title: A new polymethylmethacrylate membrane for hemodialysis.
abstract: High molecular weight (MW) solutes are not removed during conventional hemodialysis (HD), and their accumulation is thought to play a role in some long-term HD complications (anemia, bone and joint pain, neuropathy, itching). The present trial was conducted to evaluate the removal capacity during in vivo HD of a new polymethylmethacrylate (PMMA) membrane (Filtryzer BK-F, 1.3 m2) compared to conventional PMMA (BK-P, 1.6 m2) and to cellulose acetate (CA, 1.3 m2). BK-F dialyzers, with a pore size of 100 A degrees and 62% porosity, are designed to remove high MW substances. Ten stable anuric RDT patients (53 +/- 13 years) were treated for one week with each membrane in a randomized sequence. Plasma concentrations of creatinine, BUN and beta 2-microglobulin (beta 2-M) were measured before (b) and after (a) HD to determine the reduction rate for these substances (%). Beta 2-M concentration after HD was corrected for changes in distribution volume. Samples of spent dialysate were collected after 3 minutes, 120 minutes and at the end of HD sessions, and appropriately treated and concentrated for HPLC analysis. The reduction rate for BUN and creatinine was similar for the 3 membranes. BK-F showed a higher beta 2-M reduction rate than BK-P (p < 0.005) or CA (p < 0.0001). HPLC analysis of dialysate showed prevalent peaks < 4 kilodaltons (kDa) throughout HD for BK-P and CA. Solutes > 10 kDa were infrequently detected. Peak profile during HD with BK-F was quite different, showing a predominant peak > 50 kDa which also included albumin. However, albumin loss significantly decreased after 120 minutes and at the end of dialysis compared with the 3-minute values, and was lower than that reported in CAPD patients. With BK-F a peak of MW > 500 kDa was also detected which previous studies indicated as a range characterized by the presence of erythropoiesis inhibitors. Use of the BK-F membrane in HD could afford satisfactory removal of high MW substances, thereby preventing or controlling some long-term HD complications such as anemia or beta 2-M amyloid formation.
authors.affiliation: Institute of Nephrology, G. D'Annunzio University, Chieti, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Bonomini
authors.forename: B
authors.initials: B
authors.lastname: Fiederling
authors.forename: T
authors.initials: T
authors.lastname: Bucciarelli
authors.forename: V
authors.initials: V
authors.lastname: Manfrini
authors.forename: C
authors.initials: C
authors.lastname: Di Ilio
authors.forename: A
authors.initials: A
authors.lastname: Albertazzi
mesh_terms: D000328:Adult; D000368:Aged; D001672:Biocompatible Materials; D001806:Blood Urea Nitrogen; D002482:Cellulose / Q000031:analogs & derivatives; D016009:Chi-Square Distribution; D002851:Chromatography, High Pressure Liquid; D003404:Creatinine / Q000097:blood; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000628:therapy*; D008297:Male; D008567:Membranes, Artificial; D008768:Methylmethacrylates; D008875:Middle Aged; D008970:Molecular Weight; D010531:Peritoneal Dialysis, Continuous Ambulatory / Q000592:standards; D006435:Renal Dialysis / Q000592:standards*; D012709:Serum Albumin / Q000378:metabolism; D012984:Software; D016896:Treatment Outcome; D001613:beta 2-Microglobulin / Q000378:metabolism
chemical_list: D001672:Biocompatible Materials; D008567:Membranes, Artificial; D008768:Methylmethacrylates; D012709:Serum Albumin; D001613:beta 2-Microglobulin; C005062:acetylcellulose; D002482:Cellulose; D003404:Creatinine