IgG4 cholangiopathy: current concept, diagnosis, and pathogenesis.
IgG4 related cholangiopathy, a distinctive type of cholangitis of unknown origin, is characterized by increased serum levels of IgG4, massive infiltration of IgG4-positive plasma cells with storiform fibrosis and/or obliterative phlebitis in the thickened bile duct wall, and good response to steroids. Patients with IgG4-cholangiopathy are frequently associated with autoimmune pancreatitis; IgG4-cholangiopathy is recognized as a biliary manifestation of IgG4-related disease. This condition can be diagnosed by a combination of imaging, serology, histopathology, and steroid responsiveness; however, cholangiographic features are often difficult to differentiate from primary sclerosing cholangitis, pancreatic cancer, or cholangiocarcinoma. The Japanese clinical diagnostic criteria for IgG4-related sclerosing cholangitis established in 2012 are useful in the diagnosis of IgG4-cholangiopathy. Although the precise pathogenic mechanism remains unclear, the development of IgG4-cholangiopathy may involve: susceptible genetic factors, abnormal innate and acquired immunity, decreased naïve regulatory T cells, and specific B cell responses. Further studies on genetic backgrounds, disease specific antigens, and the role of IgG4 are necessary to clarify the pathogenesis.
The Third Department of Internal Medicine, Division of Gastroenterology and Hepatology, Kansai Medical University, Osaka, Japan. Electronic address: okazaki@hirakata.kmu.ac.jp.
Kazuichi
K
Okazaki
The Third Department of Internal Medicine, Division of Gastroenterology and Hepatology, Kansai Medical University, Osaka, Japan.
Kazushige
K
Uchida
The Third Department of Internal Medicine, Division of Gastroenterology and Hepatology, Kansai Medical University, Osaka, Japan.
Masanori
M
Koyabu
The Third Department of Internal Medicine, Division of Gastroenterology and Hepatology, Kansai Medical University, Osaka, Japan.
Hideaki
H
Miyoshi
The Third Department of Internal Medicine, Division of Gastroenterology and Hepatology, Kansai Medical University, Osaka, Japan.
Tsukasa
T
Ikeura
The Third Department of Internal Medicine, Division of Gastroenterology and Hepatology, Kansai Medical University, Osaka, Japan.
Makoto
M
Takaoka
D056704:Adaptive Immunity / Q000502:physiology; D001649:Bile Duct Diseases / Q000175:diagnosis* / Q000209:etiology / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate / Q000502:physiology; D007074:Immunoglobulin G / Q000097:blood*; D008099:Liver / Q000276:immunology / Q000473:pathology; D010950:Plasma Cells / Q000276:immunology / Q000473:pathology
D007074:Immunoglobulin G
Autoimmune pancreatitis; IgG4-cholangiopathy; IgG4-related disease; IgG4-related sclerosing cholangitis