Toward reliable and rapid bedside diagnosis of spontaneous bacterial peritonitis in cirrhotic patients

Abstract

Background and aimSpontaneous bacterial peritonitis (SBP) is defined as an ascitic fluid infection without an evident intra-abdominal surgically treatable source. SBP is a common and potentially life-threatening complication in patients with cirrhosis. This prospective study was undertaken to evaluate the usefulness of leukocyte esterase reagent strips and ascitic fluid lactoferrin in the diagnosis of SBP in cirrhotic patients with ascites. Patients and methods A total of 168 patients with cirrhotic ascites were enrolled. Patients with SBP and culture-negative neutrocytic ascites variant were considered positive as SBP. Full history was taken and complete medical examination was performed. All participants were subjected to full laboratory investigations to assess SBP. Paracentesis was performed, and immediately after, fresh ascitic fluid specimen was collected and tested using a dipstick for granulocyte esterase designed for urine analysis. Quantitative measurements of ascitic fluid lactoferrin concentration were determined using a polyclonal antibody-based enzyme-linked immunosorbent assay specific for human lactoferrin. ResultsThe addition of ascitic fluid lactoferrin levels to leukocyte esterase reagent strips yielded statistically significant effects on the diagnostic accuracy compared with each test alone. Thus, the combination of both tests yielded (considering ascitic fluid lactoferrin concentrationZ200 ng/ml and/or dipstick testZ2 +) sensitivity, specificity, positive predictive value, and negative predictive value of 91. 84, 94.96, 88.24, and 96.58%, respectively. ConclusionCombining both ascitic fluid lactoferrin and leukocyte esterase reagent test strips was found to facilitate very rapid identification of patients with SBP. Specifically, these tests can be performed efficiently to speed up the bedside diagnostics of this clinical entity.