Autoimmune Pancreatitis May 25, 2005

Autoimmune Pancreatitis May 25, 2005

This disease has only recently been named, with Professor Kawamo Shin of Shinshu University in Japan being the first to introduce it. Among male patients, those in middle and old age account for 83%, with an average age of 62.2 years. Jaundice occurs in 68% of cases, pancreatic discomfort in 78%, while severe pain is relatively rare. Eighty percent of patients show abnormalities in serum enzyme levels, immunoglobulin levels, and positive autoantibodies. Sixty-six percent of patients test positive in the exocrine pancreatic function test (BT-BAPA), and 51% have HbA1c ≥ 5.8; ultrasound shows pancreatic swelling with hypoechoic changes; CT shows pancreatic swelling with straight edges and capsule-like changes; ERCP shows irregular narrowing of the pancreatic duct accompanied by narrowing of the distal bile duct, with about 50% of patients having diffuse narrowing of the pancreatic duct; histological examination reveals fibrosis with lymphocyte and plasma cell infiltration, as well as obstructive phlebitis. The HLA antigens DR4 and DQ4 subtypes are closely related to this disease and are still under investigation. A significant increase in IgG4 is another characteristic. The rise in globulin levels is another feature.