Cyclooxygenase-2 Overexpression is Associated with Clinical Outcome in Biliary Atresia

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