Serum homocysteine as an early diagnostic marker of spontaneous bacterial peritonitis in patients with hepatic cirrhosis

Abstract

Background: Spontaneous bacterial peritonitis (SBP) is a term used to describe acute infection of ascites, an abnormal accumulation of fluid in the abdomen, without a distinct or identifiable source of infection.
Objective: This study aimed to assess serum homocysteine as a novel reliable early diagnostic marker for spontaneous bacterial peritonitis in patients with hepatic cirrhosis. As the diagnosis of SBP depends primarily on a polymorphonuclear leukocyte cell (PMN) count ≥ 250 mm3, however this method is invasive and sometimes not diagnostic. Patients and methods: This study was conducted on 50 cirrhotic patients with ascites. Patients were divided into 2 groups: Group (A) included 30 cirrhotic patients with SBP on the basis of PMN count in the ascitic fluid ≥ 250 cells/μL with or without positive ascitic fluid culture. Group (B) included 20 cirrhotic patients with ascites but without SBP (control group). Results: There was a significant difference between the two studied groups regarding C-reactive protein (CRP) (P=0.001) and erythrocyte sedimentation rate (ESR) (P=0.008). There was also significant difference between the two studied groups regarding ascitic fluid analysis parameters; as ascitic glucose and albumin were significantly lower in SBP group (P=0.002 & P=0.027, respectively) while ascitic lactate dehydrogenase (LDH) and PMN count were significantly higher in SBP group (P < 0.001, for both). Serum homocysteine was significantly higher in SBP group compared to non-SBP group (18.43 ± 6.95 vs. 12.13 ± 5.54 μmol/l; P=0.001). Serum homocysteine was significant at a cutoff level of 17.65 μmol/l with a sensitivity of 88.6% and 95.2% specificity for diagnosing SBP with an area under the curve (AUC) = 0.928.
Conclusion: Serum homocysteine could serve as a convenient novel and reliable noninvasive early diagnostic marker for SBP in cirrhotic patients with ascites.