Clinical performance of a new high-flux synthetic membrane.

The clinical performance during first use of a new membrane manufactured from a blend of polyarylethersulfone and polyvinylpyrrolidone (Arylane; Hospal Renal Care, Lyon, France), in which the microstructure of the membrane has been tailored by the manufacturing process and polymer blend, has been compared with Fresenius Polysulfone (Fresenius Medical Care, Bad Homburg, Germany) in a prospective, randomized, crossover study. Small-molecular clearances were similar. A reduction in plasma beta(2)-microglobulin levels was present using both membranes, with a significantly greater removal by Arylane such that the mean postdialysis plasma level difference between the membranes at the end of dialysis was 8. 7 mg/L (95% confidence interval, 3.9 to 13.5; P = 0.004). Recovery of beta(2)-microglobulin from the dialysis fluid was similar: 170 +/- 70 mg for Arylane and 110 +/- 60 mg for Fresenius Polysulfone (P = 0.04). Both membranes were impermeable to albumin but allowed the passage of low-molecular-weight proteins, with 10,046 +/- 3,239 mg for Arylane and 7,285 +/- 2,353 mg for Fresenius Polysulfone recovered from the dialysis fluid (P = 0.07). Neutropenia and platelet adhesion to the membrane were minimal, and time-averaged complement levels during dialysis for C3a and C5b-9 were 207 +/- 92 and 62 +/- 24 ng/mL for Arylane and 223 +/- 68 and 45 +/- 24 ng/mL for Fresenius Polysulfone, respectively, and were membrane independent. This study indicates that the membrane using polyarylethersulfone in conjunction with PVP has complement-activation potential and neutropenia similar to Fresenius Polysulfone but has an enhanced capacity to remove beta(2)-microglobulin. This enhanced removal arises from transmembrane transport augmented by adsorption within the membrane matrix.