IgG4-related Autoimmune Hepatitis with a Suspected Drug-induced Etiology

Abstract

A 69-year-old man was referred to our department with acute hepatitis. He had been newly treated with benidipine hydrochloride for two months. His blood test results were as follows: aspartate aminotransferase, 1,614 IU/L; alanine aminotransferase, 1,091 IU/L and anti-smooth muscle antibody, ×80. Needle liver biopsy specimen showed interface hepatitis with mainly lymphocytic infiltration and bridging fibrosis in the periportal area. Immunohistochemistry revealed lymphocytic infiltration positive for IgG4. We diagnosed him with IgG4-related AIH with an etiology that was suspected of being drug-induced. Oral prednisolone was started and then tapered after achieving biochemical remission. Hepatitis recurred after the cessation of steroids; however, remission was achieved with ursodeoxycholic acid.

Keywords: IgG4; autoimmune hepatitis; drug-induced.

Figure 1.

Computed tomography revealed no mass lesions, stones or biliary duct dilatation.

Figure 2.

a, b: A needle liver biopsy specimen showing interface hepatitis with mainly lymphocytic infiltration and occasional bridging fibrosis in the periportal area, indicating chronic active hepatitis due to AIH (Hematoxylin and Eosin staining, a: ×100, b: ×400). c: Immunohistochemistry showing lymphocytic infiltration lymphocytic infiltration that was positive for IgG4 (140 cells per high-powered field) with an IgG4/IgG-positive cell ratio of 60%, which suggested the IgG4-related type. AIH: autoimmune hepatitis

Figure 3.

Clinical course. AST: aspartate aminotransferase, ALT: alanine aminotransferase, γ-GTP: γ-glutamyl transpeptidase, PSL: prednisolone, UDCA: ursodeoxycholic acid