Immunological and molecular aspects of liver fibrosis in chronic hepatitis C virus infection.

Chronic C hepatitis represents a major health problem worldwide, mainly because progression of the tissue damage leads to the development of cirrhosis and hepatocellular carcinoma. In this review we discuss the molecular mechanisms underlying the development of liver fibrosis. In particular we consider some immunologic aspects that regulate the interaction between HCV and the host immune defense. Reflections are made about the roles played by the host capacity to respond to the viral infection during therapy and the consequences of the deposition of extracellular matrix (ECM) proteins leading to the development of fibrosis. The involvement of inflammatory cytokines in regulating the proteolytic remodeling of the liver and the ECM turn-over is essential for the activation of hepatic stellate cells (HSCs), that have an important role in the progression of liver fibrosis. Finally, we analyze one of the aspects involved in the activation of the HSCs, namely the proteolytic remodeling of the surrounding environment.