Liver biopsy in alcoholic and non-alcoholic steatohepatitis patients.

Alcoholic liver disease and non-alcoholic liver disease share a similar histological spectrum that starts with 'simple' steatosis, and may be accompanied by inflammation. Alcoholic steatohepatitis and non-alcoholic steatohepatitis (NASH) are progressive forms of alcoholic liver disease and non-alcoholic liver disease, respectively, and can evolve into cirrhosis. The currently accepted minimum diagnostic criteria for steatohepatitis include steatosis, lobular inflammation and hepatocellular injury, but not fibrosis. Steatosis involving more than 5% of hepatocytes is required for the diagnosis of non-alcoholic fatty liver disease, but is not necessary for the diagnosis of alcoholic liver disease. Lobular inflammation is usually mild and frequently consists of a mixed, acute and chronic, inflammatory cell infiltrate composed of neutrophils and mononuclear cells. The presence of large numbers of neutrophils favors an alcoholic etiology. Hepatocellular injury in fatty liver disease usually occurs in the form of ballooning, but it can also present as apoptotic (acidophilic) bodies and lytic necrosis. The characteristic pattern of fibrosis in non-cirrhotic steatohepatitis is pericellular/perisinusoidal and is the result of deposition of collagen in the space of Disse. In both alcoholic steatohepatitis and NASH, sinusoidal collagen formation is the result of hepatic stellate cell activation that, in NASH, has been correlated with the grade of steatosis and fibrosis.