Role of residual kidney function and convective volume on change in beta2-microglobulin levels in hemodiafiltration patients.
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.
Penne
E Lars
EL
Department of Nephrology, VU Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands. pm.terwee@vumc.nl
van der Weerd
Neelke C
NC
Blankestijn
Peter J
PJ
van den Dorpel
Marinus A
MA
Grooteman
Muriel P C
MP
Nubé
Menso J
MJ
Ter Wee
Piet M
PM
Lévesque
Renée
R
Bots
Michiel L
ML
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*
D001613:beta 2-Microglobulin