Clinical analysis of autoimmune-related pancreatitis

OBJECTIVE: Several investigators have reported on autoimmune-related pancre atitis, but the clinical findings and pathophysiology still remain unclear. To clarify it, we analyzed eight patients with autoimmune pancreatitis. METHODS: We evaluated clinical findings in eight patients (four men and fou r women) with autoimmune-related pancreatitis. Patients were aged 45-73 yr (mean, 57.5 yr). We examined blood chemistry and immunological studies, inc luding autoantibodies against lactoferrin or carbonic anhydrase II, and com pared ERCP images with clinical findings. In two patients, we studied the s ubset of lymphocytes infiltrating in the pancreas by immunohistochemistry a nd flow cytometry. RESULTS: Four of eight patients had jaundice, two had renal dysfunction, tw o had abdominal pain, and two had back pain. Three patients were complicate d with other autoimmune diseases. Three patients showed abnormal pancreatic exocrine function by an N-benzoyl-L-tyrosyl-para-aminobenzoic acid excreti on test. Antinuclear antibody was detected in four of eight patients, antil actoferrin antibody in three of six, anticarbonic anhydrase II antibody in two of six, antismooth muscle antibody in two of seven, and rheumatoid fact or in one of eight. All eight patients showed segmental stenosis of the mai n pancreatic duct by ERCP. Four patients showed stenosis of the common bile duct as well as the pancreatic duct. Microscopic findings showed infiltrat ion of CD4-positive lymphocytes around the pancreatic duct, and HLA-DR was expressed on both CD4-positive cells and pancreatic duct cells. In two pati ents, stenosis of the pancreatic duct improved by prednisolone. CONCLUSIONS: Autoimmune mechanism may be involved in some patients with idi opathic pancreatitis associated with hypergammaglobulinemia. (Am J Gastroen terol 2000;95: 2788-2794. (C) 2000 by Am. Coll. of Gastroenterology).