Serological analysis of Helicobacter hepaticus infection in patients with biliary and pancreatic diseases.
Infection with Helicobacter hepaticus has been associated with development of hepatocellular carcinoma and gallstones in animal models. In humans, however, the association of H. hepaticus infection with biliary and pancreatic diseases has not been elucidated. The aim of this study was to serologically examine the prevalence of H. hepaticus infection in patients with biliary and pancreatic diseases. Serum samples obtained from 55 patients with cholelithiasis, 18 with bile duct or gallbladder cancer and 19 with pancreatic cancer were studied. Sera were obtained from 34 control subjects who underwent endoscopy and were diagnosed as not having peptic ulcers or cancers. Seropositivity of H. hepaticus was examined by western blot analysis using a H. hepaticus-specific antigen. To validate the specificity, positive sera were also tested after absorption with H. hepaticus whole-cell sonicate. Serum samples were also tested for the presence of anti-Helicobacter pylori antibody. Prevalence of antibody to H. hepaticus-specific antigen in patients with bile tract cancer was 38.8% and was significantly higher than in control subjects (13.1%, P < 0.05). Prevalence of antibody to H. hepaticus-specific antigen was 18.2% and 10.5% in patients with cholelithiasis and pancreatic cancer, respectively. Seropositivity for H. pylori was similar in all groups. Detection of the H. hepaticus-specific band was significantly decreased after the sera were absorbed with H. hepaticus whole-cell sonicate. Infection with H. hepaticus might be associated with bile duct cancer. Results obtained from absorbed sera suggested high specificity of the western blot analysis.