Hanafusa Ryusuke, Tajiri Kazuto, Muraishi Nozomu, Hirabayashi Kenichi, Tsuneyama Koichi, Yasuda Ichiro
Third Department of Internal Medicine, Toyama University Hospital, 2630 Sugitani, Toyama, 930-0194, Japan.
Department of Diagnostic Pathology, Toyama University Hospital, Toyama, Japan.
Clin J Gastroenterol. 2025 Jun 17. doi: 10.1007/s12328-025-02161-8.
Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease caused by an autoimmune response to hepatocytes, predominantly affecting middle-aged and older women. A subset of AIH cases has been associated with immunoglobulin G4-related disease (IgG4-RD), referred to as IgG4-AIH. This rare condition is characterized by IgG4-positive plasma cell infiltration in the portal area and elevated serum IgG4 levels. Despite its rarity, IgG4-AIH has been proposed as a distinct disease entity. Here, we report a case of IgG4-AIH associated with multiple inflammatory pseudotumors (IPTs) and decreased organic anion transporting peptide (OATP) 1B3 expression. Hepatic IPTs are typically composed of lymphoplasmacytic and fibroblastic accumulations. In the present case, OATP1B3 expression was relatively decreased without such accumulation according to IgG4-related inflammation, suggesting that IgG4-related inflammation may regulate OATP1B3 expression.
自身免疫性肝炎（AIH）是一种由针对肝细胞的自身免疫反应引起的慢性炎症性肝病，主要影响中年及老年女性。一部分AIH病例与免疫球蛋白G4相关疾病（IgG4-RD）有关，称为IgG4-AIH。这种罕见疾病的特征是门静脉区域IgG4阳性浆细胞浸润和血清IgG4水平升高。尽管IgG4-AIH罕见，但已被提议作为一种独特的疾病实体。在此，我们报告一例与多个炎性假瘤（IPT）相关且有机阴离子转运多肽（OATP）1B3表达降低的IgG4-AIH病例。肝脏IPT通常由淋巴细胞和浆细胞以及成纤维细胞聚集组成。在本病例中，根据IgG4相关炎症，OATP1B3表达相对降低且无此类聚集，提示IgG4相关炎症可能调节OATP1B3表达。
