Identification of Helicobacter species by 16S rDNA PCR and sequence analysis in human liver samples from patients with various etiologies of benign liver diseases

Abstract

Several reports indicated an increased prevalence of the Helicobacter species in hepatocellular cancer tissue and in liver samples infected with hepatitis viruses. The frequency of Helicobacter spp. in benign liver diseases was, however, not thoroughly investigated. Seventy-five consecutive patients with suspected liver disease were enrolled. The indications were hepatitis B virus (n=30), C virus (n=8), B and C dual infection (n=1), nonalcoholic steatohepatitis (n=27), autoimmune hepatitis (n=3), primary biliary cirrhosis (n=1) and idiopathic elevation of liver enzymes (n=5). PCR detection of 16S recombinant RNA gene of Helicobacter spp. was performed on liver samples. PCR products of positive samples were further identified by DNA sequencing. The patients also had upper gastrointestinal endoscopy and gastric biopsy for the detection of H. pylori using histopathology and PCR. Helicobacter spp. DNA was detected in two out of 75 liver biopsy samples (2.6%), which were typed as H. pylori by DNA sequencing. One of these patients had chronic hepatitis C infection (man, 51 years old) and the other had nonalcoholic steatohepatitis (woman, 44 years old). Fifty-two out of 75 of the patients (69.3%) had H. pylori infection in their stomachs. We have found that H. pylori infection is much less prevalent in benign liver diseases. The presence of H. pylori in nonalcoholic steatohepatitis (NASH) patients is a novel finding and this finding should be confirmed in a larger series.