Immunohistochemical localization of antigen presenting cells in liver from patients with primary biliary cirrhosis; highly restricted distribution of CD83-positive activated dendritic cells.

In order to have insights into the abnormal immune regulation in primary biliary cirrhosis (PBC), different types of antigen presenting cells (APC) were localized immunohistochemically in liver specimens from 26 patients with PBC and compared with the distributions of APC from 11 and 10 patients with chronic hepatitis C (CH-C) and large bile duct obstruction, respectively. In all diagnostic conditions, 30-90% of the infiltrating cells were positive for HLA DR. In PBC, the numbers of interdigitating cells (IDC) were significantly higher than the numbers of CD83-positive dendritic cells (DC) (34.0 +/- 38.8 vs. 5.5 +/- 7.1/specimen, mean +/- SD, p < 0.05). On the other hand, the numbers of IDC (14.2 +/- 20.0/specimen) and CD83-positive DC (7.9 +/- 8.7/specimen) were almost similar in CH-C (p > 0.05). Positive stainings for IDC and CD83-positive DC were rarely seen in large bile duct obstruction. This is the first report on the existence of activated CD83-positive DC in PBC. The significantly increased numbers of IDC and the highly restricted distributions of CD83-positive DC in PBC indicate that activated DC may play a role in the abnormal immune pathogenesis of PBC.