Objective: On-line hemodiafiltration (OL-HDF) is a method that combines diffusive and convective solute transport component. OL-HDF provides improved solute clearance for both low-and large molecular-weight uremic toxins by enhancing convective clearance through highly permeable membranes. The aim of this study is to evaluate the effect of OL-HDF on oxidative stress and β2-microglobulin (β2-MG) in comparison with high-flux hemodialysis (HF-HD).
Methods: Twenty-one patients on thrice-weekly low-flux hemodialysis (LF-HD) for at least 6 months were studied. Every patient underwent OL-HDF and HF-HD for four weeks, respectively. There were 2 weeks of wash-out period in which patients were treated with LF-HD, between different treatment periods. Predialysis and postdialysis solute (creatinine, BUN, phosphate, β2-MG) concentrations were measured in the serum. In addition, predialysis solute (MDA, TAC, hsCRP) concentrations were measured.
Results: The urea reduction ratio (64.2±14.5 vs. 60.1±11.2%), Kt/V (1.4±0.2 vs. 1.3±0.3), β2-MG reduction ratio (53.8±9.7 vs. 44.3±8.7%) and β2-MG clearance (120.7±33.4 vs. 92.7±17.6 mL/min) were significantly higher in patients treated with on- line HDF compared with those treated with HF-HD. After 4 weeks of treatment, predialysis serum MDA levels were significantly lower in patients treated with OL-HDF compared with those treated with HF-HD (1.04±0.26 vs. 1.19±0.25 umol/L). After 4 weeks of treatment with 2 different dialysis modes, predialysis serum β2-MG (3.7±1.0 vs. 2.2±0.4 mg/ dL), MDA (1.19±0.21 vs. 1.04±0.26 umol/L), TAC (265.9±21.1 vs. 290.2±23.9 umol/L) and log hsCRP (0.07±0.51 vs. -0.23±0.62) levels were significantly improved compared to the baseline in OL-HDF patients. However, for HF-HD patients, only predialysis serum β2-MG level at 4 weeks was significantly lower than baseline (3.8±1.0 vs. 2.5±0.4 mg/dL).
Conclusion: This study shows that OL-HDF has been significant increase in oxidative stress and inflammatory marker removal compared to HF-HD.