High-flux synthetic versus cellulosic membranes for beta 2-microglobulin removal during hemodialysis, hemodiafiltration and hemofiltration.

Efficient removal of beta 2 microglobulin (beta 2-M) in end-stage renal failure patients is a continuing preoccupation, as the incidence and severity of dialysis-associated amyloidosis are increasing. To evaluate comparative beta 2-M removal we studied six stable end-stage renal failure patients during high-flux 3-h haemodialysis, haemodia-filtration, and haemofiltration, using acrylonitrile, cellulose triacetate, polyamide and polysulphone capillary devices. The reduction of plasma beta 2-M, total removal in ultrafiltrate/dialysate, and beta 2-M sieving coefficients were measured by RIA. The results suggest that convection plays the major role in beta 2-M removal when high-flux synthetic membranes are used in combination with high blood flow rates. In contrast, using the cellulose triacetate membrane under investigation, beta 2-M removal is diminished when ultrafiltration rates are increased. Accordingly, in any future prospective study on the role of beta 2-M retention in the amyloidogenesis, it is recommended that high-flux synthetic membranes be employed rather than the type of high-flux cellulosic membranes used in this study. The modality with which these synthetic membranes are used is probably less important, as long as maximum convective transport rates are obtained. Under present conditions, this will imply haemofiltration or haemodiafiltration rather than haemodialysis.