Effects of medium cut-off dialysis membranes on inflammation and oxidative stress in patients on maintenance hemodialysis

Purpose: Medium cut-off membranes were developed for providing increased clearance of larger middle-molecule uremic toxins. We compared the effect of low-flux, medium cut-off, and high-flux membranes on chronic inflammation and oxidative stress in patients with maintenance hemodialysis. Methods: A total of 42 patients were enrolled in this study. Total antioxidant status, total oxidant status, paraoxonase-1, ischemia-modified albumin, total Thiol, disulfide bond, and native Thiol were measured to determine oxidative stress. C-reactive protein was measured to define inflammation. Results: 37% of the total patients were females, and the mean age was 52.9 ± 16 years. Serum albumin and Kt/V were similar between groups during the study period. We did not find any significant difference at baseline in the 3rd and 6th months of the study when we compared the inflammatory marker and oxidative indicator levels between three hemodialysis membranes in the whole study group. In the subgroup analysis of 19 patients with a high C-reactive protein level, we found that the medium cut-off membrane significantly reduced serum C-reactive protein level, when compared to low-flux and high-flux membrane [2.8 mg/L vs. 13.7 mg/L and 6.1 mg/L, respectively, p = 0.05]. However, we did not find a significant change in oxidative stress indicators in patients with high C-reactive protein levels between the three dialysers. Conclusion: The medium cut-off membrane has favorable effects on inflammation in patients with maintenance hemodialysis. However, this positive effect could not be demonstrated in oxidative stress.