Ascitic Calprotectin is a Novel and Accurate Marker for Spontaneous Bacterial Peritonitis

Abstract

Background: Spontaneous bacterial peritonitis (SBP) is a known complication of advanced cirrhosis and presents a high mortality rate. A polymorphonuclear (PMN) cell count >250/μl in the ascitic fluid is the current gold standard for diagnosing SBP. Aim: We evaluated the accuracy of a point-of-care test (POCT) for ascitic calprotectin in diagnosing patients with SBP. Methods: Eighty-eight patients admitted with decompensation of liver cirrhosis were studied including 41 patients (46.6%) with SBP. Ascitic calprotectin was measured using a quantitative POCT developed by Bühlmann®. Results: Calprotectin levels correlated with PMN cell count and other inflammatory markers and were significantly higher in patients with SBP. An optimal cutoff of calprotectin above 1.57 μg/ml presented high sensitivity (87.8%), specificity (97.9%), and positive (97.3%) and negative (90.2%) predictive values for diagnosing SBP. Using calprotectin selectively in patients with a serum albumin-ascites gradient above 11 g/l further increased the sensitivity and negative predictive values of the test. Conclusion: Ascitic calprotectin appears to be a reliable method for diagnosing SBP in patients with liver cirrhosis. It may present an alternative to other conventional diagnostic methods.