Diabetes associated with autoimmune pancreatitis: new insights into the mechanism of β-cell dysfunction.

A high proportion of patients with autoimmune pancreatitis (AIP) have diabetes. The decreased β-cell function in active AIP, which leads to diabetes, can sometimes be reversed by corticosteroid treatment. However, the immunological mechanisms causing this β-cell dysfunction are largely unclear. Our recent studies on AIP complicated with diabetes, and data from other animal models of AIP, suggest the presence of distinct mechanisms responsible for β-cell damage in AIP. The presence of immunological cross-reactivity against antigens that are localized both in exocrine pancreatic tissue and β-cells may explain the concomitant occurrence of pancreatitis and β-cell damage in AIP.