Serum Calprotectin as a Marker for Diagnosis of Spontaneous Bacterial Peritonitis in Cirrhotic Patients with Ascites

Abstract

Spontaneous bacterial peritonitis (SBP) is an ascitic fluid infection without an evident intra-abdominal surgically treatable source. It is one of the most common complications of cirrhosis and its incidence in hospitalized patients with chronic liver disease and ascites varies from 10%-30%. It is a serious disease as the mortality of cirrhotic patients after an episode of spontaneous bacterial peritonitis (SBP) is around 20% to 30%. This study is a case control study aimed to evaluate the role of serum Calprotectin as a non-invasive marker for diagnosis of spontaneous bacterial peritonitis in patients with cirrhotic ascites compared to C-reactive protein. The study was carried out on 75 patients attended Internal Medicine Department in El Sahel Teaching Hospital and Madinet Nasr Medical Insurance Hospital, 25 of them were cirrhotic patients with spontaneous bacterial peritonitis and the other 50 patients were cirrhotic without SBP (25 patients with sterile ascites and 25 without ascites). In this study, we found that SBP was more frequent in males and was not influenced by the age. Regarding the cause of liver cirrhosis in our study, we found that chronic hepatitis C was the cause in 92% of patients whereas chronic hepatitis B was the cause in the remainder with no significant difference in different groups. Patients of SBP in this study were presented mainly with fever (84%), abdominal pain (88%), gastrointestinal bleeding (24%), hepatic encephalopathy (36%), and Jaundice (40%). As regard to the laboratory investigations of the studied patients, we found no significant difference between the groups regarding hemoglobin value, ALT, AST, serum albumin, INR, ascitic fluid glucose and LDH. But we found a high Prevalence of peripheral leukocytosis, thrombocytopenia, elevated ascitic fluid TLC, PMN count, low ascitic protein and high SAAG in SBP patients of the study compared to patients with sterile ascites. We found also that SBP was more common in Child Turcotte Pugh Score class C (92%). In this study, there were higher levels of serum Calprotectin in SBP group than non SBP groups. We found also a significant positive correlation between higher Calprotectin level and raised serum WBC, severity of liver cirrhosis and high ascitic TLC& PMN among SBP patients. We found also that there was a significantly positive correlation between serum Calprotectin and CRP in the studied groups. Using a cut off level of ≥9.0 (mg/dL) for serum CRP in detecting SBP, serum CRP had a highly significant diagnostic performance with AUC 1.000 (P <0.001), sensitivity 100% and specificity 100%. Using a cutoff value ≥46.0 (µg/mL) for serum Calprotectin in detecting SBP in this study revealed that serum Calprotectin had a highly significant diagnostic performance with AUC 0.976 (P <0.001), sensitivity 100% and specificity 92.0%. On comparing the AUC of ROC curve of serum CRP and serum Calprotectin in differentiating between group A (with SBP) and group B (with sterile ascites), it was found that P value was non-significant (P=0.242). Accordingly, serum Calprotectin integrated with serum CRP can be used as a rapid, easy and non-invasive diagnostic marker for SBP.