Centralized on-line hemodiafiltration system utilizing purified dialysate as substitution fluid

We followed the guidelines of the Kyushu Society for Hemodiafiltration (HDF) Therapy on the purification of dialysate used as substitution fluid and clinically applied HDF using only 20 L or 15 L of substitution fluid in the pre- or postdilution mode, respectively. We used a centralized on-line HDF system consisting of a novel multi-patient dialysate delivery system applying 3 endotoxin (ET) removal filters in series, maintaining the ET level within the criteria limit below 1.0 IU/L (measured at the first filter outlet to be 0.1 IU/L and after the third filter to be below the sensitivity limit) irrespective of the fluctuation in the ET level of the tap water. Low molecular weight proteins (beta2-microglobulin, prolactin, alpha1-microglobulin, and alpha1-acid glycoprotein) were more effectively removed in this HDF system than in conventional hemodialysis (HD) using the same dialyzer as that in the HDF system, and the removal of these proteins in the HDF system was enhanced as their molecular weights increased. The clinical effect of the HDF system was demonstrated by a decrease in joint pain accompanied by improvement in joint motion in 6 dialysis patients followed over the long term (100 weeks).