Procalcitonin is a useful biomarker to predict severe acute cholangitis: a single-center prospective study

Procalcitonin is being increasingly used to diagnose and grade acute systemic bacterial infection at an early stage of disease onset. The aim of this prospective study was to evaluate the usefulness of procalcitonin for severity grading of acute cholangitis on patient admission. Patients with acute cholangitis were prospectively enrolled. The severity of acute cholangitis was graded on the basis of the 2013 Tokyo guidelines (Japanese Society of Hepato-Biliary-Pancreatic Surgery, 2013). We compared the ability of procalcitonin level on admission to predict moderate/severe (vs mild) or severe (vs mild/moderate) acute cholangitis with the abilities of white blood cell (WBC) count and C-reactive protein (CRP) level. Two hundred thirteen patients were analyzed, and the severity of acute cholangitis was graded as mild, moderate, and severe in 108, 76, and 29 patients respectively. Procalcitonin level, WBC count, and CRP level all increased significantly according to the severity. In the receiver operating characteristic analyses, the area under the curve for procalcitonin for severe acute cholangitis was 0.90 [95% confidence interval (CI) 0.85-0.96] and was significantly greater than that for WBC (0.62; 95% CI 0.48-0.76) and that for CRP (0.70; 95% CI 0.60-0.80). The optimal cutoff value for procalcitonin for prediction of severe acute cholangitis was 2.2 ng/mL (sensitivity 0.97; specificity 0.73; accuracy 0.77). The areas under the curve for procalcitonin, WBC, and CRP for moderate/severe acute cholangitis were not significantly different. Procalcitonin predicted severe acute cholangitis better than conventional biomarkers. Severe cases for which urgent biliary drainage is indicated might be identified on admission on the basis of the cutoff values for procalcitonin suggested in this study.