Serum Calprotectin as a Non-invasive Diagnostic Marker for Spontaneous Bacterial Peritonitis in Egyptian Cirrhotic Patients

Abstract

BACKGROUND and AIM: Delayed diagnosis of spontaneous bacterial peritonitis (SBP) is associated with high mortality in cirrhotic patients. Therefore, there is a need for a rapid non-invasive diagnostic tool. This work aimed at evaluating the role of serum calprotectin as a non-invasive diagnostic marker for SBP in comparison to C-reactive protein (CRP). METHODS: 75 cirrhotic patients were included and divided into three groups. Group A: 25 patients with cirrhotic ascites and SBP diagnosed by presence of PMNL ≥ 250/mm 3 in ascitic fluid with or without positive ascitic fluid culture. Group B: 25 patients with cirrhotic ascites without SBP. Group C: 25 cirrhotic patients with no clinical or ultrasound evidence of ascites as a control group. All were subjected to complete clinical evaluation, routine laboratory investigations, serum calprotectin, CRP levels and diagnostic abdominal paracentesis (only for group A and B). RESULTS: Group A showed significantly higher levels of ascitic fluid total leukocytic count, polymorphonuclear leukocytes and total protein (P<0.001) in comparison to Group B. Group A had significantly higher serum calprotectin and CRP levels than other groups. There were significant positive correlations between serum calprotectin and serum WBC, CRP and ascitic fluid TLC, PMNL and total protein among group A. Serum calprotectin and CRP had the most significant diagnostic performance in detection of SBP (AUC=0.976 and 1.000 respectively, P<0.001). A cut-off level of serum calprotectin≥46.0 μg/mL showed a sensitivity of 100%, specificity 92% and diagnostic accuracy 96%; while that of CRP≥9.0 mg/dL showed a sensitivity of 100%, specificity 100% and diagnostic accuracy 100%. CONCLUSION: Serum calprotectin in combination with CRP may be useful for non-invasive diagnosis of SBP.