BACKGROUND: Currently adopted diagnostic methods for duodenal-biliary and pancreaticobiliary refluxes carry many flaws, so the incidence of the two refluxes demands further larger sample size studies. This study aimed to evaluate Western blotting for the diagnosis of refluxes in biliary diseases.
METHODS: An oral radionuclide 99mTc-DTPA test (radionuclide, RN) was conducted for the observation of duodenal-biliary reflux prior to measuring bile radioactivity and Western blotting for detecting bile enterokinase (EK). Pancreaticobiliary reflux was assessed by biochemical and Western blotting tests for biliary amylase activity and trypsin-1, respectively. In accordance with bile sample origin, our samples were classified into ductal bile and gall bile groups; based on each individual biliary disease, we further classified the ductal bile group into five sub-groups, and the gall bile group into four sub-groups. Western blotting was conducted to assess the two refluxes in biliary diseases.
RESULTS: Consistencies were noted between EK and RN tests when diagnosing duodenal-biliary reflux (P<0.001). The amylase and trypsin-1 tests also showed consistency in diagnosing pancreaticobiliary reflux (P<0.001). Amylase and lipase levels within gall and ductal bile were strongly correlated (P<0.05). In the common bile duct pigment stone group, the EK and trypsin-1 positive rates were found to be insignificant (P>0.05); in the common bile duct cyst group, the EK positive rate was significantly lower than the trypsin-1 positive rate (P<0.05).
CONCLUSIONS: Western blotting can accurately reflect duodenal-biliary and pancreaticobiliary refluxes. EK has greater sensitivity than RN for duodenal-biliary reflux. The majority of biliary amylase and lipase comes from the pancreas in all biliary diseases; pancreaticobiliary reflux is the predominant source in the common bile duct cyst group and duodenal-biliary reflux is responsible for the ductal pigment stone group.