Plasma oxalic acid as a trigger for oxidative processes in end-stage renal disease patients

Abstract

The present study aimed to evaluate the changes in oxidative stress markers according to the concentration of plasma oxalic acid (POx) in end-stage renal disease (ESRD) patients.
 Methods. We conducted a cross-sectional observational study involving 72 ESRD patients and 30 relatively healthy individuals who served as a control reference group for evaluation of POx concentration. Among ESRD patients there were 32 hemodialysis (HD) patients and 40 peritoneal dialysis (PD). POx concentration was measured spectrophotometrically using a commercially available kit (MAK315, Sigma, Spain). Malonic dialdehyde (MDA), ceruloplasmin (CP), transferrin (TR), sulfhydryl groups (SH-groups), antioxidant blood capacity (AOC) and total peroxidase activity of erythrocytes (TPA) were measured and the oxidative stress index (OSI) was calculated in all examined patients.
 Results. A significant increase in POx concentration was observed in ESRD patients compared with healthy volunteers (p < 0.0001). The concentrations of MDA in serum, OSI in erythrocytes and serum of the examined patients were gradually increased, while serum levels of CP, AOC, SH-groups and TPA in erythrocytes, on the contrary, were decreased in accordance with the increasing trend of POx concentrations. Correlation analysis demonstrated a statistically significant direct relationship between POx concentration and MDA (r = 0.57; p <0.0001) and OSI (r = 0.64; p <0.0001). The inverse correlation was determined between POx and antioxidant markers: CP (r = -0.35; p = 0.007), SH-groups in serum (r = -0.3; p = 0.04) and erythrocytes (r = -0.53 ; p <0.0001).
 Conclusions. The intensity of oxidative-antioxidant balance disorders in the blood of ESRD patients has been associated with the POx concentration: the higher the concentration of POx was the more active oxidative processes and the more pronounced lack of antioxidant protective factors occurred. Further studies are needed to determine the role of POx in the initiation of oxidative stress and chronic inflammation in ESRD patients.

Oxalate Balance in Peritoneal Dialysis Patients: A Potential Role of Dialysis-related Peritonitis

“…In accordance with previous results, the present study demonstrated that UOx excretion or overall oxalate removal levels in all PD patients were within reference intervals for healthy subjects and similar to the previously reported average of UOx excretion in ESKD patients (3,5,6,8,13,35). Nonetheless, the levels of urine output in the participants of the present study were at least four times lower than those of healthy subjects (2,35), meaning that PD patients had hyperoxaluria.…”

“…Notwithstanding these limitations, our study is the first to our knowledge that reports a strong association between dialysis-related peritonitis and elevated POx in PD patients. Although the clinical significance of hyperoxalemia in PD patients remains unclear, recent studies have demonstrated that oxalate is involved in the activation of oxidative stress, chronic inflammation, and atherogenesis (1,8,9,11), which may explain the high cardiovascular and overall mortality in PD-related peritonitis. Quite possible that further research to investigate the effect of dietary oxalate restriction or the gut microbiota correction may open up a new pathway to improve PD-related peritonitis outcomes.…”

Pleiotropic effects of atorvastatin in peritoneal dialysis patients: A retrospective-prospective observational cohort study

“…Подібні риси патогенезу атеросклерозу та ХХН, які включають ендотеліальну дисфункцію та хронічне запалення продемонстровані багатьма попередніми дослідженнями [6,[32][33][34][35]. Регулювання будь-якого з цих патогенетичних шляхів може пояснити визначене зниження інтраперитонеальної продукції прозапальних цитокінів у ПД пацієнтів, які приймали аторвастатин.…”

Chronic inflammation and progression of chronic kidney disease in patients with type 2 diabetes

“…ХХН у пацієнтів з ЦД може бути наслідком численних супутніх недіабетичних захворювань нирок, а саме -макросудинної ангіопатії, інтерстиціального нефриту через токсичний вплив лікарських засобів, рецидивуючої інфекції сечової системи, тощо [1,[31][32][33][34][35]. ХХН є стадійним процесом, який ініціюється впливом різноманітних екзогенних та ендогенних факторів, що приймають участь у прогресуванні ренального пошкодження з формуванням нефросклерозу [36,37]. Слід зазначити, що близько у 47% хворих на ЦД 2 типу ХХН є не діагностованою [38,39].…”