Role of Osteopontin in Calcification in Autoimmune Pancreatitis

Objectives The aim of the present study was to determine the potential for pancreatic calcification in autoimmune pancreatitis by investigating osteopontin and CD44 expression. Methods Human pancreatic tissues in normal pancreas, chronic pancreatitis, and autoimmune pancreatitis were obtained from the surgical specimens of 42 patients. Pancreatic tissues from male Wistar Bonn/Kobori rats were also used as an animal autoimmune pancreatitis model. Results The incidences of osteopontin expression in centroacinar cells in chronic pancreatitis with calcification and in autoimmune pancreatitis were significantly greater than that in normal pancreas (P < 0.05). Some cases of chronic pancreatitis and autoimmune pancreatitis expressed CD44 in centroacinar cells and ductal cells. In male Wistar Bonn/Kobori rats, the inflammatory area and percentage of osteopontin-CD44-positive cells increased with advancing age (P < 0.01 or 0.05). Conclusions These results suggest that autoimmune pancreatitis has the potential for pancreatic calcification over a long-term clinical course.