Objective: Neuron-specific enolase (NSE) and S-100B are brain-derived proteins, and their levels increase in brain injury. The aim of the study was to determine serum S-100B and NSE levels in patients with end-stage renal disease undergoing hemodialysis (HD) and peritoneal dialysis (PD) and to demonsrate how these levels were affected by the type of dialysis applied.

Methods: The study group consisted of age- and gender-matched 20 patients undergoing HD, 26 patients undergoing continuous ambulatory PD (CAPD) and 21 healthy controls. Blood samples were obtained before and after dialysis in the HD patient group, and fasting blood samples were obtained in the CAPD and control groups. The routine biochemical parameters were measured within two hours from all serum samples. The remaining serum samples were stored at -80 °C until the day of analysis of the S-100B and NSE assays. Serum S-100B and NSE levels were measured by chemiluminescence immunoassay method. Routine biochemistry tests were measured by colorimetric method using a biochemistry analyzer.

Results: Serum S-100B (0.11±0.06 ng/mL in HD, 0.13±0.09 ng/mL in CAPD and 0.05±0.03 ng/mL in controls) and NSE (12.7±5.99 ng/mL in HD, 9.26±5.52 ng/mL in CAPD and 6.82±2.36 ng/mL in controls) levels were higher in HD and CAPD groups compared to controls. S-100B and NSE levels were higher after HD compared to before HD (p<0.001). There was a weak but significant correlation between S-100B and NSE levels (r=0.290; p=0.006).

Conclusion: In this study, serum S-100B and NSE levels were found to be high in patients undergoing HD and PD. Serum S-100B and NSE concentrations were higher in HD and CAPD patients. Increased S-100B and NSE levels may be associated with cerebrovascular events in patients with chronic renal failure. They may also be important markers for the determination of cerebrovascular events.