Complement activation by dialysis membranes and its association with secondary membrane formation and surface charge. Issue 7 (13th February 2021)

• Record Type: Journal Article
• Authors: Melchior, Pascal; Erlenkötter, Ansgar; Zawada, Adam M.; Delinski, Dirk; Schall, Christian; Stauss‐Grabo, Manuela; Kennedy, James P.
• Is Part Of: Artificial organs. Volume 45:Issue 7(2021)
• Page Start: 770
• Page End: 778
• Publication Date: 2021-02-13
• Subjects: biocompatibility -- complement activation -- hemocompatibility -- hemodialysis membranes -- membrane potential -- protein fouling; Artificial organs -- Periodicals; 617.956
• DOI: 10.1111/aor.13887
• Languages: English
• ISSNs: 0160-564X

Abstract

Abstract: Activation of the complement system may occur during blood‐membrane interactions in hemodialysis and contribute to chronic inflammation of patients with end‐stage renal disease. Hydrophilic modification with polyvinylpyrrolidone (PVP) has been suggested to increase the biocompatibility profile of dialysis membranes. In the present study we compared the complement activation of synthetic and cellulose‐based membranes, including the polysulfone membrane with α‐tocopherol‐stabilized PVP‐enriched inner surface of the novel FX CorAL dialyzer, and linked the results to their physical characteristics. Eight synthetic and cellulose‐based dialyzers (FX CorAL, FX CorDiax [Fresenius Medical Care]; Polyflux, THERANOVA [Baxter]; ELISIO, SUREFLUX [Nipro]; xevonta [B. Braun]; FDX [Nikkisio Medical]) were investigated in the present study. Complement activation (C3a, C5a, and sC5b‐9) was evaluated in a 3 hours ex vivo recirculation model with human blood. Albumin sieving coefficients were determined over a 4 hours ex vivo recirculation model with human plasma as a surrogate of secondary membrane formation. Zeta potential was measured as an indicator for the surface charge of the membranes. The FX CorAL dialyzer induced the lowest activation of the three complement factors (C3a: −39.4%; C5a: −57.5%; and sC5b‐9: −58.9% compared to the reference). Highest complement activation was found for the cellulose‐based SUREFLUX (C3a: +154.0%) and the FDX (C5a: +335.0% and sC5b‐9: +287.9%) dialyzers. Moreover, the FX CorAL dialyzer had the nearest‐to‐neutral zeta potential (−2.38 mV) and the lowest albumin sieving coefficient decrease over time. Albumin sieving coefficient decrease was associated with complement activation by the investigated dialyzers. Our present results indicate that the surface modification implemented in the FX CorAL dialyzer reduces the secondary membrane formation and improves the biocompatibility profile. Further clinical studies are needed to investigate whether these observations will result in a lower inflammatory burden of hemodialysis patients. Abstract : Hydrophilic modification with polyvinylpyrrolidone (PVP) has been previously shown to increase the biocompatibility profile of synthetic dialysis membranes. We now compared the complement activation of different synthetic and cellulose‐based membranes, including the polysulfone membrane with α‐tocopherol‐stabilized, PVP‐enriched inner surface of the novel FX CorAL dialyzer, and linked the results to their physical characteristics. Our results indicate that the surface modification implemented in the FX CorAL dialyzer reduces secondary membrane formation and improves the biocompatibility profile.