title: Membrane flux not biocompatibility determines beta-2-microglobulin levels in hemodialysis patients.
abstract: BACKGROUND
  Serum beta(2)-microglobulin (beta(2)M) levels are important in dialysis-related amyloid deposition but can be influenced by dialysis technique.
  
  
  METHODS
  We measured beta(2)M levels in 3 centres using different dialysis regimes. Centre 1 (73 patients) used high-flux biocompatible, centre 2 (72 patients) low-flux biocompatible and centre 3 (142 patients) cuprophane dialysers.
  
  
  RESULTS
  beta(2)M levels were lower with high-flux biocompatible than with low-flux biocompatible or cuprophane dialysis (22.3 +/- 5.4 vs. 43.4 +/-13.7 and 37.6 +/-13.1 mg/l, respectively; p < 0.001). Levels were higher with low-flux biocompatible than with cuprophane dialysis (p < 0.001), but not if patients dialysed over 10 years were excluded. With low-flux biocompatible (47.4 +/- 9.8 vs. 38.7 +/- 15.2 mg/l; p < 0.01) and cuprophane dialysis (43.4 +/- 8.2 vs. 36.7 +/- 13.0 mg/l; p < 0.02), beta(2)M levels were higher in patients dialysed over 5 years than in those dialysed less. Despite beta(2)M levels increasing as residual renal function declined, there was no similar rise with high-flux biocompatible dialysis.
  
  
  CONCLUSIONS
  Techniques allowing significant convection maintain lower beta(2)M levels over many years. Membrane flux, not biocompatibility, is the main determinant of beta(2)M levels in routine practice.
authors.affiliation: Directorate of Medicine, Gloucestershire Royal Hospital, Gloucester, UK.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Pickett
authors.forename: Alastair
authors.initials: A
authors.lastname: Cruickshank
authors.forename: Roger N
authors.initials: RN
authors.lastname: Greenwood
authors.forename: David
authors.initials: D
authors.lastname: Taube
authors.forename: Andrew
authors.initials: A
authors.lastname: Davenport
authors.forename: Ken
authors.initials: K
authors.lastname: Farrington
mesh_terms: D000368:Aged; D000686:Amyloidosis / Q000209:etiology; D001672:Biocompatible Materials; D002482:Cellulose / Q000031:analogs & derivatives*; D003430:Cross-Sectional Studies; D017583:Hemodiafiltration; D006801:Humans; D008567:Membranes, Artificial; D008875:Middle Aged; D006435:Renal Dialysis / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D051437:Renal Insufficiency / Q000628:therapy; D001613:beta 2-Microglobulin / Q000097:blood*
chemical_list: D001672:Biocompatible Materials; D008567:Membranes, Artificial; D001613:beta 2-Microglobulin; D002482:Cellulose; C009865:cuprammonium cellulose