The Ratio of Calprotectin to Total Protein as A Diagnostic Marker for Spontaneous Bacterial Peritonitis in Patients with Liver Cirrhosis and Ascites

Background: Spontaneous bacterial peritonitis (SBP) is a potentially fatal condition, characterized by infection of ascitic fluid in absence of any intra-abdominal surgically treatable source of infection. Diagnosis of SBP is based on a differential ascites leucocytic count. Aim of the Work: to assess the role of ascitic fluid calprotectin in diagnosis of SBP. Patients and Methods: A cross-sectional study was conducted on 60 patients with decompensated liver disease were selected. They were divided into: 1) Non-SBP Group: included 30 patients with cirrhotic ascites without clinical or laboratory evidence of spontaneous bacterial peritonitis. 2) SBP Group: included 30 patients with cirrhotic ascites and spontaneous bacterial peritonitis. Results:. Ascitic fluid calprotectin level and the ratio of calprotectin to total protein was statistically significantly higher in the SBP group than the non-SBP group. There was a significant decrease in total protein and albumin in ascitic fluid in SBP group compared to the non-SBP group.A significant positive correlation was detected between ascitic fluid calprotectin and ascitic fluid TLC and PNLs among SBP group, A significant positive correlation between the ratio of calprotectin to total protein and ascitic fluid TLC and PNLs among SBP group. Ascitic fluid calprotectin at cut-off value 96 ng/ml, had a sensitivity of 86.67 % and a specificity of 76.67 % in the diagnosis of SBP with positive predictive value 85.2 % and negative predictive value 78.8%. - The ratio of calprotectin to total protein at cut-off value 9.6, had a sensitivity of 96.67 % and a specificity of 90 % in the diagnosis of SBP with positive predictive value 96.4 % and negative predictive value 90.6%. Conclusion: The ratio of calprotectin to total protein had high sensitivity and specificity in the diagnosis of SBP and better than calprotectin alone. The ratio of calprotectin to total protein could be a useful diagnostic test for SBP.