Super high-flux hemodialysis provides comparable effectiveness with high-volume postdilution online hemodiafiltration in removing protein-bound and middle-molecule uremic toxins: A prospective cross-over randomized controlled trial.

Although high-volume postdilution online hemodiafiltration (ol-HDF) is superior to high-flux HD in removing all kinds of uremic toxins and improving survival, this treatment is not available in most HD centers. The present study was conducted to compare the effectiveness in removals of protein-bound (indoxyl sulfate [IS]), middle-molecule [beta-2 microglobulin (B2M) and alpha-1 microglobulin (A1MG)], and small-molecule uremic toxins between super high-flux HD (SHF-HD), HD with a novel SHF dialyzer and high-volume postdilution ol-HDF in a noninferiority fashion. Fifteen prevalent HD patients were randomly allocated into two sequences of 12-week treatment periods of SHF-HD treatment and later high-volume postdilution ol-HDF period or vice versa. Each treatment period was divided by a wash-out phase of 4-week high-flux HD. Twelve of 15 patients could complete the study. When compared with high-volume postdilution ol-HDF (convective volume of 24.4 ± 3.52 L), SHF-HD provided comparable reduction ratio values of IS, B2M, and A1MG with mean difference of 5.87 (95% confidence interval [CI] -1.63, 13.37), 1.98 (95% CI,-0.21, 4.18), and 22.96 (95% CI, -1.91, 47.83), respectively. The spKt/Vurea was not different. The predialysis levels of all uremic toxins at baseline and after 12-week treatment did not differ between both groups. Although albumin loss in dialysate in SHF-HD was greater than high-volume postdilution ol-HDF, the serum albumin levels after 12-week SHF-HD treatment were significantly higher than baseline. In conclusion, SHF-HD provides noninferior effectiveness to high-volume postdilution ol-HDF in removing various uremic toxins with significantly increased serum albumin levels despite higher albumin loss. SHF-HD might be an effectively alternative treatment when high-volume postdilution ol-HDF is not available.