Brunati CCM, et al. - Researchers investigated the influence of NxStage System One cycler (NSO), a “low dialysate volumes system”, on the removal rate of poorly diffusible, time-dependent solutes like β₂-microglobulin (β₂M). For this purpose, they performed single-session and weekly balances of β₂M. These were compared in patients on daily NSO (n=12), on standard high-flux bicarbonate dialysis (BHD, n=13), on standard post-dilution on line hemodiafiltration (HDF, n=5), and 13 patients on automated peritoneal dialysis (APD). HDF and NSO (at a 6/week prescription) had equal weekly β₂M removal efficiency and provided the highest weekly β₂M removal, which was slightly lesser in BHD and lowest in APD.