β 2 -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)