TYPE-2 Autoimmune Pancreatitis
What is type-2 autoimmune pancreatitis?
Pancreatitis that is secondary to destruction of ductal epithelial cells via infiltration of neutrophilic polynuclear compounds.
How is it diagnosed?
Type-2 autoimmune pancreatitis manifests itself mainly as acute, isolated and benign pancreatitis. The sex ratio is one to one, and symptoms generally begin to appear at around age 40. Twenty to thirty percent of patients have a related chronic inflammatory bowel disease (IBD). The serum IgG4 level is normal.
Imaging is used to establish the autoimmune origin (heterogeneity of the pancreatic parenchyma, peripancreatic halo, loss of pancreatic lobulations with “sausage” appearance, irregular diameter of the main pancreatic duct).
A pancreatic biopsy, if performed, will reveal destruction of the ductal epithelial cells by infiltration of neutrophilic polynuclear compounds.
Diagnosis can be complex to perform. It is rare to obtain histological proof after puncture of the pancreas and revelation of a granulocytic epithelial lesion (GEL, a characteristic histological lesion). Diagnosis is thus based on the combination of morphological criteria by X-ray, the presence of related IBD and response to treatment with corticosteroids.
What is its specific treatment?
In case of symptoms, treatment is based on corticosteroids (40 mg/day) for one month, followed by progressive decrease in dosage. In case of resistance to or dependence on corticosteroids, treatment with immunomodulators should be discussed.
Source: Reference Centre for Rare Pancreatic Diseases and Disorders