A randomized trial comparing medium cut-off membrane dialyzers with online hemodiafiltration for uremic toxins clearance in hemodialysis patients
Eakalak Lukkanalikitkul, Hansa Kidkaem, Maneerat Phonrat, Pantaree Prathompong, Sirirat Anutrakulchai
Abstract
Online hemodiafiltration (Ol-HDF) and expanded hemodialysis (HDx; using medium cut-off dialyzers) have shown superior removal of diverse uremic toxins, particularly middle molecules and inflammatory cytokines, compared to conventional hemodialysis (HD). However, the relative efficacy of toxin removal between HDx and Ol-HDF remains unclear. This study aimed to compare these two techniques. A randomized controlled trial was conducted among thrice-weekly hemodialysis patients. Participants were randomized into either a post-dilution Ol-HDF group or an HDx group using two types of medium cut-off dialyzers (Theranova 500 ® and Elisio HX21 ® ) over 8 weeks. Efficacy was assessed by reduction ratios (RR) and pre-dialysis toxin levels. Statistical analysis used T-tests and generalized estimating equations. A total of 40 patients were enrolled (mean age 64.6 ± 12.0 years; 82.5% male; dialysis vintage 53.4 ± 38.0 months). The Ol-HDF group, with a mean convection volume of 24.7 L, had significantly higher RR for beta-2 microglobulin (82.8% vs. 74.6%; p < 0.001), parathyroid hormone (80.4% vs. 60.6%; p = 0.007), homocysteine (58.0% vs. 50.0%; p = 0.009), and kappa- and lambda-free light chains (73.3% vs. 64.6%; p = 0.0001 and 62.5% vs. 52.0%; p = 0.0026, respectively). Pre-dialysis toxin levels at the end of the study were similar between groups. These findings highlight that Ol-HDF demonstrated superior removal of uremic toxins, while HDx was comparable to Ol-HDF in maintaining pre-dialysis levels of middle molecules and inflammatory cytokines. Trial registration This study was registered in the Thai Clinical Trials Registry (TCTR) on the first posted date 10/02/2023 with the registration number TCTR20230210004.