Clinical effect of pre-dilution hemodiafiltration based on the permeation of the hemodiafilter.

The removal characteristics of on-line pre-dilution hemodiafiltration (HDF) were compared with those of hemodialysis using so-called 'super high-flux' or 'class V' dialyzers. A strong correlation between the reduction rate (RR) of α1-microglobulin (MG) and relief of clinical symptoms was found. The treatment conditions, including flow rates as well as selection of diafilter performance, were determined in consideration of the target symptoms to be removed and the target RR of α1-MG or, alternately, the albumin loss. An RR of β2-MG >80% corresponded to that of α1-MG being >35% in both modalities, and these numbers were more easily achieved by employing on-line pre-dilution HDF, rather than hemodialysis with super high-flux dialyzers. In some situations, however, albumin loss of 6 g or more may be admissible when a patient shows severe clinical symptoms, such as restless legs syndrome. HDF with a large amount of fluid exchange and a large amount of albumin loss is worth trying, as long as the albumin loss is controlled in a measured manner.