Clinical Significance of B Cell-Activating Factor in Autoimmune Pancreatitis

Objectives: Overexpression of B Cell-activating factor (BAFF) is involved in autoimmunity, but little is known about its role in autoimmune pancreatitis (AIP). The aim of this study was to investigate the role of BAFF in the diagnosis and pathogenesis of AIP. Methods: Patients with AIP (n - 19) were compared with 2 disease control groups (chronic pancreatitis [ n = 17] and pancreatic cancer [ n = 15]) and a healthy subject group (n - 19). Serum BAFF levels were assessed using an enzyme-linked immunosorbent assay. The expressions of BAFF and BAFF receptor in the pancreatic tissue of patients with AIP were estimated using immunohistochemistry. Results: Mean serum BAFF levels were higher in the patients with AIP than in the patients with chronic pancreatitis, the patients with pancreatic cancer, and the healthy subjects (P < 0.0001 for all groups). Using the cutoff value of 1389 pg/mL, the sensitivity and specificity to differentiate AIP from disease and healthy controls were 89.5% and 92.2%, respectively. Glucocorticoid therapy decreased serum BAFF levels below 1389 pg/mL in all patients with AIP (P < 0.0001). B Cell-activating factor and BAFF receptor were expressed on cells infiltrating the pancreas of patients with AIP. Conclusions: B Cell-activating factor could be a novel marker for diagnosis and treatment response in AIP and may contribute to its pathogenesis.