The Clinical Significance of Detecting Bacterial DNA by in situ Hybridization Method in Patients With Decompensated Liver Cirrhosis

Abstract

Introduction: Patients with decompensated cirrhosis often suffer from various complications such as spontaneous bacterial peritonitis (SBP). However, it is difficult to diagnose SBP or bacteremia because bacteria in ascites or blood cannot be detected accurately by conventional culture method. It has been showed that the method using in situ hybridization (ISH) for detecting the gene of bacteria phagocytized by neutrophil in ascites is possibly useful to diagnose SBP within one day (Enomoto et al. J Hepatology 2012). It is thought that SBP is developed following bacteremia after bacterial translocation from the intestinal tract. Therefore we used the ISH method for blood samples taken from patients with decompensated liver cirrhosis and evaluated the significance of bacterial detection. Methods: Samples of peripheral blood and ascites were collected from 35 patients with ascites caused by liver cirrhosis. Blood samples were examined for bacteria using both conventional blood culture and ISH method. Samples of ascites were also evaluated by conventional culture simultaneously. The ISH method we used was the kit from Fuso Pharmaceuticals (Tokyo, Japan). Results: Eight of 35 patients were diagnosed with SBP. Six of the 8 patients showed positive results using the ISH method while bacteria were detected inonly one case byblood culture and one case by ascites culture. In 27 patients without SBP, 15 patients showed positive results using the ISH method while bacteria were detected in 4 cases by blood culture. The differences between 21 positive and 14 negative results by the ISH method were significant in presence of fever (16 / 5, p < 0.05) and decreased serum albumin levels (2.3 / 2.7, p < 0.05). However, there was no significant difference between administration of antibiotics, C-reaction protein level, and the presence of hepatocellular carcinoma. Notably, no patient who had a positive blood culture had a negative ISH result. Conclusion: The ISH method resulted in a higher positive rate of bacterial detection than culture in patients with decompensated cirrhosis. These results might implicate that “bacterial translocation,” which cannot be proved by conventional culture methods, really occurs. Therefore, it would be better for these patients with positive ISH results to be treated immediately. In patients with decompensated cirrhosis, the ISH method can be helpful for rapid diagnosis and early management of bacteremia and SBP.