Immunoglobulin G4-related autoimmune hepatitis simultaneously concomitant with autoimmune pancreatitis: a case report.

Thus far, there have been limited case reports on immunoglobulin G4-related autoimmune hepatitis (IgG4-AIH), and its clinical features have not been elucidated. We herein report a rare case of IgG4-AIH simultaneously concomitant with autoimmune pancreatitis (AIP). A 73-year-old female was admitted to our hospital for further investigation of elevated levels of liver transaminase and pancreatic enzymes. Her serological tests showed a high antinuclear antibody titer, and elevated IgG and IgG4 levels. Liver biopsy revealed interface hepatitis and bridging necrosis with IgG4-positive lymphoplasmacytic infiltration in the portal area. Moreover, contrast-enhanced computed tomography (CECT) showed pancreatic tail enlargement, and magnetic resonance cholangiopancreatography showed skipped narrowing of the main pancreatic duct in the pancreatic tail. Endoscopic ultrasonography-fine needle aspiration specimens showed no malignant cells. Based on these results, we diagnosed her with IgG4-AIH simultaneously concomitant with probable type 1 AIP. She was started on prednisolone (PSL) at 35 mg/d, and her symptoms and liver transaminase levels improved. One month after starting treatment, CECT showed improvement of pancreatic tail enlargement. She is maintained on 5 mg PSL/d and has been in remission for two years.