FP781RENALASE IN CHILDREN WITH CHRONIC KIDNEY DISEASE

Abstract

Introduction and Aims: Renalase is a catecholamines inactivating enzyme produced mainly by renal proximal tubule cells. Animal studies and studies in adults with kidney disease suggest that renalase may play role in pathogenesis of hypertension and target organ damage. The aim of the study was to assess level of renalase in children with chronic kidney disease and to find the relation between renalase level and clinical parameters in this group of patients. Methods: In 38 children (21 boys, 17 girls) aged from 4.91 to 18.0 mean: 12.23 64.19 years with chronic kidney disease we evaluated serum renalase level (Cloud Corp. WUHAN, China) [jig/mL], BMI Z-score, arterial stiffness parameters (pulse wave analysis, pulse wave velocity-PWV, Sphygmocor, AtCor Medical, Australia), peripheral and central blood pressure (Welch Allyn VSM 300 Patient Monitor, Welch Allyn, USA and Sphygmocor, respectively), intima-media thickness (IMT) (ALOKAProsound Alpha 6, ALOKA-Hitachi, Japan), medications used, kidney function (GFR ac. to Schwartz formula), and selected biochemical parameters. Control group included 38 healthy children (19 boys, 19 girls), aged from 5.51 to 18.00 mean 11.79 63.29 years. Results: In the study group GFR was from 4.19 to 85.55 mean 25.7468.94 mL/min/1.73 m2, 14 children were in stage G2 CKD, 11 in stage G3, 6 in stage G4 and 7 in stage G5 (6 children were dialysed: 5 were on peritoneal dialysis, 1 on hemodialysis); 26 chil-dren had arterial hypertension. Mean renalase level in the study group was from 0.93 to 114.16 mean 59.45623.25 [lg/mL] and was significantly higher compared to control group (27.2065.15 [ug/mL]) (p=0.0001). In children with CKD renalase level correlated with BMI Z-score (r=-0.36, p=0.027) and mean alphacalcidol dose [lg/24h] (r=0.41, p=0.02). In addition, in the study group we found significant correlations of renalase with GFR (r=-0.69, p=0.00001), hemoglobin (r=-0.48, p=0.002), phosphate (r=0.35, p=0.03), Calcium-phosphorus product (r=0.35, p=0.03), parathormone (r=0.58, p=0.0001), total cholesterol (r=0.35, p=0.03), LDL-cholesterol (r=0.36, p=0.03) and triglycerides (r=0.52, p=0.01). We found no correlations between rena-lase level and peripheral and central blood pressure and IMT ([cm] and Z-score); rena-lase level was significantly correlated with pulse wave velocity Z-score (r=0.42, p=0.043). In the control group renalase was correlated only with age (r=-0.37, p=0.022); such relation was not found in the study group. No other significant correlations between renalase and analyzed clinical, vascular and biochemical parameters were found in the control group. Conclusions: 1. In children with chronic kidney disease renalase level is higher compared to healthy peers and is highly dependent on glomerular filtration. 2. In children with chronic kidney disease renalase seems to be related neither to central nor to peripheral blood pressure but may be a marker of arterial stiffness.