title: Role of residual kidney function and convective volume on change in beta2-microglobulin levels in hemodiafiltration patients.
abstract: OBJECTIVE
  Removal of beta2-microglobulin (beta2M) can be increased by adding convective transport to hemodialysis (HD). The aim of this study was to investigate the change in beta2M levels after 6-mo treatment with hemodiafiltration (HDF) and to evaluate the role of residual kidney function (RKF) and the amount of convective volume with this change.
  
  
  METHODS
  Predialysis serum beta2M levels were evaluated in 230 patients with and 176 patients without RKF from the CONvective TRAnsport STudy (CONTRAST) at baseline and 6 mo after randomization for online HDF or low-flux HD. In HDF patients, potential determinants of change in beta2M were analyzed using multivariable linear regression models.
  
  
  RESULTS
  Mean serum beta2M levels decreased from 29.5 +/- 0.8 (+/-SEM) at baseline to 24.3 +/- 0.6 mg/L after 6 mo in HDF patients and increased from 31.9 +/- 0.9 to 34.4 +/- 1.0 mg/L in HD patients, with the difference of change between treatment groups being statistically significant (regression coefficient -7.7 mg/L, 95% confidence interval -9.5 to -5.6, P < 0.001). This difference was more pronounced in patients without RKF as compared with patients with RKF. In HDF patients, beta2M levels remained unchanged in patients with GFR >4.2 ml/min/1.73 m2. The beta2M decrease was not related to convective volume.
  
  
  CONCLUSIONS
  This study demonstrated effective lowering of beta2M levels by HDF, especially in patients without RKF. The role of the amount of convective volume on beta2M decrease appears limited, possibly because of resistance to beta2M transfer between body compartments.
authors: Department of Nephrology, VU Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands. pm.terwee@vumc.nl
authors: E Lars
authors: EL
authors: Penne
authors: Neelke C
authors: NC
authors: van der Weerd
authors: Peter J
authors: PJ
authors: Blankestijn
authors: Marinus A
authors: MA
authors: van den Dorpel
authors: Muriel P C
authors: MP
authors: Grooteman
authors: Menso J
authors: MJ
authors: Nubé
authors: Piet M
authors: PM
authors: Ter Wee
authors: Renée
authors: R
authors: Lévesque
authors: Michiel L
authors: ML
authors: Bots
mesh_terms: D000368:Aged; D005260:Female; D017583:Hemodiafiltration / Q000379:methods; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D001613:beta 2-Microglobulin / Q000097:blood*
chemical_list: D001613:beta 2-Microglobulin