OBJECTIVETo investigate the levels of lipopolysaccharide binding protein (LBP) in serum and ascites of cirrhotic patients, and determine their diagnostic value for spontaneous bacterial peritonitis (SBP).

METHODSCirrhotic patients were divided into groups according to diagnosis of SBP, ascites without SBP, no ascites. To explore the significance of LBP in clinically suspect SBP cases, the ascites without SBP group was sub-divided into two groups according to the symptoms of abdominal pain or elevated white blood cell (WBC) count, and abdominal pain combined with elevated WBC count. Two control groups were composed of patients with intraperitoneal pus and a group of healthy, non-cirrhotic individuals. The LBP levels in serum and ascites were determined by enzyme-linked immunosorbent assay (ELISA). The ascites routine, ascites culture and albumin assay were carried out in the Second Affiliated Hospital of Chongqing Medical University. Data between the two groups were compared using the t-test or nonparametric test of independent samples, and the areas under the curve were compared using the Z test. Results The levels of LBP in serum and pus were significantly higher in the intraperitoneal pus group than in the cirrhosis group with ascites (P less than 0.01).

RESULTSThe level of serum LBP was significantly higher in the cirrhosis group with SBP than in the cirrhosis group without SBP but with ascites and the cirrhosis group with no ascites (P less than 0.01). There was no significant difference in the level of ascites LBP in the cirrhosis group with SBP and the cirrhosis group without SBP but with ascites (P more than 0.05). In the clinically suspect cases with SBP, the levels of LBP in serum and ascites were significantly higher than those in the cirrhosis group without SBP but with ascites (228.00 mug/ml vs. 80.95 mug/ml and 22.50 mug/ml vs. 11.45 mug/ml, P less than 0.05). Determination of serum LBP had a higher sensitivity than the determination of ascites LBP or ascites WBC.

CONCLUSIONGram-negative bacteria infection in the intra-abdominal cavity causes serum and body fluid levels of LBP to increase significantly. Patients with cirrhosis complicated with SBP have significantly elevated levels of serum LBP. The serum and ascites LBP levels are significantly elevated in SBP patients with suspected clinical diagnosis. Measurements of both the serum LBP and ascites LBP may have diagnostic value for SBP.