Abstract
Objective: Bacterial translocation (BT) or bacterial DNA (bactDNA) translocation is a critical pathogenesis mechanism of spontaneous bacterial peritonitis. Studies of BT or bactDNA translocation are limited in humans. Neutrophil gelatinase associated lipocalin (NGAL) can efficiently distinguish bacterial and nonbacterial ascites in ascitic patients. Hepcidin is a useful marker of bacterial infection in the late-onset sepsis. However, the relationship between NGAL, hepcidin and BT was still unclear. In present study, the levels of NGAL, hepcidin and their relationship with BT or bactDNA translocation were investigated. Material and methods: Weekly doses of carbon tetrachloride (CCl4) were given to induce liver cirrhosis in Sprague-Dawley rats. Trypticase (blood) soy agars were used to culture bacteria. BactDNA was sequenced by ABIPRISM 310 automated sequencer. The levels of NGAL and hepcidin were assessed by ELISA. Receiver operating characteristic (ROC) curve was used to determine the cut-off values and compare the diagnostic performance of NGAL and hepcidin. Results: 56 cirrhotic and 10 normal rats were included in this study. The levels of both two biomarkers were significantly higher in BT or bactDNA translocation group compared to non-translocation group. The area under ROC curve for the diagnosis of BT was 0.910 for serum NGAL, 0.858 for serum hepcidin and 0.940 for their combination, whereas that for the diagnosis of bactDNA translocation was 0.906 for NGAL, 0.779 for hepcidin and 0.950 for their combination, respectively. The combination of NGAL and hepcidin improved the ability to detect BT or bactDNA presence in MLNs and ascites. Conclusion: BT and the presence of bactDNA in MLNs were observed in a rat cirrhotic model. Serum NGAL and hepcidin can serve as sensitive and specific tests for diagnosis of BT or bactDNA translocation. NGAL in combination with hepcidin can improve the accuracy of diagnosis.
Keywords: Bacterial translocation, bacterial DNA translocation, liver cirrhosis, neutrophil gelatinase associated lipocalin, hepcidin, ROC curve
