Republished: Recent advances in autoimmune pancreatitis: type 1 and type 2. Issue 1059 (11th December 2013)

• Record Type: Journal Article
• Authors: Kamisawa, Terumi; Chari, Suresh T; Lerch, Markus M; Kim, Myung-Hwan; Gress, Thomas M; Shimosegawa, Tooru
• Is Part Of: Postgraduate medical journal. Volume 90:Issue 1059(2014)
• Page Start: 18
• Page End: 25
• Publication Date: 2013-12-11
• Subjects: Pancreatitis; Medicine -- Periodicals; 610
• DOI: 10.1136/postgradmedj-2012-304224rep
• Languages: English
• ISSNs: 0032-5473

Abstract

Abstract: Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis characterised clinically by frequent presentation with obstructive jaundice, histologically by a lymphoplasmacytic infiltrate with fibrosis, and therapeutically by a dramatic response to steroids. When so defined, AIP can be sub-classified into two subtypes, 1 and 2. Recent international consensus diagnostic criteria for AIP have been developed for diagnosis of both forms of AIP. Type 1 AIP is the pancreatic manifestation of a multiorgan disease, recently named IgG4-related disease. Little is known about the pathogenesis of either form of AIP. Despite frequent association of type 1 AIP with elevated serum IgG4 levels and infiltration with IgG4-positive plasma cells, it is unlikely that IgG4 plays a pathogenic role in AIP. Type 1 AIP responds to steroids, but there needs to be consensus on treatment regimens for induction and therapeutic end points. Relapses are common, but can be reduced by long-term use of low-dose steroids. Recent reports suggest that immunomodulators (azathioprine, 6-mercaptopurine and mycophenolate mofetil), as well biological agents (the antibody to CD20, rituximab) may have a role in maintaining remission in relapsing type 1 AIP. Future studies should clarify the best management options for treatment of relapses and maintenance of remission. Type 2 AIP is a pancreas-specific disorder not associated with IgG4. It presents in younger individuals equally with obstructive jaundice and pancreatitis. The inflammatory process responds to steroid therapy; relapses are uncommon. The clinical spectrum and long-term outcomes of medically treated type 2 AIP are still being evaluated.