title: Relative importance of residual renal function and convection in determining beta-2-microglobulin levels in high-flux haemodialysis and on-line haemodiafiltration.
abstract: BACKGROUND
  Convective blood purification improves beta(2)-microglobulin (beta(2)M) removal and may delay the onset of dialysis-related amyloidosis. We assessed the differential effects of high-flux haemodialysis (HD) and on-line haemodiafiltration (HDF) on plasma beta(2)M levels, given the enhanced convective capability of HDF.
  
  
  METHODS
  We measured pre-dialysis beta(2)M levels in 297 patients in a programme employing both high-flux HD and HDF, then analysed the relationship of beta(2)M to modality and other variables.
  
  
  RESULTS
  Independent determinants of plasma beta(2)M levels were residual renal function, age, HD vintage, and C-reactive protein load, but not the patient's predominant modality (high-flux HD or HDF). Patients with KRU levels <0.5 ml/min had significantly higher beta(2)M levels than patients with KRU between 0.5 and 1 ml/min.
  
  
  CONCLUSIONS
  Residual renal function is of overriding importance as a determinant of beta(2)M levels in HD patients and may supersede enhanced convective clearance by HDF. Beneficial effects extend to very low levels of residual renal function.
authors.affiliation: Renal Unit, Lister Hospital, Stevenage, UK. andyfry@doctors.org.uk
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Fry
authors.forename: Dhruv K
authors.initials: DK
authors.lastname: Singh
authors.forename: Shahid M
authors.initials: SM
authors.lastname: Chandna
authors.forename: Ken
authors.initials: K
authors.lastname: Farrington
mesh_terms: D000328:Adult; D000368:Aged; D000686:Amyloidosis / Q000209:etiology / Q000517:prevention & control; D002097:C-Reactive Protein / Q000032:analysis; D018481:Convection; D005260:Female; D017583:Hemodiafiltration / Q000009:adverse effects / Q000379:methods; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy; D007677:Kidney Function Tests; D008297:Male; D008567:Membranes, Artificial; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D011108:Polymers; D006435:Renal Dialysis / Q000009:adverse effects / Q000379:methods; D012212:Rheology; D013450:Sulfones; D013997:Time Factors; D014508:Urea / Q000097:blood; D001613:beta 2-Microglobulin / Q000032:analysis*
chemical_list: D008567:Membranes, Artificial; D011108:Polymers; D013450:Sulfones; D001613:beta 2-Microglobulin; C017662:polysulfone P 1700; D014508:Urea; D002097:C-Reactive Protein