Autoimmune Pancreatitis and Cholangitis

Autoimmune Pancreatitis and Cholangitis
(IgG4-related systemic disease)

Autoimmune pancreatitis (AIP) is a disease mainly affecting men aged 60-70 yrs. Features of this disease include absence of severe pain (attacks) and of major serum elevation of amylase and/or lipase levels, prominent weight loss, jaundice, imaging studies showing (focal or diffuse) swelling of the pancreas with or without a pancreatic rim, endocrine - and exocrine pancreatic insufficiency, elevated serum IgG4 levels and a favorable response to treatment with corticosteroids. There is an increased prevalence of other auto-immune mediated disorders such as retroperitoneal fibrosis, interstitial nephritis, autoimmune prostatitis, autoimmune sialoadenitis and Sjögren's disease. Given the clinical and radiological features this disease may mimic pancreas cancer.
Currently two subtypes of AIP can be distinguished:
Type 1, the ‘’classical’’ form with elevated serum IgG4 levels, usually elderly males, histologically abundant IgG4-positive plasma cells.
Type 2, also called IDCP (idiopathic ducticentric pancreatitis) or granulocytic epithelial lesion-positive pancreatitis, with normal IgG4, histologically presence of GEL’s (granulocytic epithelial lesions), also other age groups, less frequent than type 1.
AIP can also be accompanied by extrapancreatic intra- and extrahepatic biliary strictures that may mimic cholangiocarcinoma or PSC. This entity has been described as autoimmune pancreatico-cholangitis (APC), autoimmune pancreatitis and cholangitis, IgG4 related pancreatic and biliary disease and IgG4 systemic disease. Present available data indicate that APC is the predominant phenotype of this disease in the Netherlands.

Present studies include:
• multicentre case evaluation of patients with AIP and APC, including response to therapy and long-term prognosis
• evaluation of cases with previous Whipple resection but histology showing benign disease
• assessment of the diagnostic value of IgG, IgG4, IgGE, ANA, ANCA’s and a panel of other antibodies
• analysis of radiological features of AIP versus pancreas cancer
• evaluation of the diagnostic role of EUS