Recent advances in autoimmune pancreatitis.

ALTHOUGH THE PATHOGENESIS OF AUTOIMMUNE PANCREATITIS REMAINS UNCLEAR, THIS REPORT PRESENTS RECENT EVIDENCE OF THE CLINICAL ASPECTS OF THIS DISEASE: mild abdominal symptoms, usually without acute attacks of pancreatitis; occasional presence of obstructive jaundice; elevated levels of serum gammaglobulin, immunoglobulin (Ig)G, or IgG4; presence of autoantibodies; diffuse enlargement of the pancreas; irregular narrowing of the pancreatic duct (sclerosing pancreatitis), often with intrapancreatic biliary stenosis or coexisting biliary lesions (sclerosing cholangitis similar to primary sclerosing cholangitis) seen on endoscopic retrograde cholangiopancreatography; fibrotic changes with lymphocyte and IgG4-positive plasmacyte infiltration and obliterative phlebitis; occasional association with other systemic lesions (such as sialadenitis), retroperitoneal fibrosis, and interstitial renal tubular disorders; and response to steroid therapy. Based upon these findings, several sets of diagnostic criteria have been proposed. Further studies and international consensus for diagnostic criteria and pathogenetic mechanisms are needed.