Abstract
In an international multicenter study using international consensus diagnostic criteria for autoimmune pancreatitis (AIP), the proportion of patients with type 2 AIP was lower in Asian (4%) countries than in European (13%) and North American (14%) countries (P<0.001). Although Japanese patients with type 2 AIP and inflammatory bowel disease had no jaundice, they did have a high frequency of abdominal pain compared with type 2 AIP patients in an international multicenter study. Half of the Japanese patients with type 2 AIP and inflammatory bowel disease had pancreas head swelling, and the frequency of stenosis of the lower bile duct was about 10%. Moreover, most patients had long irregular narrowing of the main pancreatic duct, with no pancreatic stones, and the frequency of other organ involvement aside from inflammatory bowel disease was low. Corticosteroid therapy was administered in half of the Japanese patients with type 2 AIP and inflammatory bowel disease, and conservative therapy was administered to one third. The frequency of surgical therapy was low. Type 2 AIP in Japanese patients can be further elucidated by the use of sufficient tissue obtained from core biopsies of the pancreas, and by closer cooperation between clinical physicians and pathologists.
