URINARY SE-CADHERIN AND PLASMA CYSTATIN C AS NOVEL BIOMARKERS OF DIABETIC NEPHROPATHY

Abstract

Background and aim : Diabetes is a major cause of chronic kidney disease (CKD). Urine albumin and estimated glomerular filtration rate (eGFR) are the two key markers for chronic kidney disease (CKD). The aim of our work was to explore the possibility of plasma cystatin C and urinary sE.cadherin as useful biomarkers for early detection of diabetic nephropathy (DN).
Methods: - A total number of 80 subjects were included and were classified into three main groups. Group I (20) normal subjects with no history of DM, hypertension or other diseases and with albumin / creatinine (Alb / Cr) ratio below 30 mg/ g. Group II (30) type 2 diabetic patients with Alb / Cr ratio below 30 mg/ g. Group III (30) type 2 diabetic patients with Alb / Cr ratio between 30 and 300 mg/ g. The latter two groups were divided in two sub groups A and B according to GFR by MDRD: normal (≥ 90 ml /min / 1.73 m2) and < 90 ml /min / 1.73 m2. All subjects underwent urine analysis, complete blood picture, liver function tests, kidney function tests, INR, fasting plasma glucose level, HbA1c, lipid profile, abumin/creatinine ratio, pelvi-abdominal ultrasound, plasma Cystatin C and urinary human sE-Cadherin.
Results: - Plasma cystatin C and urinary sE.cadherin/ cr levels were increased with micro-albuminuria. Also, plasma cystatin C and urinary sE.cadherin/ cr levels were significant between normoalbuminuric subjects with GFR ≥ 90 mL/min/1.73 m2 calculated by the MDRD equation and those below 90 mL/min/1.73 m2 being higher in the later. In multivariate logistic analysis, plasma cystatin C level was the only independent factor associated with eGFR < 90 mL/min/1.73m2 estimated by MDRD equation in patients with normoalbuminuria. There are high significant positive correlations of plasma cystatin C with age, total cholesterol unlike urinary sE.cadherin/ cr, but both had positive correlations with serum Cr, blood urea and Alb / Cr ratio and negative correlations with GFR.
Conclusion and Recommendations:- Plasma cystatin C and urinary sE.cadherin levels could be useful markers for detection of microalbuminuria and renal impairment in type 2 diabetic patients with normoalbuminuria.
Keywords: diabetic nephropathy, glomerular filtration rate, cystatin C, sE.cadherin.