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). Hist ology with standard stains, culture, and polymerase chain reaction (PCR) am plification using two sets of primers located in the 16S ribosomal DNA (rDN A) were used to detect the presence of bacteria. Amplified products were se quenced to determine the genus and species of the bacteria. A search for ot her genes that were specific for Helicobacter pylori also was carried out b y PCR. RESULTS, PCR performed with the 16S rDNA primers revealed the presence of b acteria from the genus Helicobacter in all of the liver specimens from pati ents with primary liver carcinoma (eight of eight patients) and in one spec imen from a patient without primary liver carcinoma tone of eight patients) . When the nucleo tide sequence of > 80% of the 16S rDNA was determined, th e 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 c losest 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 carci noma, but their eventual role in the carcinogenesis process, although it is plausible, remains to be proven. Based on sequence similarity, it seems th at Helicobacter species that are related closely to H. pylori but are disti nct from it have been found. Cancer 2000;89:1431-9. (C) 2000 American Cance r Society.