Abstract
Osteopontin (OPN) is a multifunctional protein, physiologically expressed in the kidney and bone. OPN expression has been attributed to many pathological conditions including inflammation, angiogenesis, fibrosis, and carcinogenesis.
OPN was found to contribute to the migration of macrophages into necrotic areas in liver tissue and to serve as a key cytokine within the extracellular matrix in the liver, contributing to fibrogenesis. OPN is also involved in the evolution and progression of various cancers, including hepatocellular carcinoma.
Plasma OPN levels were found to predict liver fibrosis in various chronic liver diseases such as nonalcoholic steatohepatitis, alcoholic liver disease, and chronic viral hepatitis. OPN levels correlate significantly with the degree of fibrosis and could serve as a noninvasive biomarker of portal hypertension and as a prognostic parameter in cirrhosis.