β2-microglobulin removal and plasma albumin levels with high cut-off hemodialysis

Purpose. β2-microglobulin (β2MG) is pivotal to the pathogenesis of dialysis-related amyloidosis. We compared the effects of high cut-off hemodialysis (HCO-HD) with those of standard high-flux hemodialysis (HF-HD) regarding the concentration and clearance of β2MG and albumin. Design. We enrolled ten patients with acute renal failure in a double-blind, cross-over, randomized controlled trial. Procedures Each patient received four hours of HCO-HD (estimated in vivo cutoff 50–60 kDa) and four hours of HF-HD (estimated in vivo cutoff 15–20 kDa) in random order. Statistical methods and outcome measures: As data lacked normal distribution, we used non-parametric statistical analysis. Plasma and dialysate concentrations of β2MG and albumin were measured at baseline and after four hours of each study treatment. Main findings. We found significantly greater diffusive β2MG clearances for HCO-HD compared to HF-HD (at the start: 71.8 ml/min vs. 5.1 ml/min; P=0.008 and at the end: 68.8 ml/min vs. 5.7 ml/min; P=0.008). We found a reduction in plasma β2MG concentrations of -31.6% during HCO-HD compared to an increase by 25.7% during HF-HD; P=0.008. At baseline (HCO-HD: 26.0 g/L vs. HF-HD: 26.5 g/L), and at the end of both treatments, plasma albumin concentrations were comparable (HCO-HD: 25.5 g/L vs. HF-HD: 26.5 g/L; P=0.25). During HCO-HD, albumin clearance was 1.9 ml/min at the start and decreased significantly to 0.8 ml/min at the end; P=0.008. HF-HD had an albumin clearance of 0.01 ml/min. Conclusions. HCO-HD was more effective in decreasing plasma β2MG concentrations than standard HF-HD and did not reduce plasma albumin levels. Further studies of HCO-HD in the treatment of dialysis-related β2MG accumulation appear warranted. ( ClinicalTrials.gov number, NCT00333593 [ ClinicalTrials.gov ]) (Int J Artif Organs 2007; 30: 385–92)