Abstract/Text: BACKGROUND: Steroid therapy is currently common treatment for autoimmune pancreatitis (AIP); however, indications of steroid therapy have yet to be established, and the clinical course after steroid therapy is unknown.
METHODS: A total of 23 patients with AIP were subdivided into 4 groups according to the initial treatments undertaken. They were treated with pancreatoduodenectomy on suspicion of pancreatic tumor in 6 patients, choledochoduodenostomy with pancreatic biopsy in 4 patients, supportive therapy in 3 patients, and steroid therapy in 10 patients. Clinical course of AIP in each group was examined.
RESULTS: Prognosis of the AIP patients is almost good except for the 2 patients who progressed to pancreatic insufficiency after resection. Two patients without jaundice improved spontaneously. Steroid therapy was effective in all patients treated, but pancreatic atrophy developed in 5 of these patients. Steroid therapy improved insulin secretion and glycemic control in 4 of 7 diabetes mellitus (DM) patients.
CONCLUSION: To avoid futile surgery, in relatively elderly male patients with obstructive jaundice suggestive of pancreatic carcinoma, preoperative clinical suspicion of AIP is mandatory. Indications of steroid therapy for AIP are thought to be obstructive jaundice due to stenosis of the bile duct, other associated systemic autoimmune, and DM coincidental with AIP.

Abstract/Text: BACKGROUND: Steroid therapy is currently common treatment for autoimmune pancreatitis (AIP); however, indications of steroid therapy have yet to be established, and the clinical course after steroid therapy is unknown.
METHODS: A total of 23 patients with AIP were subdivided into 4 groups according to the initial treatments undertaken. They were treated with pancreatoduodenectomy on suspicion of pancreatic tumor in 6 patients, choledochoduodenostomy with pancreatic biopsy in 4 patients, supportive therapy in 3 patients, and steroid therapy in 10 patients. Clinical course of AIP in each group was examined.
RESULTS: Prognosis of the AIP patients is almost good except for the 2 patients who progressed to pancreatic insufficiency after resection. Two patients without jaundice improved spontaneously. Steroid therapy was effective in all patients treated, but pancreatic atrophy developed in 5 of these patients. Steroid therapy improved insulin secretion and glycemic control in 4 of 7 diabetes mellitus (DM) patients.
CONCLUSION: To avoid futile surgery, in relatively elderly male patients with obstructive jaundice suggestive of pancreatic carcinoma, preoperative clinical suspicion of AIP is mandatory. Indications of steroid therapy for AIP are thought to be obstructive jaundice due to stenosis of the bile duct, other associated systemic autoimmune, and DM coincidental with AIP.

Abstract/Text: Autoimmune pancreatitis (AIP) is a peculiar type of pancreatitis of presumed autoimmune etiology. Many new clinical aspects of AIP have been clarified during the past 10 years, and AIP has become a distinct entity recognized worldwide. However, its precise pathogenesis or pathophysiology remains unclear. As AIP dramatically responds to steroid therapy, accurate diagnosis of AIP is necessary to avoid unnecessary surgery. Characteristic dense lymphoplasmacytic infiltration and fibrosis in the pancreas may prove to be the gold standard for diagnosis of AIP. However, since it is difficult to obtain sufficient pancreatic tissue, AIP should be diagnosed currently based on the characteristic radiological findings (irregular narrowing of the main pancreatic duct and enlargement of the pancreas) in combination with serological findings (elevation of serum gamma-globulin, IgG, or IgG4, along with the presence of autoantibodies), clinical findings (elderly male preponderance, fluctuating obstructive jaundice without pain, occasional extrapancreatic lesions, and favorable response to steroid therapy), and histopathological findings (dense infiltration of IgG4-positive plasma cells and T lymphocytes with fibrosis and obliterative phlebitis in various organs). It is apparent that elevation of serum IgG4 levels and infiltration of abundant IgG4-positive plasma cells into various organs are rather specific to AIP patients. We propose a new clinicopathological entity, "IgG4-related sclerosing disease", and suggest that AIP is a pancreatic lesion reflecting this systemic disease.

Abstract/Text: OBJECTIVES: It is of utmost importance that autoimmune pancreatitis (AIP) be differentiated from pancreatic cancer (PC) because some AIP cases undergo unnecessary laparotomy or pancreatic resection on suspicion of PC. This study aimed to develop an appropriate strategy for differentiating between AIP and PC.
METHODS: Clinical, serological, and radiological features of 17 AIP patients forming a masslike lesion on pancreas head and 70 patients with pancreatic head cancer were compared.
RESULTS: Numerous findings can be used to distinguish between AIP and PC, and the following are more likely in AIP: fluctuating jaundice; elevated serum IgG4 levels; delayed enhancement of the enlarged pancreas and a capsule-like low-density rim on computed tomography; long or skipped narrowed portion with side branches of the main pancreatic duct without upstream dilatation on endoscopic retrograde pancreatography, extrapancreatic lesions, such as stenosis of the intrahepatic bile duct, salivary gland swelling, and retroperitoneal mass; and responsiveness to steroid therapy.
CONCLUSIONS: In elderly male patients presenting with obstructive jaundice and a pancreatic mass, AIP should be considered in the differential diagnosis. Based on a combination of clinical, serological, and radiological findings, AIP can be differentiated from PC. An algorithm for management of patients with a masslike lesion on pancreas head is presented.

Abstract/Text: BACKGROUND: Based on histological and immunohistochemical examinations of various organs of patients with autoimmune pancreatitis (AIP), a new clinicopathological entity, IgG4-related systemic disease, was proposed. This study aimed to clarify clinical utility of serum IgG4 levels in differentiating AIP from other pancreatobiliary diseases, clinical utility of serum IgG4 levels in differentiating Mikulicz's disease from other salivary gland disorders, as well as in identifying other IgG4-related diseases.
METHODS: Serum IgG4 levels were measured in 468 patients.
RESULTS: The median serum IgG4 level was significantly greater in AIP (301.5mg/dl) than in other pancreatobiliary diseases (p<0.01). Using the cutoff value of 119 mg/dl that was determined on the basis of this study's ROC curve data, the sensitivity and specificity to distinguish AIP from pancreatic cancer were 82.1% and 94.8%, respectively. The median serum IgG4 level was significantly greater in Mikulicz's disease (357.0mg/dl) than in other salivary gland diseases (p<0.01). Of 75 patients with elevated serum IgG4 levels, 15 had diseases other than pancreatobiliary and salivary gland diseases.
CONCLUSIONS: Serum IgG4 levels were useful for diagnosing AIP and Mikulicz's disease. Some diseases with serum IgG4 level elevations may be lesions of IgG4-related systemic disease without manifestations of AIP and Mikulicz's disease.