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World J Gastrointest Pharmacol Ther. Nov 6, 2015; 6(4): 199-206
Published online Nov 6, 2015. doi: 10.4292/wjgpt.v6.i4.199
Autoimmune pancreatitis and cholangitis
Niraj Jani, James Buxbaum
Niraj Jani, James Buxbaum, Division of Gastrointestinal and Liver Diseases, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033-1370, United States
Author contributions: Jani N and Buxbaum J contributed equally to this work; they performed a comprehensive chronological review of this topic, prepared the figures, and wrote the paper.
Conflict-of-interest statement: The authors declare no conflict of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: James Buxbaum, MD, Division of Gastrointestinal and Liver Diseases, Keck School of Medicine, University of Southern California, D and T Building Room B4H100, 1983 Marengo Street, Los Angeles, Ca 90033-1370, United States. jbuxbaum@usc.edu
Telephone: +1-323-4095371 Fax: +1-323-4418352
Received: April 28, 2015
Peer-review started: May 6, 2015
First decision: June 2, 2015
Revised: June 22, 2015
Accepted: August 25, 2015
Article in press: August 31, 2015
Published online: November 6, 2015
Processing time: 198 Days and 11.2 Hours
Abstract

Autoimmune pancreatitis (AIP) is part of a systemic fibrosclerotic process characterized by lymphoplasmacytic infiltrate with immunoglobulin G subtype-4 (IgG4) positive cells. It characteristically presents with biliary obstruction due to mass-like swelling of the pancreas. Frequently AIP is accompanied by extra-pancreatic manifestations including retroperitoneal fibrosis, thyroid disease, and salivary gland involvement. Auto-antibodies, hypergammaglobulemia, and prompt resolution of pancreatic and extrapancreatic findings with steroids signify its autoimmune nature. Refractory cases are responsive to immunomodulators and rituximab. Involvement of the biliary tree, termed IgG4 associated cholangiopathy, mimics primary sclerosing cholangitis and is challenging to manage. High IgG4 levels and swelling of the pancreas with a diminutive pancreatic duct are suggestive of autoimmune pancreatitis. Given similarities in presentation but radical differences in management and outcome, differentiation from pancreatic malignancy is of paramount importance. There is controversy regarding the optimal diagnostic criterion and steroid trials to make the diagnosis. Additionally, the retroperitoneal location of the pancreas and requirement for histologic sampling, makes tissue acquisition challenging. Recently, a second type of autoimmune pancreatitis has been recognized with similar clinical presentation and steroid response though different histology, serologic, and extrapancreatic findings.

Keywords: Immunoglobulin G; Pancreatitis, chronic; Pancreatitis; Pancreatitis, sclerosing cholangitis, and sicca complex; Sclerosing cholangitis; Retroperitoneal fibrosis

Core tip: Autoimmune pancreatitis is a component of a systemic immunoglobulin G subtype-4 mediated disease which also impacts the bile duct, salivary glands, kidney, and numerous other sites. It presents with jaundice and pancreas mass but it responds promptly to steroids and immunomodulators. A careful diagnostic approach is mandatory as autoimmune pancreatitis and its biliary manifestations closely resemble pancreas cancer and primary sclerosing cholangitis, diseases which have a more ominous course.