Comparison of Molecule Clearance and Pro-Inflammatory Markers Between High-Flux and Medium Cut-Off Dialyzers (ELISIO™ 21): A Crossover Pilot Study

Background: Chronic kidney disease (CKD) is increasingly prevalent, leading to more patients requiring hemodialysis. Medium cut-off (MCO) membranes, such as the ELISIO™ HX dialyzer, may enhance middle-to-large molecule removal and reduce inflammation compared with conventional high-flux membranes. This study evaluated the efficacy and safety of ELISIO™ HX versus a standard high-flux dialyzer (Toraylight NS-21S) in terms of molecular reduction rate and inflammation. Methods: We performed a single-center, prospective, randomized crossover study with 12 hemodialysis patients, each treated with Toraylight NS-21S and ELISIO™ HX over four weeks. Pre- and post-dialysis levels of urea, creatinine, albumin, creatine kinase, phosphorus, parathyroid hormone, C-reactive protein (CRP), procalcitonin, interleukin 6 (IL-6), and β2-microglobulin were measured. Pre–post differences were assessed using dialyzer analysis, period-effect and carryover analysis, and non-inferiority analysis. Results: ELISIO™ HX was non-inferior to Toraylight NS-21S for creatinine, urea, phosphorus, procalcitonin, and β2-microglobulin. No significant serum albumin changes were observed with either dialyzer. Adverse events were infrequent and comparable between the dialyzers. Conclusions: ELISIO™ HX appears non-inferior to Toraylight NS-21S and suggests good safety and tolerability. These findings should be interpreted with caution given the study’s limited power.