Direct Markers of Liver Fibrosis

AbstractLiver fibrosis is a chronic condition that originates as a result of prolonged hepatic injury. Liver fibrosis is caused mainly by Schistosomiasis, chronic hepatitis C and B viral infections, non-alcoholic fatty liver disease, alcoholic liver disease, cholestatic and autoimmune liver diseases. Hepatic stellate cells are the master cells in the fibrosis process regardless of the cause. HSCs activation involves two separate stages: the initiation stage and the perpetuation stage. The activated HSCs up-regulate gene expression of extracellular matrix elements, matrix-degrading enzymes, and their inhibitors. The components of fibrotic ECM or inflammatory mediators implicated in either the process of fibrosis or degradation of scar tissue could be used as direct markers of fibrosis. Direct indices of fibrosis are classified into direct markers associated with matrix deposition such as HA and laminin, direct markers associated with matrix degradation such as MMPs and TIMPs, and Cytokines and chemokines linked to hepatic fibrosis such as TGF-𝛽1 and PDGF. The validation of these markers for use in clinical practice instead of liver biopsy should be balanced against the possibility of misleading results of these markers as they are affected by factors other than fibrosis.