Beta-2 microglobulin removal with postdilution online hemodiafiltration – comparison of three different dialysis membranes

Introduction Accumulation of middle molecular weight uremic toxins causes various complications in chronic hemodialysis (HD) patients. Postdilution online hemodiafiltration (OL-HDF) efficiently removes these molecules. This study aimed to assess the effectiveness of three different dialysis membranes in removing β2-microglobulin (β2 m) within a single session of postdilution OL-HDF. Method A prospective single-center study was carried out in 30 patients (23 males and seven females, average age 54.87 ± 11.66 years, time on dialysis 4.95 ± 5.4 years) on maintenance HD. Each patient was followed for three consecutive weeks on OL-HDF with three different dialyzers: DiacapPro 19H, FX CorDiax 800, and Elisio 21H, randomly switched weekly. The reduction ratios (RR) of β2 m and albumin were compared individually. The results were analyzed with the Kolmogorov–Smirnov test, ANOVA, and the Kruskal–Wallis test. Results The average convective volume for all patients was 21.38 ± 2.97 L/session. β2-m RR was 70.86 ± 6.87%, 74.69 ± 6.51%, and 70.04 ± 9.37% with Diacap Pro 19H, FX CorDiax 800 and Elisio 21H membrane, respectively (p = 0.054). Albumin RR was 6.20 ± 2.12% with Diacap Pro 19H membrane, 6.01 ± 2.97% with FX CorDiax 800 membrane, and 6.46 ± 2.91% with Elisio 21H membrane (p = 0.812). Albumin loss was < 4 g/dialysis treatment for all membranes. Conclusion All investigated membranes effectively remove β2-m in postdilution OL-HDF with a tolerable albumin loss. The highest β2-m RR was determined for FX CorDiax 800 membrane, but with no statistically significant difference