title: A new synthetic dialyzer with advanced permselectivity for enhanced low-molecular weight protein removal.
abstract: Optimizing solute removal at minimized albumin loss is a major goal of dialyzer engineering. In a prospective, randomized, crossover study on eight patients (age 63 +/- 14 years) on maintenance hemodialysis, the new Baxter Xenium 170 high-flux dialyzer (BX), which contains a 1.7-m(2) PUREMA H dialysis membrane, was compared with two widely used reference high-flux dialyzers currently available for hemodialysis in North America, the Fresenius Optiflux 180 NR (FO) and the Gambro Polyflux 170 H (GP). Solute removal and biocompatibility were assessed in hemodialysis for 240 min at blood and dialysate flow rates of 300 and 500 mL/min, respectively. Additional ex vivo experiments detecting the interleukin-1beta (IL-1b) generation in recirculated donor blood were performed to demonstrate the pyrogen retention properties of the dialyzers. The instantaneous plasma clearances were similar for the three dialyzers except for cystatin c (cysc), for which a lower clearance was measured with FO as compared with BX and GP after 30 and 180 min of hemodialysis. The reduction ratios (RRs) corrected for the hemoconcentration of beta(2)-microglobulin and cysc were lower in FO (44 +/- 9 and 35 +/- 9%, respectively) versus BX (62 +/- 6 and 59 +/- 7%, respectively) and GP (61 +/- 7 and 56 +/- 8%, respectively). The RRs of the cytokine tumor necrosis factor alpha and interleukin-6 were not different between the dialyzers. The albumin loss was <300 mg for all filters. No differences between the dialyzers were found in the biocompatibility parameters showing very low leukocyte and complement activation. The ex vivo recirculation experiments revealed a significantly higher IL-1b generation for GP (710 +/- 585 pg/mL) versus BX (317 +/- 211 pg/mL) and FO (151 +/- 38 pg/mL). BX is characterized by a steep solute sieving profile with high low-molecular weight protein removal at virtually no albumin loss and an excellent biocompatibility. This improved performance may be regarded as a contribution to optimal dialysis therapy.
authors.affiliation: University of Würzburg, Department of Medicine, Division of Nephrology, Würzburg, Germany. krieter_d@medizin.uni-wuerzburg.de
authors.forename: Detlef H
authors.initials: DH
authors.lastname: Krieter
authors.forename: Horst-Dieter
authors.initials: HD
authors.lastname: Lemke
authors.forename: Christoph
authors.initials: C
authors.lastname: Wanner
mesh_terms: D000368:Aged; D018592:Cross-Over Studies; D015891:Cystatins / Q000097:blood; D005260:Female; D006801:Humans; D053583:Interleukin-1beta / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy*; D008297:Male; D008422:Materials Testing; D008567:Membranes, Artificial; D008875:Middle Aged; D008970:Molecular Weight; D010539:Permeability; D011446:Prospective Studies; D011749:Pyrogens / Q000097:blood*; D006435:Renal Dialysis / Q000295:instrumentation*; D012709:Serum Albumin; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D001613:beta 2-Microglobulin / Q000097:blood
chemical_list: D015891:Cystatins; D053583:Interleukin-1beta; D015850:Interleukin-6; D008567:Membranes, Artificial; D011749:Pyrogens; D012709:Serum Albumin; D014409:Tumor Necrosis Factor-alpha; D001613:beta 2-Microglobulin