Autoimmune pancreatitis

Autoimmune pancreatitis can be classified as:

• type 1—manifestation of systemic immunoglobulin G₄ (IgG₄)–related disease
• type 2—primary pancreatic disorder.

Autoimmune pancreatitis is characterised by abdominal pain, biliary strictures, or by the presence of a pancreatic mass. It can be confused with carcinoma.

If autoimmune pancreatitis is suspected, refer the patient to a gastroenterologist.

Diagnostic features are a pancreatic mass or enlargement seen on imaging, pancreatic duct narrowing, serological evidence of hypergammaglobulinaemia (particularly IgG₄), abnormalities of the biliary tree, typical histological findings (lymphocytic infiltration and fibrosis) and a response to corticosteroid therapy demonstrated through imagingKamisawa, 2009Pannala, 2009.

For more information about IgG₄-related digestive disease, including management, see the European guidelines on IgG4-related digestive disease. Also see Immunoglobulin G4-related disease.