Innate Immunity in Alcohol Liver Disease

Excessive ingestion of alcohol is one of the major causes of chronic liver disease worldwide. Alcoholic liver disease (ALD) encompasses a broad spectrum of diseases ranging from steatosis (fatty liver), steatohepatitis, fibrosis, cirrhosis to hepatocarcinoma. Almost all heavy drinkers develop fatty liver; however, only up to 30% of heavy drinkers may develop more several forms of chronic liver injury such as alcoholic hepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma (O'Shea et al., 2010). Despite extensive research, cellular and molecular mechanisms contributing to the pathogenesis of ALD remain to be fully elucidated. Classically, direct hepatotoxicity and production of reactive oxygen species (ROS) induced by alcohol and its metabolites (e.g. acetaldehyde, acetate) are considered the major causative factors. Nevertheless, growing evidence suggests innate immunity also plays an important role in the pathogenesis of ALD (Byun & Jeong, 2010; Gao et al., 2011; Miller et al., 2011).