Cyclooxygenase-2 overexpression is associated with clinical outcome in biliary atresia

The purpose of this study was to investigate the association between cyclooxygenase-2 (COX-2) expression and clinical outcome in biliary atresia (BA) patients.

Six months after surgery, twenty-eight BA patients were divided into three groups according to their liver function tests: group A with satisfactory liver function (n=11), group B with moderate liver dysfunction (n=8), and group C with severe liver dysfunction (n=9). COX-2 expression was determined by immunohistochemistry. Choledochal cysts (n=5) and normal liver samples (n=4) served as controls.

Our data have shown that the intrahepatic biliary epithelium in BA specimens expressed COX-2. The mean immunoreactive score of COX-2 in BA patients was significantly higher than that in choledochal cyst and normal liver (4.0+/-0.6, 0.9+/-0.3, and 0.7+/-0.3, respectively, p<0.002). Strong expression of COX-2 was observed in BA patients with severe liver dysfunction. Subgroup analysis showed that the mean COX-2 immunoreactive scores of patients in group A, B, and C were 2.1+/-0.6, 3.6+/-1.1, and 5.9+/-0.9, respectively. The COX-2 immunoreactive score in BA patients with severe liver dysfunction was higher than in patients with satisfactory liver function (p<0.005).

Increased COX-2 expression of biliary epithelial cells at the time of Kasai operation was associated with an adverse therapeutic outcome in BA, suggesting that COX-2 could play a plausible role in the liver pathology of BA.