MO642: Comparison of Medium Cut-Off Dialyzer and Post-Dilution Hemodiafiltration on the Removal of Small and Middle Molecule Uremic Toxins

Abstract

Abstract BACKGROUND AND AIMS The medium cut-off (MCO) dialyzer increases the removal of several middle molecules more effectively than high-flux hemodialysis (HD). However, there are no comparable data on the efficacy and safety of MCO dialyzers versus post-dilution hemodiafiltration (HDF) in Korean patients. METHOD A total of 9 patients with chronic HD were included in this crossover study. Patients received HD with an MCO dialyzer for 4 weeks, followed by a 2-week washout period, using a high-flux dialyzer to minimize carry-over effects and then crossed over to post-dilution HDF for 4 weeks. Reduction ratios and differences in the values before and after were calculated from the MCO dialysis, post-dilution HDF and high-flux HD. In the in vitro study, EA.hy926 cells were treated with dialyzed serum. RESULTS Compared with post-dilution HDF, the MCO dialyzer achieved significantly higher reduction ratios for larger middle molecules [myoglobin, kappa free light chain (κFLC) and lambda FLC (λFLC)]. Similarly, the differences between before and after the last dialysis session of myoglobin, κFLC, and λFLC were significantly greater in MCO dialysis than in post-dilution HDF. The expression of Bax and nuclear factor-κb was decreased in the serum after dialysis with the MCO dialyzer than with HDF. CONCLUSION Compared with high-volume post-dilution HDF, MCO dialysis showed no differences in the removal of molecules below 12 000 Da, whereas it was superior in the removal of larger uremic middle molecule toxins in patients with kidney failure. Moreover, these results might be expected to have an anti-apoptotic effect on the human endothelium.