Interleukin 6 in bile as an indicator of liver function after hepatectomy in patients with biliary tract carcinoma

Abstract

Background: Interleukin (IL) 6 is one of the important components of the early signalling pathways leading to liver regeneration, and has been detected in the bile after liver transplantation. IL-6 concentrations in the bile were studied in an attempt to predict liver function after major hepatectomy for biliary tract carcinoma. Methods: This study involved 24 patients without cirrhosis who underwent major hepatectomy for biliary tract carcinoma. The bile was sampled regularly through external biliary drainage tubes. IL-6 concentrations in bile and serum were measured using an enzyme-linked immunosorbent assay. Results: Bile IL-6 concentrations increased 37-fold (from mean (s.e.) 56 (13) pg/ml before hepatectomy to 2071 (398) pg/ml on day 1 after operation) in patients without liver failure after hepatectomy (n = 18) and increased sevenfold (from 71 (24) to 530 (76) pg/ml) in patients with liver failure after hepatectomy (n = 6). The values were significantly lower in patients with liver failure than in those without liver failure (P < 0.05). The bile IL-6 concentration on day 1 after operation exhibited a significant negative correlation with the maximum serum total bilirubin concentration after hepatectomy. Although serum IL-6 concentrations were also increased in both groups after hepatectomy, there was no significant correlation with postoperative liver function. Conclusion: Increased bile IL-6 concentrations after hepatectomy may reflect liver regenerative capacity. Measurement of bile IL-6 concentrations may be clinically useful for the early identification of liver failure after hepatectomy.