Resumo

INTRODUCTION: several studies have shown the presence of Helicobacter DNA in the liver specimens of patients with hepatobiliary diseases mainly cirrhosis, cholangiocarcinoma and hepatocellular carcinoma (HCC). Considering that H. pylori is classified as a type I carcinogen and hepatocelular carcinoma represents one of the most common human cancers in the world, the aim of this study was to investigate the presence of H. pylori DNA in the FFPE liver from Brazilian patients with and without HCC. SUBJECTS AND METHODS: for this purpose, paraffin sections of 38 liver biopsies from patients with HCC (Group A) and 17 control subjects with no evidence of preexisting liver disease (Group B) were used. Genomic DNA was extracted from these paraffin sections using phenol/chloroform method. After that, polymerase chain reaction (PCR) analysis was carried out using H. pylori specific 16S rRNA primers and PCR products of positive samples were further identified by DNA sequencing. DISCUSSION: results showed that 14 of the 38 samples were positive in Group A (36,8%) and 3 of the 17 patients (17,6%) amplified the 16S rRNA gene in Group B. The nucleotide sequence of the 16SrRNA amplicons demonstrated 98% similarity to H. pylori. Considering the H. pylori positive patients in group GA, in relation to viral infection, 9 of the 14 (64%) subjetcs were infected by hepatitis C virus (HCV), 2 (14%) were infected by hepatitis B virus (HBV); 1 (7%) presented coinfection with HCV and HBV and 2 (15%) patients had HCC without viral infection. CONCLUSIONS: these data confirm the identification of H. pylori in FFPE liver tissue of Brazilian patients with and without hepatocelular carcinoma; furthermore, in the first group, patients were most frequently infected by HCV. Further studies will be performed in these samples to detect other H. pylori molecular markers such as cagA, vacA and ureA genes.