Identification of Helicobacter pylori and other Helicobacter species by PCR, hybridization, and partial DNA sequencing in human liver samples from patients with primary sclerosing cholangitis or primary biliary cirrhosis

Helicobacter pylori was identified in human liver tissue by PCR, hybridizat ion, and partial DNA sequencing. Liver biopsies were obtained from patients with primary sclerosing cholangitis (n = 12), primary biliary cirrhosis (n = 12), and noncholestatic liver cirrhosis (n = 13) and las controls) norma l livers (n = 10). PCR analyses were carried out using primers for the Heli cobacter genus, Helicobacter pylori (the gene encoding a species-specific 2 6-kDa protein and the 16S rRNA), Helicobacter bills, Helicobacter pullorum, and Helicobacter hepaticus. Samples from patients with primary biliary cir rhosis and primary sclerosing cholangitis (11 and 9 samples, respectively) were positive by PCR with Helicobacter genus-specific primers. Of these 20 samples, 8 were positive with the 16S rRNA primer and 9 were positive with the 26-kDa protein primer of H. pylori. These nine latter samples were also positive by Southern blot hybridization for the amplified 26-kDa fragment, and four of those were verified to be H. pylori by partial 16S rDNA sequen cing. None of the samples reacted with primers for H. bills, H. pullorum, o r H. hepaticus. None of the normal livers had positive results in the Helic obacter genus PCR assay, and only one patient in the noncholestatic liver c irrhosis group, a young boy who at reexamination showed histological featur es suggesting primary sclerosing cholangitis, had a positive result in the same assay. Helicobacter positivity was thus significantly more common in p atients with cholestatic diseases (20 of 24) than in patients with nonchole static diseases and normal controls (1 of 23) (P = <0.00001). Patients posi tive for Helicobacter genus had significantly higher values of alkaline pho sphatases and prothrombin complex than Helicobacter-negative patients (P = 0.0001 and P = 0.0003, respectively). Among primary sclerosing cholangitis patients, Helicobacter genus PCR positivity was weakly associated with ulce rative colitis (P = 0.05). Significant differences related to blood group o r HLA status were not found.