Early detection of acute kidney injury by serum cystatin C in critically ill children

Background We prospectively evaluated whether serum cystatin C (CysC) detected acute kidney injury (AKI) earlier than basal serum creatinine (Cr). Methods In 107 pediatric patients at high risk of developing AKI, serum Cr and serum CysC were measured upon admission. Baseline estimated creatinine clearance ( eCCl ) was calculated using a CysC-based glomerular filtration rate (GFR) equation from a serum Cr measured at the pediatric intensive care unit (PICU) entrance. Results The median age was 10 months (interquartile range, 3–36 months). Serum Cr, serum CysC, and eCCl (mean ± standard deviation [range]) were 0.5 ± 0.18 mg/dl (0.2–1.1 mg/dl), 0.53 ± 0.78 (0.01–3.7 mg/l), and 72.55 ± 28.72 (20.6–176.2) ml/min per 1.73 m 2 , respectively. The serum CysC level in patients with AKI was significantly higher than children with normal renal function ( p