EXPRESS: Differential oxidative stress profiles in nephrolithiasis and ureterolithiasis: biochemical insights from serum and urinary markers

Urolithiasis, characterized by the formation of stones within the urinary tract, poses a significant medical challenge influenced by multifactorial origins including genetic predisposition, diet, and lifestyle factors. This condition predominantly affects males and exhibits varying prevalence rates across different global regions. Oxidative disturbances have been implicated in urolithiasis pathogenesis through mechanisms involving renal inflammation and tissue damage. This study investigated serum and urinary redox markers in 107 patients with kidney or ureteral stones versus 80 healthy controls. To the best of our knowledge, this represents the initial investigation comparing oxidative stress levels in the serum and urine of patients afflicted with nephrolithiasis and ureterolithiasis. We observed significantly elevated levels of advanced oxidation protein products (AOPP, p<0.01), malondialdehyde (MDA, p<0.001), total oxidant status (TOS, p<0.001), and oxidative stress index (OSI, p<0.001) in serum of urolithiasis patients, alongside decreased total antioxidant capacity (TAC, p<0.001). There were no differences in thiol group and Amadori products concentrations between studied groups. Moreover, increased concentration of AOPP (p<0.001), TOS (p<0.01) and OSI (p<0.01) as well as decreased level of TAC (p<0.001) was observed in urine of urolithiasis patients. Distinct patterns of oxidative stress markers were observed between nephrolithiasis and ureterolithiasis subgroups, underscoring differential oxidative stress profiles in these conditions. These findings may support early diagnosis, risk stratification, and personalized management of urolithiasis patients by revealing distinct oxidative stress profiles associated with stone location (renal vs ureteral).