Chronic kidney disease is associated with increased levels of renalase in serum and decreased in erythrocytes

Abstract

INTRODUCTION Renalase is a novel flavin adenine dinucleotide-dependent amine oxidase with catecholamine-degrading activity. The kidneys are the main source of this enzyme. OBJECTIVES In this study, we examined the concentrations of renalase in the serum, urine, and erythrocytes of patients with chronic kidney disease (CKD). PATIENTS AND METHODS We enrolled 155 white patients with CKD and 30 healthy controls. Renalase concentrations were measured using an enzyme-linked immunosorbent assay. RESULTS Serum renalase levels were higher in patients with CKD than in controls: median (Q1-Q3), 103 ng/ml (55.6-166 ng/ml) vs 17.7 ng/ml (16.3-21.8 ng/ml); P <0.001. Renalase levels in erythrocytes were lower in patients with CKD than in controls (median [Q1-Q3], 122 ng/ml [67.2-189 ng/ml] vs 254 ng/ml [166-293 ng/ml]; P <0.001). Urinary renalase levels did not differ between patients with CKD and controls (median [Q1-Q3], 147 ng/ml [102-193 ng/ml] vs 144 ng/ml [116-170 ng/ml]; P = 0.78). Urinary and erythrocyte renalase concentrations were negatively correlated with estimated glomerular filtration rate (eGFR). A multivariate general linear model analysis adjusted for age, sex, and eGFR of CKD patients showed that higher plasma dopamine and total protein concentrations were independent predictors of higher serum renalase levels (β = 0.32, P <0.001 and β = 0.25, P <0.001, respectively). CONCLUSIONS Our results indicate that serum renalase concentrations are elevated in patients with CKD, whereas renalase concentrations in urine and erythrocytes are correlated with impaired kidney function.

Renalase in Haemodialysis Patients with Chronic Kidney Disease

“…Erythrocytes, being nuclear-free cells without mitochondria, do not carry out classical metabolism and, therefore, are a very good "transporter" of many substances. Previous studies have shown that the concentration of renalase is significantly increased in patients with chronic kidney disease (CKD), and additional studies have demonstrated that this change is correlated with disease severity [8][9][10][11]. Patients with CKD characteristically display a high level of anaemia that is mainly associated with impaired erythropoietin production, although haemolysis and a significantly shortened erythrocyte survival time have also been implicated [12,13].…”

“…In our previous study, we examined renalase concentrations in CKD patients with preserved renal function [11]. Renalase serum concentrations correlated negatively with parameters of kidney function.…”

“…The control group included 30 healthy subjects, with normal kidney function (normal GFR values and normal creatinine serum levels) [11]. The GFR was estimated using the CKD-EPI equation (eGFR).…”

“…The results of some studies suggest that patients with CKD have lower levels of renalase in serum, while others suggest that CKD patients have increased levels of renalase [1,[8][9][10]. In the previous work, we studied renalase concentrations in CKD patients with preserved renal function and correlated with parameters of kidney function [11]. Patients with end-stage kidney disease most often suffer from anuria and require hemodialysis, which changes many biochemical parameters.…”

Associations between renalase concentration and the occurrence of selected diseases

“…Wiśniewska et al presented corresponding conclusions concerning the group of patients with CKD, among whom serum renalase concentration was significantly higher than in the control group. Also, the measurement of renalase in erythrocytes was performed and showed a decrease in renalase and an increase in urea concentration in the control group [37]. All of these studies used the ELISA technique to determine plasma renalase concentration.…”