Serum BAFF and APRIL levels in patients with PBC.

B-cell-activating factor belonging to the TNF family (BAFF) and a proliferation-inducing ligand (APRIL) are known to be involved in the occurrence of autoimmune diseases. We assessed serum levels of these cytokines in PBC patients. Serum BAFF levels were significantly higher in PBC patients than in healthy controls (1253.9+/-741.4 vs. 722.8+/-199.2 pg/ml; p<0.0001) and HCV-infected patients (1253.9+/-741.4 vs. 871.0+/-251.1 pg/ml; p=0.015). Whereas changes in serum APRIL levels were not significant among these groups, there was a significant correlation between BAFF and AST (R=0.278, p=0.003) or total bilirubin (R=0.363, p=0.0006) in PBC patients. Furthermore, serum BAFF levels were elevated in PBC patients with advanced interface hepatitis. Our data indicate that serum levels of BAFF and APRIL are differentially regulated and serum BAFF levels are significantly elevated in PBC patients. These findings suggest that BAFF may serve as a modulator of the clinical and/or serological manifestation in PBC patients.