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Abstract: SA-PO563

Endotoxin Retentive Performance of the Fresenius FX CorAL Dialyzer

Session Information

Category: Dialysis

  • 801 Dialysis: Hemodialysis and Frequent Dialysis


  • Henrie, Michael E., Value Stream Dialyzers, Fresenius Medical Care, Ogden, Utah, United States
  • Ho, Chih-Hu, Value Stream Dialyzers, Fresenius Medical Care, Ogden, Utah, United States

Many dialyzer innovations focus on improving solute removal or sequestration of target molecules. However, these improvements may impact peripheral dialyzer functions, such as prevention of pyrogenic substances from entering patient blood. This study explored the transmembrane flux and retention of endotoxins for the following dialyzers: FX CorAL 80 and Optiflux F180NRe (Fresenius Medical Care), and Theranova 400 (Baxter International). FX CorAL (F), a new dialyzer featuring novel Helixone hydro membrane, Optiflux (O), a membrane known for endotoxin performance, and Theranova (T), a medium cut-off (MCO) membrane.


In-vitro experiments used culture filtrates of P. aeruginosa (ATCC 27853) and S. maltophilia (ATCC 13637) spiked into saline to create a solution containing > 200 EU/mL. Dialyzers were challenged under diffusive and convective test configurations, with samples taken during both configurations at 5, 15, 30, and 60 minutes. Samples were analyzed for endotoxin using a kinetic turbidimetric LAL assay with a detection limit of 0.001 EU/mL.


Diffusive transmembrane flux of endotoxin was observed for all dialyzers, with F and O nearly 103 lower than T. Maximum diffusive endotoxin concentrations: F = 0.0016 EU/mL; O = 0.0209 EU/mL; T = 30.98 EU/mL. Convective endotoxin flux decreased over time for all dialyzers, with T plateauing higher than O or F. Log reduction values were calculated from convective samples at 60 minutes: T = 1.61; F = 4.26; O = 4.72.


Endotoxin retention of dialysis membrane is a final barrier in the transfer of pathogens to patients. This is an important membrane quality, since endotoxins present in dialysate will contribute to chronic inflammation in patients. FX CorAL demonstrates endotoxin retentive performance similar to Optiflux, and better than Theranova. Improved understanding of endotoxin removal mechanisms may lead to enhanced endotoxin retention in parallel with dialysis membrane development.


  • Commercial Support – Fresenius Medical Care