Fig. 4.

Immunohistochemistry for T helper type 17 (Th17)-inducible cytokines [interleukin (IL)-6 and IL-1β], a component of IL-23 (IL-23 p19), and caspase 1. IL-6 and IL-1β are expressed in bile ducts and infiltrating cells to various degrees; prominently in the damaged bile ducts of primary biliary cirrhosis (PBC), but faintly or not at all in interlobular bile ducts of chronic viral hepatitis C (CVH-C). Caspase 1, which cleaves IL-1β for its secretion, is also expressed in the damaged bile ducts of PBC. In contrast, IL-23 p19 is constantly expressed in interlobular bile ducts, irrespective of PBC and CVH-C.