Clinical comparison of high-flux cellulose acetate and synthetic membranes

Abstract

Abstract Solute transport and alterations in complement and clotting induced by a new high-flux cellulose acetate membrane (CA-HF800-E, Diaphan®) were compared with those for cellulose triacetate (CTA) and polysulphone in a cross-over clinical study The membranes are similar in their small-molecule removal Serum β2-microglobulin decreased with all membranes but the decrease was independent of membrane type. Associated with β2-microglobulin removal was a protein loss which averaged 2636 mg for Diaphan®, 4937 mg for CTA, and 2500 mg for polysulphone. Albumin presence in the dialysate was less than the limit of detection (5mg/l) but for each of the membranes, occasional readings above the limit of detection were noted. C3a generation for Diaphan® is comparable with that for CTA and polysulphone, but differed for C5a and neutropenia. A highly significant correlation of the area under the concentration time curve of the two complement components was noted for the cellulose based membranes (r = 0.875, P = 0.0002 for Diaphan®, r = 0.823, P = 0.006 for CTA) this relationship was less marked for polysulphone (r = 0.396, P = 0.29) Induction of clotting characterized by the thrombin-antithrombin III (TAT) complex were similar for the three membranes, as were changes in platelet counts. Our findings indicate that while it is possible to modify cellulose to produce a membrane whose solute transport and biocompatibility is similar to synthetic membranes such as polysulphone, the structural modifications induce considerable differences in the amount of protein lost.