Polyvinylpyrrolidone in hemodialysis membranes: Impact on platelet loss during hemodialysis

Abstract

Introduction: Hydrophilic modification with polyvinylpyrrolidone (PVP) increases the biocompatibility profile of synthetic dialysis membranes. However, PVP may be eluted into the patient's blood, which has been discussed as a possible cause for adverse reactions rarely occurring with synthetic membranes. We investigated the content of PVP and its elution from the blood-side surface from commercially available dialyzers, including the novel FX CorAL, with PVP-enriched and α-tocopherol-stabilized membrane, and link the results to the level of platelet loss during dialysis as a maker of biocompatibility. Methods: Six synthetic, PVP containing, dialyzers (FX CorAL, FX CorDiax [Fresenius Medical Care]; Polyflux, THERANOVA [Baxter]; ELISIO [Nipro]; xevonta [B. Braun]) were investigated in the present study. The content of PVP on blood-side surface was determined with X-ray photoelectron spectroscopy (XPS). The amount of elutable PVP was measured photometrically after 5 h recirculation. The level of platelet loss was evaluated in an ex vivo recirculation model with human blood. Findings: Highest PVP content on the blood-side surface was found for the polysulfone-based FX CorAL (26.3%), while the polyethersulfone-based THERANOVA (15.6%) had the lowest PVP content. Elution of PVP was highest for the autoclave steam-sterilized THERANOVA (9.1 mg/1.6 m 2 dialyzer) and Polyflux (9.0 mg/1.6 m 2 dialyzer), while the lowest PVP elution was found for the INLINE steam sterilized FX CorAL and FX CorDiax (<0.5 mg/1.6 m 2 dialyzer, for both). Highest platelet loss was found for xevonta (+164.4% compared to the reference) and the lowest for the FX CorAL (À225.2%) among the polysulfone-based dialyzers; among the polyethersulfone-based dialyzers, THERANOVA (+95.5%) had the highest and ELISIO (À52.1%) the lowest platelet loss. Discussion: Polyvinylpyrrolidone content and elution differ between commercially available dialyzers and were found to be linked to the membrane material and sterilization method. The amount of non-eluted PVP on the blood-side surface may be an important determinant for the biocompatibility of dialyzers.

Randomized comparison of three high-flux dialyzers during high-volume online hemodiafiltration—the comPERFORM study

“…The reduced albumin adsorption seen over the first hour with FX CorAL 600 is thought to originate from the dialyzer membrane's almost neutral surface charge and its higher PVP concentration on the inner surface, which stabilizes a membrane-protective hydro layer [ 12 ]. It is important regarding tolerability that this high PVP concentration on the FX CorAL's membrane does not lead to high elution [ 27 ]. Recent in vitro experiments indicated that PVP elution is different between dialyzers and depends on membrane material and method of sterilization [ 27 ].…”

“…It is important regarding tolerability that this high PVP concentration on the FX CorAL's membrane does not lead to high elution [ 27 ]. Recent in vitro experiments indicated that PVP elution is different between dialyzers and depends on membrane material and method of sterilization [ 27 ].…”

Immune System Dysfunction and Inflammation in Hemodialysis Patients: Two Sides of the Same Coin

“…The fall in platelet count observed with polysulfone membranes has been attributed to platelet activation, rather than complement activation, as revealed in the recent decades, during cuprophane membrane use [36]. Conversely, synthetic membranes based on polysulfone or polyethersulfone, but blended with polyvinylpyrrolidone as a hydrophilic agent, had an excellent biocompatibility profile, reducing protein fouling and platelet adsorption [37,38]. Furthermore, the use of heparin does not block the coagulation and platelet activation steps, unlike the more effective anticoagulant citrate.…”

“…Pro-thrombotic status mediated by activated intrinsic and extrinsic pathways leading to pro-inflammatory effects and endothelial cell damage Platelet dysfunction with atypical activation D-dimer, β-TG TAT Anticoagulant citrate [39,40] Polyvinylpyrrolidone [37,38] Oxidative Stress…”

Time‐resolving characterization of molecular weight retention changes among three synthetic high‐flux dialyzers

“…Recent in vitro studies found substantial differences in the PVP content and elution as well as in the secondary membrane formation of different dialyzer membranes 17,21 . These studies investigated the novel FX CorAL dialyzer, which was developed to achieve positive effects on hemocompatibility via increased and stabilized PVP on the blood‐side surface of the membrane.…”