Autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is a rare autoimmune disease. It represents 2-4% of all chronic pancreatitis. It occurs in two forms differing in geographical distribution, histological picture, and other characteristics:
 * Type 1 AIP (lymphoplasmocytic sclerosing pancreatitis) is an IgG4 associated disease located in the pancreas. It rather affects elderly patients.
 * Type 2 AIP affects younger patients, the risk of relapse is significantly lower than in type 1 AIP. It is often associated with idiopathic intestinal inflammation.

Both types are characterized by painless jaundice, sudden diabetes mellitus, radiologically detectable pancreatic enlargement, and a history of autoimmune disorders. Both types respond very well to corticosteroid therapy.

The HISORt diagnostic criteria from the Mayo Clinic (2006) for autoimmune pancreatitis are determined in such a way that at least one of the symptom groups must be met for the diagnosis of AIP.

Histopathological finding: at least one of the following must be met: Clinical finding: all criteria must be met
 * 1) lymphoplasmacytic infiltrate with storiform fibrotization and obliterative phlebitis
 * 2) lymphoplasmacytic infiltrate with storiform fibrotization and at least 10 IgG4 + plasma cells at the highest magnification
 * 1) CT resp. MRI displays diffusely enlarged pancreas with delayed and peripheral gain
 * 2) diffusely enlarged and irregular ductus pancreaticus
 * 3) the IgG4 level exceeds 1.4 g/l

Therapeutic experiment: all criteria must be met
 * 1) unexplained pancreatic disease after excluding other known causes
 * 2) elevation of serum IgG4 or histologically confirmed the involvement of another organ with IgG4 + cell infiltration
 * 3) remission or significant improvement in pancreatic and/or non-pancreatic disorders after corticosteroid therapy

Related Articles

 * Chronic pancreatitis
 * IgG4 associated disease