Efficacy in the reduction ratios of middle molecules with the use of medium cutoff dialyzers and reduced dialysate flows: A cohort study

Juan Carlos Mario Castillo¹Cesar Doria²Javier Cely³David Camargo⁴Viviana Orozco⁵Daniel Ducuara⁶Jasmin Vesga Gualdron⁷Mauricio Sanabria^8*Angela Rivera⁹Bengt Lindholm¹⁰Peter Rutherford¹¹

• ¹Renal Care Services Agencia Soacha, Soacha, Colombia
• ²Renal Care Services Sucursal Bucaramanga, Bucaramanga, Colombia
• ³Renal Care Services Agencia Nacional, Bogota, Colombia
• ⁴Renal Care Services Agencia Instituto Nacional del Riñon, Bogota, Colombia
• ⁵Renal Care Services Agencia Cardioinfantil, Bogota, Colombia
• ⁶Renal Care Services Agencia San Rafael, Bogota, Colombia
• ⁷Renal Care Services-Colombia, Bucaramanga, Colombia
• ⁸Renal Care Services Latin America, Bogota, Colombia
• ⁹Vantive, Deerfield, United States
• ¹⁰Renal Medicine and Baxter Novum, Karolinska Institutet, Stockholm, Sweden
• ¹¹Vantive, Zurich, Switzerland

Introduction Expanded hemodialysis (HDx) enabled by Theranova increases the clearance of medium-sized molecules, improving clinical outcomes such as hospitalization and mortality. The objective of the study was to compare solute reduction ratios of medium-molecular-weight uremic toxins by HDx versus high-flux hemodialysis (HF-HD) with dialysate flow rates of 400 mL/min and 500 mL/min. Methods In 287 prevalent adult dialysis patients (mean age 61 years, 67% were men, 42.5% had diabetic kidney disease, and 16.7% had urine output ≥250 mL/day), the solute reduction ratio of circulating middle molecules was determined at 4 weeks and 12 weeks of follow-up in two cohorts, one with HDx (n=137) and one with HF-HD (n=150). A mixed-effects repeated measures model was used to evaluate differences between treatment groups. The frequencies of serious adverse events and hospitalization were also calculated. Results The HDx group achieved greater efficiency compared with HF-HD group in removing β2-microglobulin and free light chains (lambda and kappa); this superiority was statistically significant for both dialysate flow rates of 400 mL/min and 500 mL/min. We observed 25.9% fewer serious adverse events in the HDx cohort, none of which were causally related to the Theranova dialyzer or HF-HD treatment during 11,409 sessions. Conclusions 3 HDx enabled by Theranova dialyzer significantly improved the removal of medium-molecular-weight uremic toxins compared to HF-HD at dialysate flow rates of 500 mL/min and 400 ml/min, with fewer serious adverse events and hospitalization events. These findings support the use of the environmentally sustainable dialysis treatment of HDx with dialysate flow rate of 400 ml/min.