Evaluation of Serum Cystatin C as an Early Biomarker of Acute Kidney Injury in Patients with Acute Pancreatitis

Introduction: Acute pancreatitis (AP) is an inflammatory process of pancreas with varying degree of involvement of regional tissues. The aim of this study was to investigate the potential use of serum cystatin C (Cys-C) for the early and accurate diagnosis of acute kidney injury (AKI) in patients of AP. Materials and methods: This was a prospective study conducted in 1 year. Total of 215 cases of AP fulfilling the inclusion criteria were enrolled in this study. Patients suffering from chronic pancreatitis, neoplasm, chronic liver disease, and chronic kidney disease were excluded from the study. Diagnosis of AP was based on the Atlanta classification 2012. All patients were classified into a non-AKI group (n = 152) and an AKI group (n = 38) according to the dynamic changes in serum creatinine levels. Serum Cys-C was measured by particle-enhanced immune nephelometric assay. Results: By univariate logistic regression analysis, body mass index (BMI) (OR = 1.44, 95% CI: 1.23-1.68; p < 0.001), blood urea (OR = 1.15, 95% CI: 1.06-1.23; p < 0.001), Cys-C (OR = 1.04, 95% CI: 1.01-1.07; p < 0.05), serum calcium (OR = 0.59, 95% CI: 0.41-0.86; p < 0.05), and serum lactate dehydrogenase (LDH) (OR = 1.001, 95% CI: 1.0-1.001; p < 0.05) were the significant indicators for AKI in patients with AP. Using multivariate logistic regression analysis, urinary albumin and Cys-C were independent and significant indicators of AKI in patients with AP (OR = 1.026, 95% CI: 1.01-1.07; p < 0.01). Receiver operating characteristic (ROC) curve of serum Cys-C, for AKI in patient with AP could be identified with a sensitivity of 92.06% at specificity of 96.0% [area under the curve (AUC) = 0.96, 95% CI: 0.92-0.98] by baseline serum Cys-C (cutoff value = >32.32 mg/L). Conclusion: Increase of baseline serum Cys-C was associated with AKI in patients with AP.