title: IgG4-associated cholangitis: a comparative histological and immunophenotypic study with primary sclerosing cholangitis on liver biopsy material.
abstract: IgG4-associated cholangitis is a steroid-responsive hepatobiliary inflammatory condition associated with autoimmune pancreatitis that clinically and radiologically mimics primary sclerosing cholangitis. In this study, we conducted a morphological and immunohistochemical analysis of liver material obtained from individuals with IgG4-associated cholangitis, and compared these with well-characterized cases of primary sclerosing cholangitis. The study group consisted of 10 patients (9 biopsy and 1 hepatectomy case) with IgG4-associated cholangitis and 17 patients with primary sclerosing cholangitis (16 needle biopsy and 1 hepatectomy case). All patients with IgG4-associated cholangitis had pancreatic involvement as well, and six pancreatectomy samples revealed characteristic histopathological features of autoimmune pancreatitis. Primary sclerosing cholangitis cases were defined by the presence of a characteristic ERCP appearance. Clinical, pathological, radiological, and follow-up data were recorded for all cases. Portal and periportal inflammation was graded according to Ishak's guidelines. Immunohistochemical stains for IgG and IgG4 were performed. The cohort of patients with IgG4-associated cholangitis (mean age: 63 years) was older than individuals with primary sclerosing cholangitis (mean age: 44 years). Seven of these cases showed intrahepatic biliary strictures. IgG4-associated cholangitis liver samples showed higher portal (P=0.06) and lobular (P=0.009) inflammatory scores. Microscopic portal-based fibro-inflammatory nodules that were composed of fibroblasts, plasma cells, lymphocytes, and eosinophils were exclusively observed in five of the IgG4-associated cholangitis cases (50%). More than 10 IgG4-positive plasma cells per HPF (high power field) were observed in 6 of the IgG4-associated cholangitis cases (mean: 60, range: 0-140 per HPF), whereas all primary sclerosing cholangitis cases showed significantly lesser numbers (mean: 0.08, range: 0-1 per HPF). On a liver biopsy, the histological features of IgG4-associated cholangitis may be distinctive, and in conjunction with IgG4 immunohistochemical stain, may help distinguish this disease from primary sclerosing cholangitis.
authors.affiliation: The James Homer Wright Pathology Laboratories, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street,Boston, MA 02114, USA. VDESHPANDE@PARTNERS.ORG
authors.forename: Vikram
authors.initials: V
authors.lastname: Deshpande
authors.forename: Nisha I
authors.initials: NI
authors.lastname: Sainani
authors.forename: Raymond T
authors.initials: RT
authors.lastname: Chung
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Pratt
authors.forename: Gilles
authors.initials: G
authors.lastname: Mentha
authors.forename: Laura
authors.initials: L
authors.lastname: Rubbia-Brandt
authors.forename: Gregory Y
authors.initials: GY
authors.lastname: Lauwers
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001327:Autoimmune Diseases / Q000150:complications* / Q000276:immunology / Q000473:pathology; D001707:Biopsy, Needle; D049448:Cholangiopancreatography, Magnetic Resonance; D002761:Cholangitis / Q000276:immunology* / Q000473:pathology / Q000628:therapy; D015209:Cholangitis, Sclerosing / Q000276:immunology* / Q000473:pathology / Q000628:therapy; D003937:Diagnosis, Differential; D005260:Female; D006498:Hepatectomy; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007150:Immunohistochemistry; D016130:Immunophenotyping; D008099:Liver / Q000276:immunology* / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010195:Pancreatitis / Q000150:complications* / Q000276:immunology / Q000473:pathology; D010950:Plasma Cells / Q000276:immunology; D011237:Predictive Value of Tests; D013256:Steroids / Q000627:therapeutic use
chemical_list: D007074:Immunoglobulin G; D013256:Steroids