title: Recent advances in autoimmune pancreatitis: type 1 and type 2.
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.
authors.affiliation: Department of Internal Medicine, Tokyo Metropolitan Komagome Hospital, Tokyo, Japan.
authors.forename: Terumi
authors.initials: T
authors.lastname: Kamisawa
authors.forename: Suresh T
authors.initials: ST
authors.lastname: Chari
authors.forename: Markus M
authors.initials: MM
authors.lastname: Lerch
authors.forename: Myung-Hwan
authors.initials: MH
authors.lastname: Kim
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Gress
authors.forename: Tooru
authors.initials: T
authors.lastname: Shimosegawa
mesh_terms: D001327:Autoimmune Diseases / Q000145:classification / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology; D003937:Diagnosis, Differential; D019468:Disease Management; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics; D007074:Immunoglobulin G / Q000097:blood; D007155:Immunologic Factors / Q000627:therapeutic use*; D054539:Medication Therapy Management; D020556:Neutrophil Infiltration; D010179:Pancreas / Q000276:immunology / Q000473:pathology; D050500:Pancreatitis, Chronic / Q000145:classification / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology; D010950:Plasma Cells / Q000276:immunology; D011110:Polymorphism, Genetic; D055502:Secondary Prevention
chemical_list: D005938:Glucocorticoids; D007074:Immunoglobulin G; D007155:Immunologic Factors
keywords: Pancreatitis