Dynamics of salivary markers of kidney functions in acute and chronic kidney diseases

Abstract

Saliva can be used as an alternative diagnostic fluid enabling easy and non-invasive disease monitoring. Urea and creatinine can be measured in saliva and both were shown to be increased in renal failure. However, the dynamics of these markers during the development of kidney diseases is unknown. We aimed to describe the dynamics of salivary urea and creatinine in various animal models of acute kidney injury (AKI) and chronic kidney disease (CKD) and in patients with different stages AKI or CKD. Ninety Wistar rats underwent bilateral nephrectomy (BNX), ischemia–reperfusion injury (IRI) or glycerol-induced kidney injury to model AKI. CKD was modelled using 5/6 nephrectomy. In the clinical part 57 children aged 12.6 ± 4.9 years with AKI (n = 11) or CKD (n = 46) and 29 healthy controls (aged 10.2 ± 3.7 years) were enrolled. Saliva and blood samples were collected in both, animal experiments and the human study. In animal models of AKI, plasma urea and creatinine were higher than in controls. An increase of salivary urea and creatinine (twofold) was observed in BNX and IRI, but only after 12 h and 24 h, respectively. In glycerol nephropathy and 5/6 nephrectomy, salivary urea increased (by 100% and by 50%), while salivary creatinine did not change during the observation period. Salivary urea and creatinine were significantly higher in all patients compared to controls (threefold) and in both, AKI and CKD they were associated with the severity of renal failure. Plasma and salivary concentrations correlated only in children with renal failure (R = 0.72 for urea; R = 0.93 for creatinine), but not in controls (R = -0.007 for urea; R = 0.02 for creatinine). Our study indicates that during the development of renal impairment saliva could be used for non-invasive monitoring in higher stages of AKI or CKD, rather than for screening of early stages of kidney diseases.

Determinants of Outcomes of Acute Kidney Injury: Clinical Predictors and Beyond

“…Recently, many kidney damage-associated biomarkers that may be able to predict an AKI episode have been extensively reviewed, including Chitinase 3-like protein 1 (CHI3L1), Neutrophil gelatinase-associated lipocalin (NGAL), Kidney injury molecule-1, Liver fatty acid binding protein (L-FABP), osteopontin, hemojuvelin and interleukins [ 99 , 100 , 101 , 102 , 103 , 104 ].…”

Antidepressant Potential of a Functionalized 3-Selanyl Benzo[b]Furan Compound in Mice: Focus on the Serotonergic System

“…Plasma biochemical analyses showed that SeBZF 3 did not cause changes in ALT and AST activities or urea levels as compared to the control group (Figure S1A–C). Certain chemical safety of SeBZF 3 is supposed from these assessments since their elevation can denote hepatocellular and kidney damage, respectively.…”

“…Plasma biochemical analyses showed that SeBZF3 did not cause changes in ALT and AST activities or urea levels as compared to the control group (Figure S1A−C). Certain chemical safety of SeBZF3 is supposed from these assessments since their elevation can denote hepatocellular 45 and kidney damage, 46 respectively. In addition, parameters generally sensible to hazardous chemicals such as the body weight of the animals (Figure S1D), food intake (Figure S1E), and water consumption (Figure S1F) also remained without significant variations between the groups (Figure S1D).…”

A saliva urea test strip for use in feline and canine patients: a pilot study

“…18 Previous work in humans determined that serum urea must meet a minimum threshold level before it diffuses into the saliva. 10 This may explain why the correlation coefficient was found to be moderate, but the test strip still performed well in detecting serum urea above the upper limit of the RI. Once the threshold is reached, urea begins to diffuse significantly into the saliva where it is detected by the saliva test strip to signal that azotemia is present.…”