Association and prognostic value of serum Cystatin C, IL-18 and Uric acid in urological patients with acute kidney injury

Purpose: To assess the role of serum Cystatin C, IL-18 and Uric acid in acute kidney injury (AM) in urological patients, along with their prognostic significance. Materials and methods: Prospective observational study included 61 cases, admitted in urology ward with baseline serum creatinine <= 1.5 mg/dL. All patients had at least one or more predisposing factors for AKI. Daily urine output and creatinine level were checked. Serum levels of biomarkers were measured at baseline and postoperatively after 24 h. Development of AM and its outcome were analysed. Results: Thirty nine patients (63.9%) developed AM in the study. Patients with AKI were found to have a greater percentage rise of Cystatin C (118.7% v/s 81.8%, p = 0.005), IL-18 (59.0% v/s 25.5%, p = 0.004) and Uric acid (34.3% v/s 19.2%, p = 0.008) after 24 h. Absolute Uric acid level at day 1 was also significantly associated with AKI (5.18 0.91 v/s 4.45 0.86, p = 0.003). Risk stratification of AKI was poor for all biomarkers. Area under curve for Cystatin C, IL-18 and Uric acid was 0.715, 0.696 and 0.734 respectively. Renal function after 3 months, had a positive correlation with baseline creatinine and baseline Cystatin C levels (r = 0.56 & 0.39). Conclusions: Postoperative serum Cystatin C, IL-18 and Uric acid after 24 h were significantly associated with AM. Baseline Cystatin C had moderate capability to predict short term renal function.