Abstract
We herein report a case of IgG4-related autoimmune hepatitis (AIH) in a patient with a history of type 1 autoimmune pancreatitis. A 56-year-old man presented with fatigue and jaundice at our hospital. A blood biochemistry analysis revealed significant liver dysfunction, positive results for antinuclear antibodies, and high serum IgG4 levels. A histopathological examination revealed interface hepatitis marked by IgG4-positive plasma cell infiltration in the portal area, leading to liver cell depletion and necrosis. Based on the diagnosis of IgG4-related AIH, prednisolone treatment was initiated, which led to the rapid resolution of liver dysfunction and jaundice. An accurate diagnosis of IgG4-related AIH is crucial to prevent secondary manifestations.