Search

Hemodialysis (HD), from the clinical perspective, involves the HD machine, blood lines or tubing, and a dialyzer that mimics the physiologic action of the kidneys to clear the blood of wastes or by-products. A literature review was performed to identify preventative measures of coagulation during HD treatment. EBSCOhost, Academic Search Premier, MEDLINE, and PubMed were used. Seventy-nine (79) related articles were found. Sixty-one (61) were excluded, and 18 were included in the study. Low-dose/unfractionated heparin, low molecular weight heparin(s), airless tubing system, specially formulated dialyzers, continuous saline flushes, and contact activation inhibitor-AB023, combining heparin-coated dialyzers with intermittent saline flushes, are useful preventive measures. It is important to evaluate the individual needs of each patient in making decisions regarding treatment. [ABSTRACT FROM AUTHOR]

BACKGROUND: The Hollow Fiber Infection Model (HFIM) is established for studying pharmacodynamic (PD) effects considering pharmacokinetic (PK) profiles. The core is a cartridge with bacteria retained outside hollow fibers, which nutrients, metabolites and anti-infectives can selectively permeate. However, commercial cartridges with high-flux polysulfone (PS) fibers are expensive (up to 1000 €), limiting academic research use. Hemodialyzers for renal replacement therapy are similarly constructed and within an affordable price range (15-30 €). AIM: Comparison of cost-effective renal replacement therapy PS hemodialyzer with commercial HFIM cartridges. METHODS: HFIM experiments were conducted in a commercial cartridge (FiberCell Systems C2011) and a PS hemodialyzer (Fresenius Medical Care FX paed) using a clinical E. coli treated with Ceftazidim/Avibactam (CZA) or Fosfomycin (FOS). For CZA + FOS scenarios, one commercial cartridge and three hemodialyzers were connected in parallel to assure equal conditions. RESULTS: Hemodialyzers proved suitable for HFIM experiments. PD results from both systems in high and low-dose scenarios were in concordance. Notably, in two regimens (CZA 0.06/0.015 g + FOS 0.125 g and CZA 0.5/0.125 g), regrowth was observed in the commercial cartridge but not in the FX paed hemodialyzer. Conversely, FOS 4 g showed regrowth in the FX paed hemodialyzer but not in the commercial cartridge. PD effects in FX paed hemodialyzers were reproducible. CONCLUSION: FX paed hemodialyzers demonstrated reproducibility in PD results, with some discrepancy from commercial cartridges. More research to explore the causes for the differences is warranted.

Abstract Background In Japan dialyzers are classified as type I, II, III, IV, or V on the basis of the β 2-microglobulin clearance. In 2023, Type V dialyzers were defined as super high-flux membrane dialyzers. Herein, we investigate the association between dialyzer type and mortality. Methods A cohort study was conducted using the Japanese Society for Dialysis Therapy Renal Data Registry database from 31 December 2017, to 31 December 2019. We enrolled 181,879 patients on hemodialysis who were divided into type I–V groups per the Japanese classification. We assessed the associations of each group with 2-year all-cause mortality using Cox proportional hazard models. Furthermore, propensity score matching analysis was performed. Results By the end of 2019, 34,196 patients (18.8%) had died. The hazard ratio (95% confidence interval) was significantly higher in the type I (1.25 [1.12–1.39]), type II (1.21 [1.13–1.31]), and type III (1.07 [1.02–1.13]) groups and significantly lower in the type V group (0.86 [0.80–0.92] P

Abstract Background Hemodialyzers should efficiently eliminate small and middle molecular uremic toxins and possess exceptional hemocompatibility to improve well-being of patients with end-stage kidney disease. However, performance and hemocompatibility get compromised during treatment due to adsorption of plasma proteins to the dialyzer membrane. Increased membrane hydrophilicity reduces protein adsorption to the membrane and was implemented in the novel FX CorAL dialyzer. The present randomized controlled trial compares performance and hemocompatibility profiles of the FX CorAL dialyzer to other commonly used dialyzers applied in hemodiafiltration treatments. Methods This prospective, open, controlled, multicentric, interventional, crossover study randomized stable patients on post-dilution online hemodiafiltration (HDF) to FX CorAL 600, FX CorDiax 600 (both Fresenius Medical Care) and xevonta Hi 15 (B. Braun) each for 4 weeks. Primary outcome was β2-microglobulin removal rate (β2-m RR). Non-inferiority and superiority of FX CorAL versus comparators were tested. Secondary endpoints were RR and/or clearance of small and middle molecules, and intra- and interdialytic profiles of hemocompatibility markers, with regards to complement activation, cell activation/inflammation, platelet activation and oxidative stress. Further endpoints were patient reported outcomes (PROs) and clinical safety. Results 82 patients were included and 76 analyzed as intention-to-treat (ITT) population. FX CorAL showed the highest β2-m RR (76.28%), followed by FX CorDiax (75.69%) and xevonta (74.48%). Non-inferiority to both comparators and superiority to xevonta were statistically significant. Secondary endpoints related to middle molecules corroborated these results; performance for small molecules was comparable between dialyzers. Regarding intradialytic hemocompatibility, FX CorAL showed lower complement, white blood cell, and platelet activation. There were no differences in interdialytic hemocompatibility, PROs, or clinical safety. Conclusions The novel FX CorAL with increased membrane hydrophilicity showed strong performance and a favorable hemocompatibility profile as compared to other commonly used dialyzers in clinical practice. Further long-term investigations should examine whether the benefits of FX CorAL will translate into improved cardiovascular and mortality endpoints. Trial registration eMPORA III registration on 19/01/2021 at ClinicalTrials.gov (NCT04714281).

Background: Hemodialyzers should efficiently eliminate small and middle molecular uremic toxins and possess exceptional hemocompatibility to improve well-being of patients with end-stage kidney disease. However, performance and hemocompatibility get compromised during treatment due to adsorption of plasma proteins to the dialyzer membrane. Increased membrane hydrophilicity reduces protein adsorption to the membrane and was implemented in the novel FX CorAL dialyzer. The present randomized controlled trial compares performance and hemocompatibility profiles of the FX CorAL dialyzer to other commonly used dialyzers applied in hemodiafiltration treatments. Methods: This prospective, open, controlled, multicentric, interventional, crossover study randomized stable patients on post-dilution online hemodiafiltration (HDF) to FX CorAL 600, FX CorDiax 600 (both Fresenius Medical Care) and xevonta Hi 15 (B. Braun) each for 4 weeks. Primary outcome was β2-microglobulin removal rate (β2-m RR). Non-inferiority and superiority of FX CorAL versus comparators were tested. Secondary endpoints were RR and/or clearance of small and middle molecules, and intra- and interdialytic profiles of hemocompatibility markers, with regards to complement activation, cell activation/inflammation, platelet activation and oxidative stress. Further endpoints were patient reported outcomes (PROs) and clinical safety. Results: 82 patients were included and 76 analyzed as intention-to-treat (ITT) population. FX CorAL showed the highest β2-m RR (76.28%), followed by FX CorDiax (75.69%) and xevonta (74.48%). Non-inferiority to both comparators and superiority to xevonta were statistically significant. Secondary endpoints related to middle molecules corroborated these results; performance for small molecules was comparable between dialyzers. Regarding intradialytic hemocompatibility, FX CorAL showed lower complement, white blood cell, and platelet activation. There were no differences in interdialytic hemocompatibility, PROs, or clinical safety. Conclusions: The novel FX CorAL with increased membrane hydrophilicity showed strong performance and a favorable hemocompatibility profile as compared to other commonly used dialyzers in clinical practice. Further long-term investigations should examine whether the benefits of FX CorAL will translate into improved cardiovascular and mortality endpoints. Trial registration: eMPORA III registration on 19/01/2021 at ClinicalTrials.gov (NCT04714281). [ABSTRACT FROM AUTHOR]

Ultrasonic plastic welding is widely used in the bonding process of medical device accessories. In this paper, a thermo-force indirect coupling finite element analysis model was established in the ultrasonic plastic welding process between the blood cap and the shell of polypropylene (PP) dialyzer. The temperature field distribution between the blood cap and the shell was simulated and analyzed by using finite element analysis software, and the influence of welding process parameters on the temperature field was studied. The results show that: by changing the ultrasonic amplitude parameters, welding time parameters, initial pressure, etc., the longer the ultrasonic welding time, the temperature of the welding area will increase. In order to ensure the quality of the dialyzer, it should be controlled within 0.8-1 seconds. The increase of ultrasonic amplitude will make the welding temperature continue to rise, and in order to avoid poor welding, the amplitude should not exceed 120 μm. The initial pressure has little effect on the temperature field. [ABSTRACT FROM AUTHOR]

Hypoalbuminemia results when compensatory mechanisms are unable to keep pace with derangements in catabolism/loss and/or decreased synthesis of albumin. Across many disease states, including chronic kidney disease (CKD), hypoalbuminemia is a well-established, independent risk factor for adverse outcomes, including mortality. In the setting of CKD, reduced serum albumin concentrations are often a manifestation of protein-energy wasting, a state of metabolic and nutritional alterations resulting in reduced protein and energy stores. The progression of CKD to kidney failure and the initiation of maintenance hemodialysis (HD) further predisposes an already at-risk population toward hypoalbuminemia such that approximately 60% of HD patients have albumin concentrations

BackgroundRecommendations and practice patterns for heparin dosing during hemodialysis show substantial heterogeneity and are scantly supported by evidence. This study assessed the variability in unfractionated heparin (UFH) dosing during hemodialysis and its clinical and biological anticoagulatory effects, and identified explanatory factors of heparin dosing.MethodsCross-sectional study assessing UFH dosing, coagulation tests – activated partial thromboplastin time (aPTT) and activated clotting time (ACT) before dialysis start, 1 h after start and at treatment end (4 h) – and measurement of residual blood compartment volume of used dialyzers.Results101 patients, 58% male, with a median dialysis vintage of 33 (6–71) months received hemodialysis using a total UFH dose of 9,306 ± 4,079 (range 3,000–23,050) IU/session. Use of a dialysis catheter (n = 56, 55%) was associated with a 1.4 times higher UFH dose (p < 0.001) irrespective of prior access function. aPTT increased significantly more than ACT both 1 h and 4 h after dialysis start, independent of the dialysis access used. 53% of patients with catheter access and ACT ratio < 1.5, 1 h after dialysis start had simultaneous aPTT ratios > 2.5. Similar findings were present at 1 h for patients with AVF/AVG and at dialysis end for catheter use. No clinically significant clotting of the extracorporeal circuit was noted during the studied sessions. Dialyzer’s blood compartment volume was reduced with a median of 9% (6–20%) without significant effect of UFH dose, aPTT or ACT measurements and vascular access type.ConclusionUFH dose adaptations based on ACT measurements frequently result in excessive anticoagulation according to aPTT results. Higher doses of UFH are used in patients with hemodialysis catheters without evidence that this reduces dialyzer clotting.

Dialyzer clearance (K) for hemodialysis is usually predicted from the mass transfer area product (K 0 A) provided in manufacturer data sheets without accounting for elevated feed-viscosity when treating blood. The boundary layer model for mass transport across hollow fiber membranes, however, predicts an increase in mass transfer resistance (1/ K 0) and a decrease in K with increasing feed-viscosity. The effect of increased feed-side viscosity relative to baseline crystalloid viscosity on small solute K and 1/ K 0 was therefore examined in commercial high- (HF) and low-flux (LF) dialyzers in lab-bench studies using standard dialysis equipment in the normal operating range. Homogeneous colloid solutions and bovine plasma were used to simulate the range of relative viscosities (η rel) and oncotic pressures expected under in-vivo conditions. Internal filtration (IF) was quantified by a mathematical model to obtain diffusive transport characteristics (K ', 1/ K 0 ′). An up to 5-fold increase in η rel caused a small increase in K and a small decrease in 1/ K 0 in HF, but not in LF dialyzers. After correction for a small convective contribution by IF, K ' and 1/ K 0 ′ remained constant in both LF and HF dialyzers. Diffusive transport characteristics of commercial HF and LF dialyzers are independent of variable feed-side viscosity. This suggests an insignificant contribution of the feed-side boundary layer resistance in dialyzers optimized for operation in hemodialysis. Increasing the feed-side viscosity, however, increases the convective component of dialyzer solute transport because of IF. Diffusive dialyzer clearance predicted from the dialyzer K 0 A is independent of elevated feed-viscosity. [ABSTRACT FROM AUTHOR]

Background: Toxin removal capacity (i.e., performance) of a dialyzer is not constant but diminishes during treatment, as the adsorption of proteins to the membrane provides an additional barrier to uremic solutes. We investigated time‐resolving molecular weight retention changes among synthetic high‐flux dialyzers and compared the results with recent data from a randomized controlled trial. Methods: In plasma recirculation experiments over 240 min, sieving coefficients (SC) for β2‐microglobulin, myoglobin, and albumin were determined for the FX CorAL (Fresenius Medical Care), ELISIO (Nipro), and xevonta (B. Braun). Molecular weight retention (MWR) curves were generated and the shifts over 120 min were characterized. Effective pore radius was determined, and the predicted albumin loss was compared with clinical data. Results: SC decreased over time for all dialyzers (mean relative decrease across all dialyzers: β2‐microglobulin: 8.0% (120 min); myoglobin: 56.6% (240 min); albumin: 94.1% (240 min)). FX CorAL (7.3%, 52.6% and 91.1%) and ELISIO (7.7%, 51.0%, and 93.8%) showed a lower decrease than xevonta (9.0%, 66.2%, and 97.4%). For all dialyzers, MWR curves shifted toward lower molecular weight, with the lowest shift for FX CorAL (by 0.23 nm at SC50%, 120 min) and highest for xevonta (0.50 nm). FX CorAL had the highest slope over time and the smallest decrease in the effective pore radius (2 min: 2.31 nm, 120 min: 2.08 nm). Predicted albumin loss over 4 h was highest for xevonta (609.3 mg) and comparable between ELISIO (283.6 mg) and FX CorAL (313.3 mg). Conclusions: Substantial differences in the temporal performance profile of dialyzers exist. The present approach allows the characterization of dialyzer permeability changes over time using standard, clinically relevant protein markers. [ABSTRACT FROM AUTHOR]

Anticoagulation therapy is widely used to reduce clotting during hemodialysis (HD), but may cause adverse effects in end‐stage kidney disease patients. A new hemodialyzer with a membrane modified by surface modifying molecule was developed to improve hemocompatibility that aimed to reduce the need for anticoagulation during dialysis treatments. We compared membrane surface characteristics and in vitro hemocompatibility of the new hemodialyzer to the standard polysulfone (PSF) hemodialyzer membrane. Scanning electron microscopy, contact angle measurement (68° ± 3° test vs. 41.6° ± 6° control), and X‐ray photoelectron spectrometry measurement for fluorine atomic % (7.4% ± 0.4% test vs. not detectable control), showed that the membrane surface was modified with surface modifying macromolecule (SMM1) but maintained membrane structure and surface hydrophilicity. Zeta potential of the blood‐contacting surface showed that the absolute surface charge was reduced at neutral pH (−3.3 mV ± 1.1 mV test vs. −15.6 mV ± 1.0 mV control). Platelet count reduction was significantly less for the SMM1‐modified dialyzer (40.88% ± 21.89%) compared to the standard PSF dialyzer (62.62% ± 34.13%), along with Platelet Factor 4 (1824.10 ng/ml ± 436.26 ng/ml test vs. 2479.00 ng/ml ± 852.96 ng/ml control). These studies demonstrate the successful incorporation of SMM1 into the new hemodialyzer with the expected results. Our in vitro experiments indicate that the SMM1‐modified hemodialyzers could improve hemocompatibility compared to standard PSF hemodialyzers and have the potential to minimize the patient's anticoagulant requirements during HD. Additional research with SMM1 additives incorporated into the entire dialysis circuit and use in a clinical settings are required to confirm these promising findings. [ABSTRACT FROM AUTHOR]

Introduction. Accumulation of middle molecular weight uremic toxins causes various complications in chronic hemodialysis (HD) patients. Postdilution online hemodiafiltration (OL-HDF) efficiently removes these molecules. This study aimed to assess the effectiveness of three different dialysis membranes in removing β2- microglobulin (β2m) within a single session of postdilution OL-HDF. Method. A prospective single-center study was carried out in 30 patients (23 males and seven females, average age 54.87 ± 11.66 years, time on dialysis 4.95 ± 5.4 years) on maintenance HD. Each patient was followed for three consecutive weeks on OL-HDF with three different dialyzers: DiacapPro 19H, FX CorDiax 800, and Elisio 21H, randomly switched weekly. The reduction ratios (RR) of β2m and albumin were compared individually. The results were analyzed with the Kolmogorov–Smirnov test, ANOVA, and the Kruskal–Wallis test. Results. The average convective volume for all patients was 21.38 ± 2.97 L/session. β2-m RR was 70.86 ± 6.87%, 74.69 ± 6.51%, and 70.04 ± 9.37% with Diacap Pro 19H, FX CorDiax 800 and Elisio 21H membrane, respectively (p = 0.054). Albumin RR was 6.20 ± 2.12% with Diacap Pro 19H membrane, 6.01 ± 2.97% with FX CorDiax 800 membrane, and 6.46 ± 2.91% with Elisio 21H membrane (p = 0.812). Albumin loss was < 4 g/dialysis treatment for all membranes. Conclusion. All investigated membranes effectively remove β2-m in postdilution OL-HDF with a tolerable albumin loss. The highest β2-m RR was determined for FX CorDiax 800 membrane, but with no statistically significant difference.

Kamyar Kalantar-Zadeh,1– 3 Linda H Ficociello,4 Jennifer Bazzanella,5 Claudy Mullon,4 Michael S Anger4 1Division of Nephrology, Hypertension and Kidney Transplantation, University of California, Irvine, School of Medicine, Orange, CA, USA; 2Department of Epidemiology, University of California, Los Angeles (UCLA), Los Angeles, CA, USA; 3Los Angeles Biomedical Research Institute at Harbor–UCLA, Torrance, CA, USA; 4Fresenius Medical Care Renal Therapies Group, Waltham, MA, USA; 5Fresenius Kidney Care, Madison, WI, USACorrespondence: Kamyar Kalantar-ZadehDivision of Nephrology, Hypertension and Kidney Transplantation, University of California, Irvine Medical Center, 101 the City Drive South, Orange, CA 92868-3217, USATel +1-714-456-5142Fax +1-714-456-6034Email kkz@uci.eduAbstract: Hypoalbuminemia results when compensatory mechanisms are unable to keep pace with derangements in catabolism/loss and/or decreased synthesis of albumin. Across many disease states, including chronic kidney disease (CKD), hypoalbuminemia is a well-established, independent risk factor for adverse outcomes, including mortality. In the setting of CKD, reduced serum albumin concentrations are often a manifestation of protein-energy wasting, a state of metabolic and nutritional alterations resulting in reduced protein and energy stores. The progression of CKD to kidney failure and the initiation of maintenance hemodialysis (HD) further predisposes an already at-risk population toward hypoalbuminemia such that approximately 60% of HD patients have albumin concentrations < 4.0 g/dl. Albumin loss into the dialysate through the dialyzer appears to be a potentially modifiable cause of hypoalbuminemia in some patients. A group of newer dialyzers for maintenance HD—sometimes termed protein-leaking or medium cut-off membranes—aim to improve clearance of middle molecules (vs high flux dialyzers) but are associated with increased albumin losses. In this article, we will examine the impact of dialyzer selection on albumin losses during conventional HD, including the clinical relevance of such losses on serum albumin levels. Data on the clinical relevance of albumin losses during dialysis and current gaps in the evidence base are also discussed.Keywords: dialysis membrane, dialyzer, nutrition, hemodialysis, protein-energy wasting

Advancing the knowledge of surfaces and protein interactions is paramount to development of non‐fouling membranes for many applications, particularly continuous blood flow wearable and implantable devices. Here, highly controlled experiments to understand the effect of graphene oxide (GO) surface properties on its protein adsorption are presented. A newly developed self‐assembly process is implemented to build a GO membrane with an atomically smooth surface to eliminate the effect of surface roughness on protein adsorption. The GO oxidation level is varied to change the overall membrane hydrophilicity while the nanoplatelets size and edge area is maintained constant. The fouling characteristics of the membrane are examined through scanning electron microscope imaging and long‐term water flux measurements. These measurements unambiguously prove that proteins are primarily adsorbed on the basal areas of nanoplatelets, on the graphitic regions, away from the nanoplatelets edges. As a result, while decreasing the oxidation level reduced the overall surface hydrophilicity leading to more protein adsorption, the membrane mass flux is minimally impacted. Studies on a polymer membrane under similar conditions show expansion of protein agglomerates over time leading to formation of large biofilm domains, while the GO nanoplatelets edges function as a barrier to formation of an expansive biofilm. [ABSTRACT FROM AUTHOR]

We developed a new hybrid material resulting from an innovative supramolecular tripartite association between an ionic liquid covalently immobilized on primary β-cyclodextrins rim and an anionic water-soluble polymer. Two hydrophilic ternary complexes based on native and permethylated β-cyclodextrins substituted with an ionic liquid and immobilized on poly(styrene sulfonate) (CD-IL+PSS− and CD(OMe)IL+PSS−) were obtained by simple dialysis with a cyclodextrin maximal grafting rate of 25% and 20% on the polymer, respectively. These polyelectrolytes are based on electrostatic interactions between the opposite charges of the imidazolium cation of the ionic liquid and the poly(styrene sulfonate) anion. The inclusion properties of the free cavities of the cyclodextrins and the synergic effect of the polymeric matrix were studied with three reference guests such as phenolphthalein, p-nitrophenol, and 2-anilinonaphthalene-6-sulfonic acid using UV-visible, fluorescent, and NMR spectroscopies. The support has been applied successfully in dialysis device to extract and concentrated aromatic model molecule. This simple and flexible synthetic strategy opens the way to new hybrid materials useful for fast and low-cost ecofriendly extraction techniques relevant for green analytical chemistry. [ABSTRACT FROM AUTHOR]

We evaluated the influences of the priming process (washing with saline), saline circulation conditions, and saline incubation on the in vitro elution of substances from three types of polysulfone (PSu) membrane dialyzers sterilized using gamma irradiation [NV-15X (Toray Industries, Inc.)], autoclaving [RENAK-PS1.6 (Kawasumi Laboratories, Inc.)], or in-line steam [FX-140J (Fresenius Medical Care)] methods as well as a non-PSu cellulose triacetate (CTA) membrane dialyzer [FB-150U(NIPRO)]. The effect of priming was evaluated by circulating 1000 mL of saline through the dialyzers at a rate of 100 mL/min and measuring the elution level of the substances by determining their ultraviolet (UV) absorption at 220 nm using spectrophotometry. All the tested dialyzers showed that the elution of the substances decreased as per the order of sample collection. Primed dialyzers were used in the subsequent experiments. Circulating saline through the primed membrane dialyzers at a flow rate of 100 mL/min caused time-dependent elution of substances from all the tested dialyzers; increasing the flow rate to 200 mL/min did not have a significant effect on the time-dependence or elution amount at each time point (0–8 h). The elution was also evaluated after incubating the membrane dialyzers with saline for 24 h. A co-submitted article (Sato et al., 2021) detailed the preparation of the identical experimental circuits, as well as the influences of saline washing, saline circulation conditions, and saline incubation on the elution of the hydrophilic agent polyvinylpyrrolidone (PVP) from each dialyzer using the Müller method, which can enable specific detection of PVP (Müller, 1968). The relative elution levels of PVP among the dialyzers and the experimental conditions were different from those of substances determined using UV (220 nm) absorption. Our data might be used for further development of experiments for identifying non-PVP substances eluted from dialyzers by providing information regarding the conditions of the elutions and types of dialyzers from which they are eluted.

Background: By inhibiting the adsorption of protein and platelets, surface-modifying macromolecules (SMMs) may improve the hemocompatibility of hemodialyzers. This trial aims to assess the performance and safety of a novel dialyzer with a fluorinated polyurethane SMM, Endexo™. Methods: This prospective, sequential, multicenter, open-label study (NCT03536663) was designed to meet regulatory requirements for clinical testing of new hemodialyzers, including assessment of the in vivo ultrafiltration coefficient (Kuf). Adults prescribed thrice-weekly hemodialysis were eligible for enrollment. After completing 12 hemodialysis sessions with an Optiflux® F160NR dialyzer, patients received 38 sessions with the dialyzer with Endexo. Evaluated parameters included the in vivo Kuf of the dialyzer with Endexo extent of removal of urea, albumin, and β2-microglobulin (β2M), as well as complement activation. Results: Twenty-three patients received 268 hemodialysis treatments during the Optiflux period, and 18 patients received 664 hemodialysis treatments during the Endexo period. Three serious adverse events were reported, and none of them were considered device related. No overt complement activation was observed with either dialyzer. Both dialyzers were associated with comparable mean increases in serum albumin levels from pre- to posthemodialysis (Optiflux: 7.9%; Endexo: 8.0%). These increases can be viewed in the context of a mean increase in hemoglobin of approximately 5% and a mean ultrafiltration volume removed of approximately 2.2 L. The corrected mean β2M removal rate was 47% higher during the Endexo period (67.73%). Mean treatment times (208 vs. 205 min), blood flow rates (447.7 vs. 447.5 mL/min), dialysate flow rates (698.5 vs. 698.0 mL/min), urea reduction ratio (82 vs. 81%), and spKt/V (2.1 vs. 1.9) were comparable for the Endexo and Optiflux periods, respectively. The mean (SD) Kuf was 15.85 (10.33) mL/h/mm Hg during the first use of the dialyzer with Endexo (primary endpoint) and 16.36 (9.92) mL/h/mm Hg across the Endexo period. Conclusions: The safety of the novel dialyzer with Endexo was generally comparable to the Optiflux dialyzer, while exhibiting a higher β2M removal rate. [ABSTRACT FROM AUTHOR]

Toray has created a new generation of dialyzers, the polysulphone (TS) UL series, and polymethylmethacrylate (PMMA) NF‐U series, which offer enhanced efficacy over the previous TS‐S series and NF‐H series. The aim of this study was to evaluate the safety and efficacy of these dialyzer series versus contrasted expanded hemodialysis (HDx) and postdilution hemodiafiltration (HDF). We conducted a prospective study in 12 patients. Each patient underwent six dialysis sessions: FX80 Cordiax in HD, Toraysulfone TS‐1.8 UL in HD, Theranova 400 in HDx, polymethylmethacrylate (PMMA) NF‐2.1 U in HDF, Toraysulfone TS‐2.1 UL in HDF, and FX80 Cordiax in HDF. The removal ratios (RRs) of urea, creatinine, ß2‐microglobulin, myoglobin, prolactin, α1‐microglobulin, α1‐acid glycoprotein, and albumin were compared intraindividually. Dialysate albumin loss was also measured. The RRs for β2‐microglobulin, myoglobin, prolactin, α1‐microglobulin, and α1‐acid glycoprotein were higher with the TS‐2.1 UL and FX80 Cordiax dialyzers in HDF than those obtained with HD treatments and NF‐2.1 U in HDF. The β2‐microglobulin, myoglobin, and prolactin RRs were also higher with HDx than those obtained with HD treatments. The myoglobin and prolactin RRs were higher with TS‐1.8 UL in HD than those obtained with helixone dialyzers in HD. Dialysate albumin loss was less than 3 g in all situations except in TS‐2.1 UL in HDF. The highest global removal score values were obtained with the TS‐2.1 UL and helixone dialyzers in HDF. Significant differences were found between all study situations. In conclusion, the new generation dialyzers, Toraysulfone TS Series UL and PMMA NF‐U series, show excellent behaviour and tolerance in HD and HDF, representing an upgrade versus their predecessor series. The higher permeability of the TS UL series has been proven with higher efficiency in HD and maximum performance in HDF. The new PMMA NF‐U series allows the use of HDF with good efficiency and complete safety. [ABSTRACT FROM AUTHOR]

Bacteremia in dialysis patients is a major risk factor of mortality. The aim of this study was to assess the effectiveness of dialysis with high-flux versus low-flux dialyzer regarding risk of bacteremia in dialysis patients. This was a retrospective cohort study that included dialysis patients who underwent dialysis therapy at old dialysis center where old low-flux dialyzers were used and the new dialysis center where high-flux dialyzers were used. The rate of positive culture was more in high-flux group (37.0%) compared to low-flux group (24.5%), although the difference was not statistically significant (P = 0.13). The vascular access was mostly permanent catheter in high-flux group compared to low-flux group (48.9% vs. 28.6%, respectively; P = 0.06), while arteriovenous (AV) fistula was more prominent in low-flux group compared to high-flux group (65.3% vs. 47.8%, respectively; P = 0.06). This was reflected in the type of bacteria, which was mostly from Gram-positive family (Staphylococcus). The results showed higher risk of bacteremia in high-flux group as compared to low-flux group; however, permanent catheters were more prominent in high-flux group.

BackgroundAlthough much is known about the effect of chronic kidney failure and dialysis on the composition of solutes in plasma, little is known about their impact on the composition of gaseous compounds in exhaled breath. This study was designed to explore the effect of uremia and the hemodialysis (HD) procedure on the composition of exhaled breath. Breath samples were collected from 10 dialysis patients immediately before, during, and after a dialysis session. To determine the potential introduction of gaseous compounds from dialysis components, gasses emitted from dialyzers, tubing set, dialysate, and water supplies were collected.Study designProspective cohort study.Participants10 HD patients and 10 age-matched healthy individuals.PredictorPredictors include the dialyzers, tubing set, dialysate, and water supplies before, during, and after dialysis.OutcomesChanges in the composition of exhaled breath.MeasurementsA 5-column/detector gas chromatography system was used to measure hydrocarbon, halocarbon, oxygenate, and alkyl nitrate compounds.ResultsConcentrations of 14 hydrocarbons and halocarbons in patients' breath rapidly increased after the onset of the HD treatment. All 14 compounds and 5 others not found in patients' breath were emitted from the dialyzers and tubing sets. Contrary to earlier reports, exhaled breath ethane concentrations in our dialysis patients were virtually unchanged during the HD treatment.LimitationsSingle-center study with a small sample size may limit the generalizability of the findings.ConclusionsThe study documented the release of several potentially toxic hydrocarbons and halocarbons to patients from the dialyzer and tubing sets during the HD procedure. Because long-term exposure to these compounds may contribute to the morbidity and mortality in dialysis population, this issue should be considered in the manufacturing of the new generation of dialyzers and dialysis tubing sets.

Purpose: This study aimed to use proteomics methods to investigate the changes in serum protein levels after high- and low-flux hemodialysis (HD). Methods: Before and after HD, serum samples were obtained from two selected patients who were treated with a Polyflux 140 H high-flux dialyzer and a Polyflux 14 L low-flux dialyzer during two continuous therapy sessions. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was performed to identify the proteins. Results: A total of 212 and 203 serum proteins were identified after high-flux and low-flux HD, respectively. After high-flux HD, 21 proteins increased, and 132 proteins decreased. After low-flux HD, 87 proteins increased, and 45 proteins decreased. High-flux HD led to a significantly greater reduction in protein levels than low-flux HD (0.73 ± 0.13 vs. 0.84 ± 0.18, p = .00). Among the increased and decreased proteins, the isoelectric point (pI) values mainly ranged from 5 to 7, and the molecular weights (Mws) were mostly smaller than 30 kDa. The serum proteins showed no difference in pI or Mw for high- and low-flux HD. Gene ontology (GO) analysis showed that the detected proteins were related to immune system processes and complement activation. Conclusions: Serum protein levels differentially changed after high- and low-flux HD. Long-term effects should be observed in future studies.

Background/Aims: A recent alert from Spanish health authorities warned of a higher incidence of reported hypersensitivity reactions to hemodialysis membranes with polysulfone, in the 2017 review of acute reactions to dialyzers found only published reports in the 21st century on polysulfone and its derivatives. The aim is to assess/evaluate the current incidence and characteristics of hypersensitivity reactions in hemodialysis patients. Methods: A retrospective multicentre study in 9 Spanish hospitals evaluated patients in whom a hypersensitivity reaction required a change in dialyzer membrane. Results: A total of 37 patients out of 1561 (2.37%) had hypersensitivity reactions and clinical, epidemiological and analytical data were available for 33 patients (2.11%). The membranes involved were polysulfone (n=23), polynephron (n=8), polyethersulfone (n=1) and polyacrylonitrile (n=1). This distribution reflected the frequency of use of membranes in the participating dialysis units. The reactions were described as type A in 18 cases and type B in 15 cases. There were no significant differences between the two types in clinical symptoms, the composition of the membrane involved, the method of sterilization, the season, or the time during the session in which they occurred. The most frequent symptom was dyspnea/breathlessness (64% of reactions). Eosinophilia was common (74%). 54% of the reactions occurred within the first 30 minutes of hemodialysis, 64% occurred during the first year of dialysis, and 54% required discontinuation of dialysis session. Cellulose triacetate was used as an alternative dialyzer in 78% of the cases. Conclusion: The incidence of hypersensitivity reactions was in the range found in reports from 20 years ago and is observed associated with synthetic membranes, not just polysulfones. Cellulose triacetate appears to be a good alternative for these patients.

Abstract Background Historically, cellulose-based materials have been used for manufacturing hemodialysis membranes and remain to date as the commonly used materials. Though cellulose triacetate (CTA) membrane originally has a homogeneous structure, recently, CTA membrane with asymmetric structure (ATA®) was developed. By a new spinning technology, irregularities or roughness in the inner surface of ATA have become less than those of the conventional CTA membrane. In this study, a comparison was made between CTA and ATA® membranes in order to evaluate the effect of physical structure of the membrane on the biocompatibility. Methods We compared the biocompatibility of the following two dialyzers with different triacetate membrane: FB-190UHβ with CTA, and FA-190F with ATA® (both from Nipro, Osaka, Japan). Heparin of 40 units/mL was put in a syringe, and test blood was collected from healthy volunteers. Then, the dialyzer and blood circuit were filled with the test blood. Subsequently, the blood was circulated by a roller pump at the rate of 200 mL/min. We measured the platelet counts, platelet factor 4 (PF4), β-thromboglobulin (β-TG), and CD41 and CD42b platelet surface markers at 30, 120, and 240 min. Results The average platelet counts at 30, 120, 240 min in CTA and ATA® were similar. The average β-TG and PF4 increased from 87.0 ± 49.0 ng/mL and 30.7 ± 17.3 ng/mL to 1198.5 ± 1017.2 ng/mL and 698.2 ± 574.6 ng/mL with CTA and to 774.3 ± 811.6 ng/mL and 509.0 ± 417.3 ng/mL with ATA®, respectively. The average expression of CD41 and CD42b decreased to 82.8 ± 9.7% and 80.1 ± 11.6% with CTA and 81.9 ± 14.3% and 80.2 ± 13.6% with ATA®, respectively. Conclusions Observed dialyzers showed less platelet activation as commercial products, and differences between CTA and ATA® were not significant in terms of PF4, β-TG, CD41, and CD42b.

The dialyzer is the core element of extracorporeal blood purification therapies where several processes take place depending on specific membrane characteristics. To date, the filter choice requires preliminary knowledge of all its characteristics as they cannot be easily deduced from the commercial trade name, hence the difficulty in identifying easily equivalent dialyzers and clearly comparing single‐filter characteristics. The choice of improper dialyzers for a specific treatment can determine a less‐effective blood purification and potentially harmful treatments. We aimed to propose a univocal and standardized alphanumeric string to summarize essential filter properties in the Dialyzer Identification Code (DIC). DIC clearly describes device characteristics and allows to compare different dialyzer performances without resorting to the technical data sheets. Therefore, the presence of the DIC on every device facilitates information retrieval on the dialyzer, its intended use, and can facilitate matching the dialysis modality to correct dialyzers achieving a personalized renal replacement therapy. The standard filter characteristics codification by the DIC may further optimize correct extracorporeal blood purification prescriptions and the use of equivalent filters from different providers avoiding treatment inefficiency, clinical complications, and improving patient safety. [ABSTRACT FROM AUTHOR]

The capillary dialyzer represents the central element of the extracorporeal blood circuit of a therapy system for hemodialysis. The aim of this study was to assess the blood-flow characteristics of dialyzers with the help of modern ultrasound techniques. Five brand-new dialyzers (FX80 classix, Fresenius Medical Care, Bad Homburg, Germany) and five dialyzers after a dialysis session were analyzed by different ultrasound techniques to detect functional and structural changes. B-mode and Doppler techniques were not suitable to describe differences in brand-new and clinically applied dialyzers. Contrast-enhanced ultrasonography, however, was able to visualize blood-flow profiles in the capillaries. Although dialyzers displayed no signs of clinical dysfunction, contrast-enhanced ultrasonography was able to detect blocked capillaries of varying degrees after a dialysis session in all five examined dialyzers. Consequently, the blood-flow velocity was higher in the remaining unblocked capillaries in comparison to the velocity in the brand-new dialyzers. This information may be helpful for improving the geometric design of dialyzers, including their capillary membranes, and optimizing anti-coagulation strategies in hemodialysis patients. [ABSTRACT FROM AUTHOR]

Convection‐based renal replacement therapies (RRTs) have the potential to improve patient outcomes when compared to diffusion‐based RRT such as hemodialysis (HD), but have limited clearance rates. We propose and characterize multipoint dilution hemofiltration (MPD‐HF), a purely convective blood purification technology which removes the fundamental filtration limit associated with convective RRT resulting in clearance rates on par with HD. In MPD‐HF, filtration of liquid and solutes occurs along the length of the hollow fibers that convey the blood, and substitution fluid is pushed into the fibers at multiple points along their length. Since multiple filtration and dilution steps are contained within one pass of the blood through the hollow fiber, the fraction of fluid that can be filtered may be increased to allow a high clearance rate that removes a wide range of toxins. In vitro tests yielded an average steady‐state filtrate fraction of 68%, exceeding commercial HDF cartridge filtrate fractions by a factor of approximately 3. The molecular weights of molecules cleared spans up to the cutoff of 66 kDa for albumin. [ABSTRACT FROM AUTHOR]

Background: A new class of dialysis membrane, the mid cut-off (MCO) dialyzer, has been developed to improve the clearance of uremic toxins in hemodialysis (HD). The a tRial Evaluating Mid cut-Off Value membrane clearance of Albumin and Light chains in HemoDialysis patients (REMOVAL-HD) study aimed to determine if regular use of MCO dialyzer was safe and specifically did not result in a significant loss of albumin. Methods: This investigator initiated, crossover, longitudinal, device study was conducted across 9 centers in Australia and New Zealand (n = 89). Participants had a 4-week wash-in with high-flux HD, followed by 24-week intervention with MCO HD and a subsequent 4-week wash-out with high-flux HD. The primary outcome was change in serum albumin between weeks 4 and 28. Secondary outcomes included trends in serum albumin, changes in kappa- and lambda-free light chains (FLC), 6-min walk test (6MWT), malnutrition inflammation score (MIS), restless legs score and quality of life. Results: Participants had a mean age of 66 ± 14 years, 62% were men, 45% were anuric, and 51% had -diabetes. There was no reduction in serum albumin following treatment with MCO HD (mean reduction –0.7 g/L, 95% CI –1.5 to 0.1). A sustained, unexplained reduction in serum albumin (>25%) was not observed in any participant. A reduction in FLC was observed 2 weeks into MCO HD (lambda-FLC: Δ –9.1 mg/L, 95% CI –14.4 to –3.7; kappa-FLC: Δ –5.7 mg/L, 95% CI –9.8 to –1.6) and was sustained for the rest of the study intervention. Both FLC increased after the cessation of MCO use. There was no improvement in restless legs symptoms, quality of life, 6MWT or MIS scores. Conclusions: Regular HD using the MCO dialyzer did not result in a significant fall in serum albumin. There were no effects on quality of life, functional status or nutrition. Trial Registration: Australian New Zealand Clinical Trials Registry Number (ANZCTRN) 12616000804482. [ABSTRACT FROM AUTHOR]

Introduction: Online haemodiafiltration (OL-HDF) has been associated with increased survival. To date, the influence of the inner diameter of the hollow fibers of the dialyzer on convective volume has not been well established. The objective of the study was to evaluate the effect of increasing the inner diameter of the dialyzer on the convective volume and removal capacity. Material and methods: We included 16 patients in postdilutional OL-HDF. Each patient was analyzed in 4 sessions in which the inner diameter varied; 185 μm (FX60 Cordiax and FX80 Cordiax) vs. 210 μm (FX600 Cordiax and FX800 Cordiax). Different solutes were measured at the beginning and end of each dialysis session. Results: No differences in the convective volume were found with an increased inner diameter: 32.3 ± 3.1 vs. 31.8 ± 3.6 L/session (FX60 vs. FX600) and 33.7 ± 4.3 vs. 33.5 ± 3.8 L/session (FX80 vs. FX800). The reduction ratios also did not differ: urea 83.7 ± 4.5 vs. 84.1 ± 3.4 for FX60 and FX600, and 82.7 ± 4.1 vs. 83.6 ± 3.8 for FX80 vs. FX800; creatinine similar 78.2 ± 5.6 vs. 77.8 ± 4.6 and 77.1 ± 5.4 vs. 78.1 ± 4.9; β2-microglobulin 82.2 ± 4.3 vs. 82.9 ± 4.2, and 82.9 ± 4.7 vs. 84.0 ± 3.8; myoglobin 71.0 ± 10 vs. 70.2 ± 9 and 72.8 ± 11 vs. 75.0 ± 10; prolactin 70.4 ± 9 vs. 68.1 ± 9, and 72.2 ± 10 vs. 73.4 ± 8.2; and α1-microglobulin 22.9 ± 10 vs. 21.6 ± 10, and 26.5 ± 12 vs. 28.8 ± 11, respectively. Conclusion: The increase in the inner diameter of the hollow fibers did not result in improved convective volume and removal capacity.

The study aim was to compare molecular‐level effects (blood‐dialyzer interactions) of heparin and citrate anticoagulation using proteome‐wide analysis of biofilm adsorbed to dialysis membrane. Ten patients receiving maintenance hemodialysis were examined in a crossover design under three different anticoagulation regimens, namely citrate, heparin, and anticoagulation‐free (control). Following a regular hemodialysis session (4 hours, polysulfone membrane), dialyzers were flushed and the surface biofilm eluted by acetic acid. Protein composition of the eluates was determined by 2‐dimensional gel electrophoresis and resulting patterns compared between regimens. Proteins responsible for the difference were identified by mass spectrometry. Citrate anticoagulation was associated with significantly less protein adsorption to the membrane than heparin (2.2 [1.1‐2.9] mg vs. 6.5 [2.9‐11.6] mg, P = 0.009). Among the proteins identified as major discriminators between citrate and the other regimens, fibrin α‐chain fragments of molecular weight below 40 kDa prevailed. In these fragments, an analysis of the amino acid sequence has been performed by comparison with the UniProt database. It showed missing α‐chain cross‐links. On the contrary, heparin prevented adsorption and cleavage of several heparin‐binding proteins; especially complement factor H‐related protein 3, insulin‐like growth factor binding proteins (2, 4, and 5), and chemerin. Compared to heparin, citrate is associated with less protein adsorption and imperfectly crosslinked fibrin clot formation. Membrane adsorptive properties are significantly modified by the anticoagulation regimen. [ABSTRACT FROM AUTHOR]

Copyright of Nefrologia is the property of Revista Nefrologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Most high‐flux dialyzers can be used in both hemodialysis (HD) and online hemodiafiltration (OL‐HDF). However, some of these dialyzers have higher permeability and should not be prescribed for OL‐HDF to avoid high albumin losses. The aim of this study was to compare the safety and efficacy of a currently used dialyzer in HD and OL‐HDF with those of several other high permeability dialyzers which should only be used in HD. A prospective, single‐center study was carried out in 21 patients. Each patient underwent 5 dialysis sessions with routine dialysis parameters: 2 sessions with Helixone (HD and postdilution OL‐HDF) and 1 session each with steam sterilized polyphenylene, polymethylmethacrylate (PMMA), and medium cut‐off (MCO) dialyzers in HD treatment. The removal ratios (RR) of urea, creatinine, ß2‐microglobulin, myoglobin, prolactin, α1‐microglobulin, α1‐acid glycoprotein, and albumin were compared intraindividually. A proportional part of the dialysate was collected to quantify the loss of various solutes, including albumin. Urea and creatinine RRs with the Helixone‐HDF and MCO dialyzers were higher than with the other 3 dialyzers in HD. The β2‐microglobulin, myoglobin and prolactin RRs with Helixone‐HDF treatment were significantly higher than those obtained with all 4 dialyzers in HD treatment. The β2‐microglobulin value obtained with the MCO dialyzer was also higher than that obtained with the other 3 dialyzers in HD treatment. The myoglobin RR with MCO was higher than those obtained with Helixone and PMMA in HD treatment. The prolactin RR with Helixone‐HD was significantly lower than those obtained in the other 4 study sessions. The α1‐microglobulin and α1‐ acid glycoprotein RRs with Helixone‐HDF were significantly higher than those obtained with Helixone and PMMA in HD treatment. The albumin loss varied from 0.54 g with Helixone‐HD to 3.3 g with polyphenylene. The global removal score values ((UreaRR + β2‐microglobulinRR + myoglobinRR + prolactinRR + α1‐microglobulinRR + α1‐acid glycoproteinRR – albuminRR)/6) were 43.7% with Helixone‐HD, 47.7% with PMMA, 54% with polyphenylene, 54.8% with MCO and 59.6% with Helixone‐HDF, with significant differences. In conclusion, this study confirms the superiority of OL‐HDF over HD with the high‐flux dialyzers that allow both treatments. Although new dialyzers with high permeability can only be used in HD, they are in an intermediate position and some are very close to OL‐HDF. [ABSTRACT FROM AUTHOR]

Background: A novel class of membranes, medium cut-off (MCO) membranes, has recently been designed to achieve interesting removal capacities for middle and large middle molecules in hemodialysis (HD) treatments. The few studies published to date have reported contradictory results regarding middle-sized molecules when comparing MCO dialyzers versus dialyzers used in online hemodiafiltration (OL-HDF). Methods: A prospective, single-center study was carried out in 22 patients. Each patient underwent 9 dialysis sessions with routine dialysis parameters, one with an MCO dialyzer in HD and the other 8 with different dialyzers in OL-HDF. The removal ratio (RR) of urea, creatinine, β2-microglobulin, myoglobin, prolactin, α1-microglobulin, α1-acid glycoprotein, and albumin was intraindividually compared. Albumin loss in dialysate was measured. We propose a global removal score ([ureaRR + β2-microglobulinRR + myoglobinRR + prolactinRR + α1-microglobulinRR + α1-acid glycoproteinRR]/6 – albuminRR) as a new tool for measuring dialyzer effectiveness. Results: No significant differences in the RRs of small and middle molecular range molecules were observed between the MCO vs. OL-HDF dialyzers (range 60–80%). Lower RRs were found for α1-microglobulin and α1-acid glycoprotein without significant differences. The albumin RR was < 11% and dialysate albumin loss was < 3.5 g in all situations without significant differences. The global removal score was 54.9 ± 4.8% with the MCO dialyzer without significant differences. Conclusions: Removal of a wide range of molecular weights, calculated with the proposed global removal score, was almost equal with the MCO dialyzer in HD treatment compared with 8 high-flux dialyzers in high-volume OL-HDF without relevant changes in albumin loss. The global removal score could be a new tool to evaluate the effectiveness of dialyzers and/or different treatment modalities. [ABSTRACT FROM AUTHOR]

Reuse of dialyzers for hemodialysis can help in bringing down the cost of hemodialysis. On the other hand reuse of dialyzer may change dialyzer integrity. This study was undertaken to determine dialyzer reuse effect on Urea Reduction Ratio (URR), Kt/V urea and serum albumin. This was prospective study in Sanglah Public General Hospital Denpasar. Inclusion criteria for this study were patients who receive hemodialysis more than 3 months on twice weekly hemodialysis. In the study we used hollow fiber or dialyzer Elisio type H-130H reprocessed with Renaline automatically by machine renatron. After each session blood urea, post dialysis weight and serum albumin were measured. Measurements was performed on the use new dialyzer, 1st reuse, 4th reuse and 7th reuse. The dialyzer was discarded, if TCV fell below 80% of baseline value. Kt/V and urea reduction ratio (URR) were calculated as measure of dialysis adequacy. A total of 23 people completed the study. There was a lack of uniformity duration of hemodialysis, so that we also performed an analysis using a uniform length hemodialysis duration (4.5 hours) with 15 samples. There were no significant difference between URR and Kt/V urea of new dialyzer and dialyzer reprocessed by renaline respectfully with p=0.131 and p=0.373. If we analyzed only using uniform time of dialysis (4.5 h) the value of URR and Kt/V urea between new and reused dialyzer not significantly different with p=0.520 and p=0.784. There was also not found significant differences between serum albumin of the use new dialyzer and reused dialyzer by the time of uniform or non-uniform, respectfully with p=0.271 and 0.073. Reuse dialyzer does not alter efficacy of hemodialysis.

Sieving coefficients reported in dialyzer data sheets and instructions for use (IFUs) indicate the potential of different solutes to pass across a particular membrane. Despite being measured in vitro, sieving coefficient data are often used as a predictor of the clinical performance of dialyzers. Although standards for the measurement of sieving coefficients exist, the stated methodologies do not offer sufficient guidance to ensure comparability of test results between different dialyzers. The aim of this work was to investigate the relationship between sieving coefficients and published clinical performance indicators for two solutes, albumin loss and beta‐2 microglobulin (β2M) reduction ratio (RR), and to assess the impact of different in vitro test parameters on sieving coefficient values for albumin, β2M, and myoglobin. Clinical albumin loss and β2M RR for commercially available dialyzers used in hemodialysis (HD) and post‐dilution hemodiafiltration (HDF) were extracted from the literature and plotted against sieving coefficients reported in data sheets and IFUs. Albumin, β2M, and myoglobin sieving coefficients of a selection of dialyzers were measured per the ISO 8637 standard. The impact of in vitro testing conditions was assessed by changing blood flow rate, ultrafiltration (UF) rate, sampling time, and origin of test plasma. Results showed variation in albumin loss and β2M RR for the same sieving coefficient across different dialyzers in HD and HDF. Changes in blood flow rates, UF rates, sampling time, and test plasma (bovine vs. human) caused marked differences in sieving coefficient values for all investigated solutes. When identical testing conditions were used, sieving coefficient values for the same dialyzer were reproducible. Testing conditions have a marked impact on the measurement of sieving coefficients, and values should not be compared unless identical conditions are used. Further, variability in observed clinical data in part reflects the lack of definition of test conditions. [ABSTRACT FROM AUTHOR]

Background/Aims: A recent alert from Spanish health authorities warned of a higher incidence of reported hypersensitivity reactions to hemodialysis membranes with polysulfone, in the 2017 review of acute reactions to dialyzers found only published reports in the 21st century on polysulfone and its derivatives. The aim is to assess/evaluate the current incidence and characteristics of hypersensitivity reactions in hemodialysis patients. Methods: A retrospective multicentre study in 9 Spanish hospitals evaluated patients in whom a hypersensitivity reaction required a change in dialyzer membrane. Results: A total of 37 patients out of 1561 (2.37%) had hypersensitivity reactions and clinical, epidemiological and analytical data were available for 33 patients (2.11%). The membranes involved were polysulfone (n=23), polynephron (n=8), polyethersulfone (n=1) and polyacrylonitrile (n=1). This distribution reflected the frequency of use of membranes in the participating dialysis units. The reactions were described as type A in 18 cases and type B in 15 cases. There were no significant differences between the two types in clinical symptoms, the composition of the membrane involved, the method of sterilization, the season, or the time during the session in which they occurred. The most frequent symptom was dyspnea/breathlessness (64% of reactions). Eosinophilia was common (74%). 54% of the reactions occurred within the first 30 minutes of hemodialysis, 64% occurred during the first year of dialysis, and 54% required discontinuation of dialysis session. Cellulose triacetate was used as an alternative dialyzer in 78% of the cases. Conclusion: The incidence of hypersensitivity reactions was in the range found in reports from 20 years ago and is observed associated with synthetic membranes, not just polysulfones. Cellulose triacetate appears to be a good alternative for these patients. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to use proteomics methods to investigate the changes in serum protein levels after high- and low-flux hemodialysis (HD). Methods: Before and after HD, serum samples were obtained from two selected patients who were treated with a Polyflux 140 H high-flux dialyzer and a Polyflux 14 L low-flux dialyzer during two continuous therapy sessions. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was performed to identify the proteins. Results: A total of 212 and 203 serum proteins were identified after high-flux and low-flux HD, respectively. After high-flux HD, 21 proteins increased, and 132 proteins decreased. After low-flux HD, 87 proteins increased, and 45 proteins decreased. High-flux HD led to a significantly greater reduction in protein levels than low-flux HD (0.73 ± 0.13 vs. 0.84 ± 0.18, p = .00). Among the increased and decreased proteins, the isoelectric point (pI) values mainly ranged from 5 to 7, and the molecular weights (Mws) were mostly smaller than 30 kDa. The serum proteins showed no difference in pI or Mw for high- and low-flux HD. Gene ontology (GO) analysis showed that the detected proteins were related to immune system processes and complement activation. Conclusions: Serum protein levels differentially changed after high- and low-flux HD. Long-term effects should be observed in future studies. [ABSTRACT FROM AUTHOR]

It is challenging to improve the hemocompatibility of commercial dialyzers packaging more than 10,000 fibers. Herein, we report the preparation and evaluation of a self-anticlotting Polysulfone dialyzer via an interface crosslinking approach. By modulating the conformation of sulfate, carboxyl groups and pyrrolidone (VP) in heparin-like polymers, the hemocompatibility of the dialyzer was significantly improved. It was found that the sequential structure of functional groups influenced the anticoagulant performances substantially. The hollow fiber modified by the blended polymer (Poly (N-vinyl-2-pyrrolidone- co -triethoxyvinylsilane) and poly (Sodium 4-vinylbenzenssulfonate- co -triethoxyvinylsilane- co -Acrylic acid) (P(VP-VTES)- b -P(SSNa-VTES-AA))) exhibited better hemocompatibility than the contrast membrane modified by poly (Acrylic acid- co -triethoxyvinylsilane- co -N-vinyl-2-pyrrolidone- co - - co -Sodium 4-vinylbenzenssulfonate) (P(AA-VTES-VP-SSNa)). The chemical composition was determined by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectra (FTIR). The morphology of the hollow fiber membranes was observed by a scanning electron microscopy (SEM). The thrombin time (TT), plasma fibrinogen (FIB), activated partial thromboplastin time (APTT), prothrombin time (PT) and protein adsorption were measured to examine the hemocompatibility. The modified hollow fiber showed self-anticlotting properties with excellent protein resistance, remarkably prolonged coagulation time (APTT > 600 s), suppressed complement activation and nontoxicity to osteoblasts. The modified dialyzer showed practicable ultrafiltration coefficient and clearance performance, indicating its great potential application in dialysis treatment. [ABSTRACT FROM AUTHOR]

The objectives of hemodialysis have moved from the diffusive clearance of small molecular weight uremic toxins and achieving dialyzer urea adequacy targets to emphasis on improving clinical outcomes in end stage renal failure patients by increasing larger sized uremic toxin clearance. Clinical emphasis in the last few decades has focused on increasing middle molecule weight toxin clearance by hemodiafiltration. Although long‐term data is still lacking, short‐term outcomes appear promising. Advancements in nanotechnology have now introduction a new generation of medium cut‐off membrane dialyzers which allow diffusive clearance of similar middle molecular weight uremia toxin clearance as hemodiafiltration, without increased albumin losses. As these dialyzers have only recently been introduced into clinical practice, no long‐term outcomes are available to determine the relative benefits or advantages of this approach. As dialyzers are now designed to maximize diffusive or convective clearance, or provide a combination, then clinicians can now choose dialyzers tailored to the individual patient needs depending on clinical circumstances. We review the key important features in choosing a dialyzer for patients with end stage renal failure and acute kidney injury. [ABSTRACT FROM AUTHOR]

Introduction: Polysulfone (PSf) membrane has been widely used for hemodialysis. A few studies have been reported in which a method of sterilization may affect biocompatibility. In this study, the comparison was made between two PSf membranes in order to evaluate the effect of sterilization from the biocompatibility point of view. Methods: We investigated the biocompatibility of the following two dialyzers, that is, APS‐11SA (Asahi Kasei medical Co., Tokyo, Japan), sterilized by gamma‐ray irradiation, and RENAK PS‐1.0 (Kawasumi laboratories, Tokyo, Japan), sterilized by autoclave. Heparin of 40 units/mL was put in a syringe, and test blood was collected from healthy volunteers. Then, the dialyzer and blood circuit were filled with the test blood. Subsequently, the blood was circulated by a roller pump at the rate of 200 mL/min. We measured the platelet counts, CD41 and CD42b platelet surface markers, beta‐thromboglobulin (beta‐TG) and platelet factor 4 (PF4) at 30, 120, and 240 minutes, respectively. Findings: The platelet counts at 30, 120, and 240 minutes decreased significantly from the initiation of blood circulation in both dialyzers. The average beta‐TG and PF4 increased from 61.3 ± 22.1 and 17.0 ± 6.4 ng/mL to 680.7 ± 217.1 and 550.7 ± 116.7 ng/mL with APS‐11SA and to 454.3 ± 85.6 and 402.0 ± 58.0 ng/mL with RENAK PS‐1.0, respectively. The average expression of CD41 and CD42b in APS‐11SA and RENAK PS‐1.0 was similar. Discussion: There are some reports that the gamma‐ray irradiation changes the membrane structure of the PSf membrane, crosslinking the polyvinylpyrrolidone (PVP), a hydrophilic agent, on to the membrane. On the other hand, excess amount of PVP may have been eluted during the rinsing procedure in RENAK PS‐1.0 because it was sterilized with autoclave. Because both these factors influenced on our results, APS‐11SA and RENAK PS‐1.0 dialyzers showed excellent blood compatibility. [ABSTRACT FROM AUTHOR]