Oxidative Stress in the Pathophysiology of Kidney Disease: Implications for Noninvasive Monitoring and Identification of Biomarkers

Table 2

Overview of clinical studies evaluating the potential of salivary and/or urinary markers of oxidative stress in patients with renal diseases.

Patient	Marker	Result	Biofluid	Reference
ESRD with DM on dialysis; ESRD without DM on dialysis; CKD with DM; CKD without DM; Healthy controls	UA, SOD; TAC, Px	↓ UA in saliva after dialysis in CKD patients with or without DM	Unstimulated saliva (salivary flow rate)	2007; nonsmokers; [93]
Predialysis CKD patients; ESRD on dialysis	UA, TAC; SOD, Px	↓ UA and ↑ peroxidase in saliva of ESRD patients on dialysis vs. predialysis CKD patients	Unstimulated saliva (salivary flow rate)	2008; nonsmokers; [94]
CKD patients; ESRD on dialysis; Healthy controls	NO	↑ NO in saliva of CKD patients and ESRD on dialysis	Saliva	2015; [89]
ESRD on dialysis (more than 6 months); Healthy controls	NO	↑ NO in saliva of ESRD patients; ↓ NO in saliva after dialysis	Filtered saliva	2018; nonsmokers; [91]
Pediatric patients with CKD; Healthy controls	UA, CAT, SOD, Px, GSH, TAC, TOS, OSI, AGEs, AOPP, MDA	↑ Concentrations of UA, SOD, GSH, AGEs, AOPP, and MDA in unstimulated and stimulated saliva of CKD patients vs. controls; Salivary AOPP—robust marker of CKD	Unstimulated saliva; Stimulated saliva (salivary flow rate)	2018; [95]
ESRD patients on dialysis; Healthy controls	NO	↑ NO in saliva of ESRD patients vs. controls; ↓ NO in saliva after dialysis	Unstimulated saliva	2018; nonsmokers; [90]
Pediatric patients with CKD; Healthy controls	FRAP, UA; UA-independent FRAP	↑ FRAP in stimulated saliva and urine of CKD patients vs. controls	Unstimulated saliva; Stimulated saliva; Urine	2019; [100]
Liver transplantation patients; Baseline; 2 hours after graft reperfusion; 24 hours after transplantation	MDA, H2O2; 6-keto-prostaglandin F1α, 8-keto-prostaglandin F2α	↑ Concentrations of all measured markers in patients with AKI following transplantation	Urine	2014; [101]

ESRD: end-stage renal disease; DM: diabetes mellitus; CKD: chronic kidney disease; UA: uric acid; SOD: superoxide dismutase; TAC: total antioxidant status; Px: peroxidase; NO: nitric oxide; CAT: catalase; GSH: glutathione; TOS: total oxidant status; OSI: oxidative stress index; TAC: total antioxidant capacity; AGEs: advanced glycation end products; AOPP: advanced oxidation protein products; MDA: malondialdehyde.