Involvement of the biliary system in autoimmune pancreatitis: a follow-up study

Abstract 

: The aim of this study was to define the bile duct changes associated with autoimmune pancreatitis. : Eight patients with autoimmune pancreatitis were followed for a mean of 4 years. The clinical features of these patients, including extrapancreatic bile duct changes, were examined by using biochemical parameters and several imaging modalities. Pathologic features of the pancreas and liver were examined by using the biopsy specimens of 7 patients. : Diffuse or focal narrowing of the main pancreatic duct was observed in all patients. Histologic examination of the pancreas showed lymphoplasmacyte infiltration with severe fibrosis and acinar cell depletion. In 6 patients extrapancreatic bile duct changes such as stricture of the bile duct at hilus or intrahepatic area were observed. In 2 patients abnormalities in the bile duct and pancreas were detected simultaneously at diagnosis, and changes in the bile duct were observed later in 4 patients. Lymphoplasmacyte infiltration and fibrosis were observed in the portal area of all 7 liver biopsy samples. Five of the patients with bile duct changes received steroid therapy, and the pathological changes improved. : Extrapancreatic bile duct changes are frequently associated with autoimmune pancreatitis. Similar pathogenic mechanism might produce the biliary tract and pancreatic abnormalities in autoimmune pancreatitis resulting in a similar histopathology in the liver and pancreas and response to steroid therapy.

Keywords:  ACA-II, anticarbonic anhydrase-II, ALP, alkaline phosphatase, AMA, antimitochondrial antibody, ANA, antinuclear antibody, CA19-9, carbohydrate antigen 19-9, CEA, carcinoembryonic antigen, CRP, C-reactive protein, CT, computed tomography, D.Bil, direct bilirubin, EBD, endoscopic biliary drainage, ERCP, endoscopic retrograde cholangiopancreatography, FBS, fasting blood sugar, GAD, glutamic acid decarboxylase, γ-GTP, γ-glutamyl transpeptidase, HbA1c, hemoglobin A1c, IDUS, intraductal ultrasonography, MPO-ANCA, myeloperoxidase-antineutrophil cytoplasmic antibody, MRI, magnetic resonance imaging, PBC, primary biliary cirrhosis, PFD, pancreatic function diagnostic test, PNPD, pancreatitis with narrowing pancreatic duct, PSC, primary sclerosing cholangitis, PTBD, percutaneous transhepatic biliary drainage, PTC, percutaneous transhepatic cholangiography, RF, rheumatoid factor, RNP, ribonucleoprotein, SSA, sicca syndrome A, SSB, sicca syndrome B, T.Bil, total bilirubin, US, ultrasonography