Comparison of Protein-bound Toxins Removals Between Limited Blood Flow Online Hemodiafiltration Using Super High-flux Dialyzer and High-Efficiency Online Hemodiafiltration With High-flux Dialyzer: An Randomized Crossover Trial

Elevated protein-bound toxins including p-cresol (pCS) and indoxyl sulfate (IDS) as well as middle-molecular toxins such as beta2-microglobulin (B2M) which could not be removed by hemodialysis (HD) are obviously correlated with high mortality. High-efficiency post-dilution online hemodiafiltration (OL-HDF) using high-flux dialyzer and requiring high blood flow rate (BF ≥400 mL/min) has been reported to enhance pCS, IDS, and B2M removal and improve patient survival. Unfortunately, the majority of patients could not reach that high BF because of vascular access issue. We innovated the OL-HDF modality for this limited BF situation by integrating the novel super high-flux membrane dialyzer (SHF; PES-17Dα, Nipro Corporation, Japan) into pre-dilution OL-HDF. This randomized crossover study was conducted to compare the uremic toxin removals between the new modality (limited BF OL-HDF with SHF) and the control (high-efficiency OL-HDF). The OL-HDF patients were randomized to undergo either new modality or control for 2 weeks before crossover to the other modality for another 2 weeks. Removals of pCS and IDS as well as small and middle molecule toxins were compared. The pCS and IDS were measured by high performance liquid chromatography. The dialysate albumin loss and patient safety were also monitored.