The diagnostic significance of serum IgG4 levels in patients with autoimmune pancreatitis: a UK study.

Background: Autoimmune pancreatitis (AIP) is recognised as an end organ manifestation of the systemic condition known as IgG4-sclerosing disease. One major characteristic of this disease, regardless of its location in the body, is the presence of high levels of circulating serum IgG, in particular IgG4 antibody. In the case of AIP, differential diagnosis from other conditions of the pancreas and biliary system, particularly cancers, can be difficult, but could result in avoiding invasive procedures and surgery.