Implication of adhesion molecules in inflammation of the common bile duct in patients with secondary cholangitis due to biliary obstruction

The aim of the present study was to investigate the participation of the adhesion molecules and their ligands in the inflammatory process in secondary cholangitis.

Biopsy specimens were collected from the common bile duct from 29 patients with extrahepatic bile obstruction. Immunohistochemistry was used to study the expression of adhesion molecules (ICAM-1, VCAM-1, E-selectin, LFA-1, PECAM-1, Mac-1, and VLA-4). The patients were categorized into 2 groups - chronic exacerbated cholangitis and chronic sclerotic cholangitis.

An increased ICAM-1 expression was demonstrated and also de novo VCAM-1 and E-selectin appearance on the endothelium of microvessels in chronic exacerbated cholangitis. The inflammatory cells were strongly LFA-1-, Mac-1- positive. In chronic sclerotic cholangitis the E-selectin expression persisted on vascular endothelium in the fibrous tissue and reduced inflammatory infiltrate showed LFA-1 and VLA-4 positivity. The newly formed vessels in the fibrous connective tissue were PECAM-1-positive.

From these results, it could be concluded that in chronic exacerbated cholangitis with complete bile obstruction the firm adhesion is mediated by ICAM-1/LFA-1 and ICAM-1/Mac-1 and less by VCAM-1/VLA-4 pathways. In chronic sclerotic cholangitis, caused by incomplete obstruction, the firm adhesion was maintained by ICAM-1/LFA-1 and less by VCAM-1/VLA-4 pathways. It seems likely that PECAM-1 and VCAM-1/VLA-4 play additional roles in neutrophil recruitment.