Resistance to intercompartmental mass transfer limits beta2-microglobulin removal by post-dilution hemodiafiltration

Kidney Int. 2006 Apr;69(8):1431-7. doi: 10.1038/


Although clearance of beta(2)-microglobulin is greater with hemodiafiltration than with high-flux hemodialysis, beta(2)-microglobulin concentrations after long-term hemodiafiltration are only slightly less than those obtained with high-flux hemodialysis. Resistance to beta(2)-microglobulin transfer between body compartments could explain this observation. beta(2)-Microglobulin kinetics were determined in patients receiving on-line post-dilution hemodiafiltration for 4 h with 18 l of filtration. Plasma beta(2)-microglobulin concentrations were measured during and for 2 h following hemodiafiltration and immediately before the next treatment. The filter clearance of beta(2)-microglobulin was determined from arterial and venous concentrations. The beta(2)-microglobulin generation rate was calculated from the change in the plasma concentration between treatments. The intercompartmental clearance was obtained by fitting the observed concentrations to a two-compartment, variable volume model. The plasma clearance of beta(2)-microglobulin by the filter was 73 +/- 2 ml/min. Plasma beta(2)-microglobulin concentrations decreased by 68 +/- 2% from pre- to post-treatment (27.1 +/- 2.2-8.5 +/- 0.7 mg/l), but rebounded by 32+/-3% over the next 90 min. The generation rate of beta(2)-microglobulin was 0.136 +/- 0.008 mg/min. The model fit yielded an intercompartmental clearance of 82 +/- 7 ml/min and a volume of distribution of 10.2 +/- 0.6 l, corresponding to 14.3 +/- 0.7% of body weight. Hemodiafiltration provides a beta(2)-microglobulin clearance of similar magnitude to the intercompartmental clearance within the body. As a result, intercompartmental mass transfer limits beta(2)-microglobulin removal by hemodiafiltration. This finding suggests that alternative strategies, such as increased treatment times or frequency of treatment, are needed to further reduce plasma beta(2)-microglobulin concentrations.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Body Fluid Compartments*
  • Body Weight
  • Female
  • Hemodiafiltration*
  • Hemodialysis Solutions / chemistry
  • Humans
  • Kinetics
  • Male
  • Middle Aged
  • Models, Biological
  • beta 2-Microglobulin / blood
  • beta 2-Microglobulin / metabolism
  • beta 2-Microglobulin / pharmacokinetics*
  • beta 2-Microglobulin / therapeutic use


  • Hemodialysis Solutions
  • beta 2-Microglobulin