Background: Oxidative stress profoundly influences the biochemistry of proteins and many other molecules in tissues of uremic patients. In three different groups of uremic patients, the concentrations of the free and bound pentosidine and low-molecular-weight-advanced glycoxydation end products (LMW-AGEs), carbonyls (LMW-C), advanced oxidation protein products (AOPP) and the total antioxidant power of serum were studied in order to determine the relationships between these factors in hemodialytic and transplanted patients.
Patients and methods: The above-mentioned parameters were determined in 10 subjects who were currently in hemodialysis (HD) treatment, 10 kidney transplanted patients with chronic renal failure (Tx-CRF), 10 kidney transplanted patients with normal renal function (Tx-N) and 10 healthy subjects (Ctr). The data matrix (40x7) was analyzed using the principal component analysis (PCA).
Results: AGEs, carbonyls and AOPP were strongly correlated, while the total antioxidative serum capacity was not related to the other oxidative stress parameters. All the oxidative stress-related parameter values (AGEs, AOPP and LMW-C) in the Tx patients were similar to those of the control group, but were higher in the patients with chronic renal failure.
Conclusions: The correlation between early and advanced oxidative stress markers indicates that reactive oxygen species are involved in a common step in the mechanism of protein modification in all the patient examined. The relationships between carbonyls and AGEs (free, bound pentosidine and LMW-AGEs) support the hypothesis of "carbonyl stress". The common mechanism of the formation of oxidation products in healthy and diseased subject suggests their role of detoxification within kidney function. The total antioxidant power of the serum is not related to the other parameters, which indicates a possible role of molecule interfering.