Hepcidin, Selenium and Superoxide Dismutase in Oxidative Stress and in Dialysis Patients

Chronic kidney diseases (CKDs) are characterized by complex changes in cellular metabolism, leading to oxidative stress (OS), i.e. increased production of oxidative radicals (OR), which can play a key role in a number of clinical complications of this pathology. Trace elements selenium (Se), copper (Cu) and zinc (Zn) play a major role in the antioxidant defense system. The antioxidant enzymes are superoxide dismutases (SODs), catalases (CATs) and glutathione peroxidases (GSHPxs). We evaluated serum hepcidin, plasma selenium concentrations and the superoxide dismutase activity in 59 CKD patients on hemodialysis. Patients were monitored at University Hospital “Aleksandrovska”, Clinic of Dialysis Treatment and Clinic of Nephrology. The results were compared with a matched by sex and age control group. Serum hepcidin and SOD activity were determined by ELISA method.Plasma selenium concentration was examined with the help of AAS (Perkin-Elmer). We determined CBC (using hematology analyzer ADVIA 2120, Siemens Healthcare) and biochemical parameters (on automatic analyzer Dimension RxL MAX, Siemens Healthcare) of all participants. The serum iron and TIBC levels were determined by AAS (Perkin-Elmer). For statistical analysis of the results we used Student's paired t-test and Pearson's correlation. We found a statistically significant higher serum hepcidin levels in CKD patients on chronic dialysis (356.6 μg/L ± 52.5 μg/L) compared to the control group (19.4 μg/L ± 2.7 μg/L; P<0.001). Plasma selenium levels and SOD activity were decreased in CKD patients on on chronic dialysis (422.6 nmol/L ± 51.1 nmol/L; 45.3 μg/mL ± 6.8 μg/mL) compared to the control group (847.5 nmol/L ± 75.4 nmol/L; 101.6 μg/mL ± 10.9 μg/mL; P<0.001). The presence of anemic syndrome and oxidative stress are indisputable pathological conditions accompanying chronic kidney diseases. A significant percentage of patients on dialysis are with abnormal levels of certain important trace elements - Zn, Se, Cu, and magnesium and one recently discovered regulator of iron metabolism - hepcidin, and between all of the following conditions are found interconnections and influences.