calcification among them, are the leading cause of death in these patients. Factors influencing vascular calcification are oxidative stress, inflammation, and accumulation of uremic toxins during CKD. Uric acid is a cardiorenal toxin that accumulates in the case of kidney malfunction. The primary therapy for replacing kidney function and removing toxins from end-stage renal disease patients is hemodialysis. Effective removal of toxins can be estimated by blood or dialysate lab analysis or optical monitoring. In this study, the authors tested a miniaturized optical sensor for monitoring uric acid levels and removal for the first time in a more extensive clinical study, including Hemodialysis (HD) and Post-dilutional online hemodiafiltration (HDF) procedures with different settings in Tallinn, Estonia. The results (Mean±SD, Lab vs. Sensor) of the uric acid concentration 57.20±34.05 vs. 57.22±33.09 µmol/L, reduction ratio 68.72±10.91 vs. 67.89±12.48 %, and total removed amount 7.00±2.10 vs. 7.33±2.29 mmol did not differ significantly from the values obtained from the clinical laboratory (p<0.05).Clinical Relevance-During this study, a miniaturized optical sensor was tested for the first time in the clinic in different dialysis settings. The results confirm that the sensor is reliable for regularly monitoring cardiorenal toxin uric acid removal during hemodialysis.

The effect of hemodiafiltration vs. high-flux hemodialysis on alpha 1-microglobulin level and dialysate albumin loss using a dialyzer surface area of 2.6 m²

Dialysis therapy has remarkably evolved through the innovation in dialyzers and hemodialysis modalities, enhancing patients’ quality of life. The efficacy of dialysis can be determined by measuring the reduction ratio (RR) of middle molecules, such as alpha 1-microglobulin (A1M). In this study, we tested a high-flux dialyzer, BIOPURE (Biorema) 260 HF, with a surface area (SA) of 2.6 m2, in terms of A1M removal and concurrent albumin loss in dialysate while receiving high-flux hemodialysis (HF-HD) and post-dilution online hemodiafiltration (OL-HDF). This crossover study comprised 25 patients who received a session of HF-HD using the BIOPURE (Biorema) 260 H, followed by a session of post-dilution OL-HDF. A washout period of 2 weeks was instilled between the two sessions, during which the patients received HF-HD using high-flux dialyzers (maximum SA 2.0 m2). All patients’ hourly dialysate albumin and pre/post dialysis concentrations of A1M were measured. The dialyzer used in this study resulted in significantly higher A1M RR of 41.9±7.93% with HDF than with HF-HD 27.12±7.65% (p&lt;0.001), and a median cumulative dialysate albumin loss of 2.97g (IQR 1.98 – 3.37), and 0.67g (IQR 0.49 – 1.13) with HDF and HF-HD, respectively. In conclusion, the dialyzer BIOPURE (Biorema) 260 HF (SA 2.6 m2) is efficient in eliminating A1M, especially with OL-HDF compared to HF-HD, with acceptable albumin loss in the dialysate.

Albumin Loss in Post-Dilution On-Line Hemodiafiltration Compared With Pre-Dilution On-Line Hemodiafiltration and Conventional Hemodialysis

Albumin Loss in Post-Dilution On-Line Hemodiafiltration Compared With Pre-Dilution On-Line Hemodiafiltration and Conventional Hemodialysis

Comparison of the pre-dilution and post-dilution methods for online hemodiafiltration.

Online hemodiafiltration (OL-HDF) is a treatment modality using diffusion and ultrafiltration. There are two types of dilution methods in OL-HDF: pre-dilution, which is commonly provided in Japan, and post-dilution, which is commonly provided in Europe. The optimal OL-HDF method for individual patients is not well studied. In this study, we compared the clinical symptoms, laboratory data, spent dialysate, and adverse events of pre- and post-dilution OL-HDF. We conducted a prospective study of 20 patients who underwent OL-HDF between January 1, 2019 and October 30, 2019. Their clinical symptoms and dialysis efficacy were evaluated. All patients underwent OL-HDF every 3months in the following sequence: first pre-dilution, post-dilution, and second pre-dilution. We evaluated 18 patients for the clinical study and 6 for the spent dialysate study. No significant differences in spent dialysates regarding small and large solutes, blood pressure, recovery time, and clinical symptoms were observed between the pre- and post-dilution methods. However, the serum α1-microglobulin level in post-dilution OL-HDF was lower than that in pre-dilution OL-HDF (first pre-dilution: 124.8 ± 14.3mg/L; post-dilution: 116.6 ± 13.9mg/L; second pre-dilution: 125.8 ± 13.0mg/L; first pre-dilution vs. post-dilution, post-dilution vs. second pre-dilution, and first pre-dilution vs. second pre-dilution: p = 0.001, p < 0.001, and p = 1.000, respectively). The most common adverse event was an increase in transmembrane pressure in the post-dilution period. Compared to pre-dilution, the post-dilution method decreased the α1-microglobulin level; however, there were no significant differences in clinical symptoms or laboratory data.

Systematic Comparison of Uremic Toxin Removal Using Different Hemodialysis Modes: A Single-Center Crossover Prospective Observational Study

Many hypotheses could explain the mortality decrease observed using hemodiafiltration, such as reduction of intradialytic hypotension and more efficient toxin removal. We led a systematic analysis of representative uremic toxin removal with hemodialysis (HD), online postdilution hemodiafiltration (postHDF) and online predilution hemodiafiltration (preHDF), in a single-center crossover and prospective observational study. The primary outcome was the reduction ratio of uremic toxins of the three categories defined by the Eutox group. Twenty-six patients were treated by those three techniques of extra renal epuration. Mean Kt/Vurea was not different between the treatment methods. Mean reduction ratio of beta2microglobulin was significantly higher for both HDF treatments than for HD (p < 0.001). Myoglobin, kappa, and lambda free light chain reduction ratio was significantly different between the modes: 37.75 ± 11.95%, 45.31 ± 11% and 61.22 ± 10.56%/57.21 ± 12.5%, 63.53 ± 7.93%, and 68.40 ± 11.79%/29.12 ± 8.44%, 34.73 ± 9.01%, and 45.55 ± 12.31% HD, preHDF, and postHDF, respectively (p < 0.001). Mean protein-bound solutes reduction ratio was not different between the different treatments except for PCS with a higher reduction ratio during HDF treatments. Mean albumin loss was always less than 2 g. HDF improved removal of middle molecules but had no effect on indoles concentration without any difference between synthetic dialysis membranes.

Assessment of the Influence of Asymmetric Triacetate Cellulose Membrane on the Rate of Removal of Middle Molecular Weight Uremic Toxins in Patients Treated with Postdilution Online Hemodiafiltration

BACKGROUND: Postdilution online hemodiafiltration (OL-HDF) effectively removes uremic toxins of middle molecular weight from the blood of patients with end-stage chronic kidney disease. The rate of removal of uremic toxins depends on the type of dialysis membrane, blood flow rate (Qb), net ultrafiltration flow rate (Qnuf), and total convective volume (Vconv). AIM: The aim of this study was to examine the efficacy of asymmetric triacetate cellulose dialysis membrane in patients on post-dilution OL-HDF. METHODS: Thirty-five patients treated with post-dilution OL-HDF hemodiafiltration for at least 3 months were examined. The main parameters for assessing the efficiency of removal of uremic toxins of middle molecular weight are the concentration of β2-microglobulin (β2-M) and interleukin-6 (IL-6) in serum before and after a single session of post-dilution OL-HDF. The followings were used for statistical analysis: Kolmogorov–Smirnov test, Student’s T test for bound samples and Wilcoxon test. RESULTS: The average Vconv was 20.90 ± 3.30 liters/session. The β2-M reduction index during a single session of postdilution OL-HDF was 71.10 ± 6.39%, the IL-6 reduction index was 43.75 ± 15.60%, and the albumin reduction index was 4.55 ± 2.31%. CONCLUSION: The asymmetric triacetate cellulose dialysis membrane effectively removes β2-M and IL-6 during a single session of postdilution OL-HDF. The β2-M reduction index is ∼70%, the IL-6 reduction index is ∼40%, and albumin loss is &lt;4.0 g/4 h. The examined dialysis membrane and dialysis modality prevent the development of amyloidosis associated with dialysis, microinflammation and reduce the risk of developing atherosclerotic cardiovascular diseases in the population of patients treated with regular hemodiafiltration.

Removal performance of pre- and post-dilution online hemodiafiltration using identical hemodiafilters in the same patients

Online hemodiafiltration (OHDF) for renal replacement therapy has two modes: pre- (pre-OHDF) and post-dilution OHDF (post-OHDF). To elucidate the precise differences between the two modes, a clinical study was performed using the same polysulfone hemodiafilters in the same patients. Eight patients were treated with ABH™-22PA for 6 weeks: 3 weeks of pre-OHDF (with substitution volumes of 24, 36, and 48 L) and 3 weeks of post-OHDF (6, 8, and 10 L). The reduction ratios of urea, uric acid (UA), creatinine (CRE), inorganic phosphorus (iP), beta-2-microglobulin (β2-MG), and alpha-1-microglobulin (α1-MG) were evaluated. The removal amounts of β2-MG, α1-MG, and albumin were also evaluated by analyzing the spent dialysis fluids. The types and numbers of adverse events (AEs) and device malfunctions were recorded. The reduction ratios of urea, UA, CRE, iP, and β2-MG were comparable among all conditions, while that of α1-MG tended to be slightly higher in post-OHDF than in pre-OHDF. The removal amounts of α1-MG and albumin in pre-OHDF and post-OHDF were significantly greater with the maximum substitution volume than with the minimum volume. However, the selective removal indices, which were obtained by dividing the amount of α1-MG removed by the albumin level, tended to be slightly higher in pre- than in post-OHDF. No device-related AEs or device malfunctions occurred in either mode. No significant differences in inflammatory responses, evaluated by high-sensitivity C-reactive protein and interleukin-6, were observed. This study provides removal performance and safety data regarding the application of ABH-22PA for pre- and post-OHDF.

The Medium Cut-Off Membrane Does Not Lower Protein-Bound Uremic Toxins.

The accumulation of protein-bound uremic toxins (PBUT) is associated with increased cardiovascular outcomes in patients on dialysis. However, the efficacy of PBUT removal for a medium-cutoff (MCO) membrane has not been clarified. This study was designed to assess the efficacy of PBUT clearance according to dialysis modalities. In this prospective and cross-over study, we enrolled 22 patients who received maintenance hemodiafiltration (HDF) thrice weekly from three dialysis centers. The dialysis removal of uremic toxins, including urea, beta 2-microglobulin (B2MG), lambda free light chain (λ-FLC), indoxyl sulfate (IS), and p-cresyl sulfate (pCS), was measured in the 22 patients on high-flux HD (HF-HD), post-dilution online HDF (post-OL-HDF), and MCO-HD over 3 weeks. The average convection volume in post-OL-HDF was 21.4 ± 1.8 L per session. The reduction rate (RR) of B2MG was higher in post-OL-HDF than in MCO-HD and HF-HD. The RR of λ-FLC was the highest in MCO-HD, followed by post-OL-HDF and HF-HD. The dialysate albumin was highest in MCO-HD, followed by post-OL-HDF and HF-HD. Post-dialysis plasma levels of IS and pCS were not statistically different across dialysis modalities. The total solute removal and dialytic clearance of IS and pCS were not significantly different. The clearance of IS and pCS did not differ between the HF-HD, post-OL-HDF, and MCO-HD groups.

Effects of high albumin leakage on survival between online hemodiafiltration and super high-flux hemodialysis: the HISTORY study

BackgroundAll-cause mortality is lower with a high substitution volume in predilution (pre) and postdilution (post) online hemodiafiltration (OHDF) than with hemodialysis (HD), and mortality does not significantly differ between pre- and post-OHDF groups. Despite the improved survival with a high substitution volume, there may be limitations. On the other hand, either normoalbuminemia or high albumin leakage in HD can reduce mortality, and super high-flux (SHF) membrane dialyzers can reduce mortality compared with low-flux and high-flux membrane dialyzers. Here, we investigated the associations of serum albumin concentration (s-Alb), albumin leakage, and substitution volume with all-cause mortality in OHDF and SHF-HD.MethodsIn a 3-year retrospective observational study of patients receiving dialysis from April 1 to July 1, 2017, we developed a propensity score-matched model using 783 stable patients (SHF-HD, 355; OHDF, 428). We used the log-rank test to compare Kaplan–Meier survival curves and Cox regression analysis to calculate hazard ratio (HR). Cox regression analysis was also used to compare the effect of estimated albumin leakage (EAL) and substitution volume on 3-year all-cause mortality.ResultsAll-cause mortality was significantly lower with high EAL than with low EAL (SHF-HD: P = 0.012, log-rank test; HR, 0.44; 95% confidence interval [CI] 0.23–0.85; OHDF: P = 0.027, log-rank test; HR, 0.41; 95% CI 0.18–0.93). The mortality of high EAL was not significantly different between high and low s-Alb in SHF-HD (3.5 ± 0.1 and 3.2 ± 0.2 g/dL) and OHDF (3.6 ± 0.2 and 3.2 ± 0.1 g/dL), despite significant differences in s-Alb. Mortality did not significantly differ between SHF-HD and OHDF with higher EAL ranges or a lower difference in EAL. Mortality in pre-OHDF was significantly correlated with EAL (P = 0.007, beta − 0.32) rather than substitution volume, and mortality in post-OHDF was not analyzed because of fewer deaths.ConclusionsThe results suggest that survival is improved more with high EAL than with low EAL in both OHDF and SHF-HD patients, that high EAL with mild-to-moderate hypoalbuminemia does not necessarily worsen survival in OHDF and SHF-HD patients, and that survival is equivalent between OHDF and SHF-HD patients with a similar level of EAL.

High-volume pre-dilution on-line hemodiafiltration is the adequate blood purification method from the viewpoint of amino acid nutrition

BackgroundWe compared amino acid leakage among high-volume pre-dilution on-line hemodiafiltration (Pre O-HDF), hemodialysis (HD), and post-dilution on-line hemodiafiltration (Post O-HDF).Subjects and methodsThe subjects were 9 patients. For HD, the total dialysate flow rate was established as 500 mL/min. For high-volume Pre O-HDF, it was established as 600 mL/min, under a replacement fluid volume of 90 L. For Post O-HDF, it was established as 600 mL/min, under a replacement fluid volume of 10 L. In both procedures, the duration of treatment was 4 h, and the blood flow volume was 200 mL/min. We compared the leakages of total amino acid, non-essential amino acid, and essential amino acid, clear spaces (CSs), β2-microglobulin (β2-MG) reduction rate, Kt/V for urea, and albumin leakage among the three procedures.ResultsAmino acid leakages after high-volume Pre O-HDF were significantly lower than HD and Post O-HDF. The CSs after high-volume Pre O-HDF were significantly lower than Post O-HDF. The β2-MG reduction rate after high-volume Pre O-HDF was significantly lower than Post O-HDF. The Kt/V for urea was not significantly different. Albumin leakages were below the detection limit (< 1 g) in the three procedures.ConclusionUnder the treatment conditions we performed this time, high-volume Pre O-HDF reduces amino acid leakage in comparison with HD and Post O-HDF. High-volume Pre O-HDF is a therapeutic mode that suppresses amino acid leakage.

Water-Soluble Vitamins and Trace Elements Losses during On-Line Hemodiafiltration.

Maintenance hemodialysis induces water-soluble vitamins and trace elements losses, which is why recommendations regarding potential supplementation were provided, but mainly based on conventional hemodialysis. This study′s aim was to measure the water–soluble vitamins and trace element losses during one on-line post-dilution hemodiafiltration (HDF) session. Thirty-nine patients under maintenance HDF were enrolled. We used the Theraflux® sampler (Theradial Corp., Orvault, France) to analyze the full session dialysate mass transfer. Blood and dialysate samples were collected before and after one HDF session to measure B1, B2, B6, B9, B12, C vitamins, zinc, and selenium concentrations. Values significantly decreased for B1 (20.2%), B2 (13%), B6 (25.4%), B9 (32.6%), C (66.6%) and selenium (6.7%). No significant differences were found for vitamin B12 and zinc. The dialysate losses per session were 1.12 ± 0.88 mg for vitamin B1, 0.28 ± 0.30 mg for B2, 0.33 ± 0.09 mg for B6, 0.3 ± 0.18 mg for B9, 147.5 ± 145.50 mg for C and 25.75 ± 6.91 mg for zinc. Vitamin B12 and selenium were under detection values. In conclusion, during a standard 4hr-HDF session, we found important losses for vitamin B1, B6, B9, C and zinc, suggesting the need for regular monitoring of plasma levels and systematic supplementation of these compounds.

MO889: High Flux Dialyzer 2.6 M2 is Promising for Free Light Chains Removal in High Flux Hemodialysis and Hemodiafiltration

Abstract BACKGROUND AND AIMS Immunoglobulin light chains are classified as middle molecule uremic toxins and its removal through effective dialyzer is needed with less albumin loss. This study assessed the free light chains removal using dialyzer surface area (SA) 2.6m2 in high flux dialysis (HD) versus hemodiafiltration (HDF) and its relation to cumulative albumin loss. METHOD A cross-over study included 25 patients who underwent hemodialysis using dialyzer surface area 2.6 m2 in high flux HD followed by online post-dilution hemodiafiltration with washout period 2 weeks using high flux dialyzers (max 2.0 m2 SA). All patients were subjected to single session measurement of dialysate albumin every hour and pre-post dialysis Free light chains (FLC) kappa and Lambda by ELISA. RESULTS Dialyzer (SA) 2.6m2 showed significant reduction in post-dialysis kappa and lambda in comparison to pre-dialysis level in high flux hemodialysis and hemodiafiltration (P &amp;lt; 0.001). HDF showed higher kappa and lambda FLC reduction ratio (45.16 ± 6.53 ng/mL), (28.68 ± 4.36 ng/mL), respectively compared with high flux HD (29.52 ± 6.38 ng/mL), (19.48 ± 1.96 ng/mL), respectively (P &amp;lt; 0.001). HDF/HD fold change of kappa and lamda were (1.56 ± 0.23) and (1.48 ± 0.26), respectively. Patients on HDF dialysis had significant total albumin loss in dialysate [median (IQR) 2.47 (1.16) gm/dL] compared with high flux dialysis [median (IQR) 0.65 (0.64) gm/dL] with (P &amp;lt; 0.001). Maximum albumin loss in patients on HDF was in the first hour [median (IQR) 1.22 (0.59)] gm/dL with lower albumin loss in the next hours reaching median {0.17 (0.15) gm/dL} in the fourth hour. Trans-membrane pressure was positively correlated with total albumin loss in high flux hemodialysis and hemodiafiltration (r 0.443, p 0.027, r 0.745, P = 0.001), respectively. CONCLUSION High flux dialyzer 2.6 m2 (SA) is effective for free light chains removal especially with online post-dilution hemodiafiltration with acceptable albumin loss.

MO661: Elimination of Middle and Large Uraemic Toxins in Short Daily Home Haemodialysis with Low Dialysate Volume: A Randomized Crossover Clinical Trial

Abstract BACKGROUND AND AIMS Portable haemodialysis (HD) systems with a low dialysate flow rate in a short frequent schedule have become an attractive option for patients on home HD (HHD). Although these systems have been demonstrated to be effective for removing low weight molecular uraemic toxins, there are few data on their removal ability of higher molecular weight toxins. This study assessed the uraemic toxin removal ability of the portable Physidia S3 Monitor in a short, frequent, 5 days/week, low-dialysate flux HHD versus 3 days/week, in centre online haemodiafiltration (OL-HDF). METHOD In an open, randomized, cross-over, single-centre, controlled, prospective study, 40 adult chronic HD patients were treated by a 2.5-h low flux dialysate HD session or a 4-h post-dilution OL-HDF. All other dialysis parameters including dialyzer (polysulfone high-flux dialyzer NS 1.8, Toray®) were kept constant in both the study arms. The weekly reduction rate (RR) and the weekly eliminated mass into dialysate (EM) of urea, creatinine, phosphate, β2-microglobulin, kappa (κFLC) and lambda (λFLC) free light chains and albumin, were intra-individually compared for the two dialysis types with linear mixed models. RESULTS There were no significant differences in the RR for urea, phosphate, κFLC and albumin, whereas the weekly RRs for creatinine and β2-microglobulin were significantly higher with the Physidia S3 system than those obtained with OL-HDF (Table). Only the λFLC RR was significantly higher with OL-HDF. Similar results were observed when weekly EMs were compared (data not shown). CONCLUSION This study demonstrates that treating patients with low flow dialysate HHD in a short frequent schedule with Physidia S3 system, instead of 3 days/week, in-centre OL-HDF, significantly increases the weekly elimination of β2-microglobulin, enabling an adequate clearance of small and large uraemic toxins.

Comparative Effectiveness between Expanded Hemodialysis (Hemodialysis Using a Medium Cut-Off Dialyzer) and Mixed-Dilution Online Hemodiafiltration Using a High-Flux Dialyzer in Removing Middle-Molecule Uremic Toxins

Introduction: Expanded hemodialysis (HD using a medium cut-off dialyzer [HD + MCO]) provides comparable or better removal of various uremic toxins, particularly large middle-molecule uremic toxins, than post-dilution online hemodiafiltration (olHDF). Uremic toxin-removing effectiveness between HD + MCO and mixed-dilution olHDF, one of the currently most efficient olHDF modalities, has not been assessed. Method: This randomized controlled trial was conducted in 14 prevalent thrice-a-week HD patients with blood flow rate above 400 mL/min. The patients were randomized into two sequences of 2-week treatment periods of HD + MCO and later mixed-dilution olHDF or vice versa. The reduction ratio (RR) values of small-molecule as well as middle-molecule uremic toxins and protein-bound uremic toxins were measured at baseline and at the end of the treatment. Results: When compared with mixed-dilution olHDF, HD + MCO provided slightly lower β₂M RR, but the value was still higher than 75%; showed similar κFLC RR, IS RR, and URR; and yielded significantly higher RR values of α₁M (p < 0.001) and λFLC (p < 0.001). Despite higher albumin loss in HD + MCO, the serum albumin levels at the end of the study were comparable between both groups. Conclusion: Expanded HD (HD + MCO) provided similar effectiveness in removing various uremic toxins and could exhibit greater removal of large middle-molecule uremic toxins, such as α₁M and λFLC. Expanded HD can be used as an effective alternative option for mixed-dilution olHDF.