Autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is an increasingly recognized clinical condition. Our objective is to provide a concise review of the advances in the past year in our understanding of AIP.

In a hospital survey from Japan, the prevalence of AIP was estimated at 0.82 per 100,000 individuals. The pathogenesis of AIP remains unclear but a recent report noted that T helper type 2 and T regulatory cells predominantly mediate the immune reaction in AIP. Genetic associations that may predispose to relapse of AIP were reported. Multiple case series further described the clinical profile of AIP and its extrapancreatic manifestations. A large series on immunoglobulin G4 (IgG4)-associated cholangitis noted that patients with IgG4-associated cholangitis presented with obstructive jaundice and had increased serum IgG4 levels and IgG4-positive cells in bile duct biopsy specimens. Tissue IgG4 staining is likely to be a useful adjunct to serological diagnosis. AIP is steroid-responsive but maintaining remission continues to remain challenging. Presently low-dose steroids or immunomodulators are being used but efficacy of these medications remains to be determined.

There has been significant progress in understanding the clinical profile of AIP but knowledge of pathogenesis remains limited. Treatment practices vary widely and management of refractory disease continues to be challenging.