title: The Pathology of IgG4-Related Disease in the Bile Duct and Pancreas.
abstract: Immunoglobulin G4-related disease (IgG4-RD) in the pancreatobiliary system manifests as sclerosing cholangitis (SC), hepatic inflammatory pseudotumors, and type 1 autoimmune pancreatitis (AIP). The pathology of IgG4-RD involves an inflammatory process and fibrogenic pathway, the combination of which damages the affected organs. Fibroinflammatory injury is characterized by three microscopic findings: a diffuse lymphoplasmacytic infiltrate rich in IgG4-positive plasma cells, obliterative phlebitis, and storiform fibrosis. Although the diagnosis of IgG4-related pancreatocholangitis is relatively straightforward in surgical specimens, the current clinical requirement is to diagnose patients using biopsy samples, which remains challenging. Histological differential diagnoses include primary SC, follicular cholangitis/pancreatitis, SC with granulocytic epithelial lesions, and type 2 AIP. Although the massive infiltration of IgG4-positive plasma cells is a histological hallmark of IgG4-RD, many other immune cells (e.g., Th2 lymphocytes, regulatory T cells, and M2 macrophages) appear to be strongly involved in orchestral immune reactions.
authors.affiliation: Department of Diagnostic Pathology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yoh
authors.initials: Y
authors.lastname: Zen
mesh_terms: D001327:Autoimmune Diseases / Q000276:immunology / Q000473:pathology; D001649:Bile Duct Diseases / Q000473:pathology*; D001706:Biopsy; D002760:Cholangiopancreatography, Endoscopic Retrograde; D015209:Cholangitis, Sclerosing / Q000276:immunology / Q000473:pathology*; D003937:Diagnosis, Differential; D006104:Granuloma, Plasma Cell / Q000473:pathology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D008107:Liver Diseases / Q000276:immunology / Q000473:pathology*; D008297:Male; D050500:Pancreatitis, Chronic / Q000276:immunology / Q000473:pathology*; D012189:Retrospective Studies
chemical_list: D007074:Immunoglobulin G