Association of Helicobacter species with hepatitis C cirrhosis with or without hepatocellular carcinoma.

BACKGROUND AND AIMS: Recent studies have suggested that bacterial coinfection with Helicobacter species in patients already infected with hepatitis C virus (HCV) could be involved in the development of cirrhosis and hepatocellular carcinoma (HCC). A retrospective cross sectional study was performed in order to explore the association between Helicobacter species and HCV associated liver diseases. METHODS: The presence of Helicobacter species was tested by polymerase chain reaction on liver samples from four groups of patients. RESULTS: Helicobacter 16S rDNA was found in only 4.2% of liver samples from control patients (n=24) and in 3.5% of liver samples from patients with non-cirrhotic chronic hepatitis C (n=29) while it was found in 68.0% of liver samples from patients with HCV positive cirrhosis without HCC (n=25) as well as in 61.3% of cirrhotic liver samples from patients with HCV positive cirrhosis and HCC (n=31). In addition, when the HCC tumour tissue was tested (n=21), 90.5% of samples were positive. DNA from Helicobacter pylori- and Helicobacter pullorum-like organisms was found. CONCLUSIONS: There is an association between the presence of Helicobacter species DNA in the liver and hepatitis C cirrhosis, with or without HCC. Indeed, the presence of these bacteria could be the result of structural changes in the liver. Alternatively, Helicobacter species could be a co-risk factor in HCV chronic liver diseases. This result warrants prospective studies to determine the possible causal role of these bacteria in the progression of chronic hepatitis C.

Detection of Helicobacter species in the liver of patients with and without primary liver carcinoma.

BACKGROUND: Several studies have shown the presence of Helicobacter species in the human biliary tract and in the intestinal tract of animals. In this study, the presence of Helicobacter species in liver samples from patients with primary hepatic carcinomas was evaluated. METHODS: Sixteen liver specimens were studied (8 from patients with primary liver carcinoma and 8 from patients without primary liver carcinoma). Histology with standard stains, culture, and polymerase chain reaction (PCR) amplification using two sets of primers located in the 16S ribosomal DNA (rDNA) were used to detect the presence of bacteria. Amplified products were sequenced to determine the genus and species of the bacteria. A search for other genes that were specific for Helicobacter pylori also was carried out by PCR. RESULTS: PCR performed with the 16S rDNA primers revealed the presence of bacteria from the genus Helicobacter in all of the liver specimens from patients with primary liver carcinoma (eight of eight patients) and in one specimen from a patient without primary liver carcinoma (one of eight patients). When the nucleotide sequence of > 80% of the 16S rDNA was determined, the closest similarity was with the 16S rDNA from H. pylori in eight patients. In 1 patient sample from which only 398 nucleotides were sequenced, the closest match was Helicobacter felis. CONCLUSIONS: The results presented in this study indicate that Helicobacter species can be present in the liver of patients with primary hepatic carcinoma, but their eventual role in the carcinogenesis process, although it is plausible, remains to be proven. Based on sequence similarity, it seems that Helicobacter species that are related closely to H. pylori but are distinct from it have been found.