[Diagnostic criteria for non-alcoholic steatohepatitis]

Nonalcoholic fatty liver disease (NAFLD) is now emerging as the most common liver disease in Japan. NAFLD is mainly comprised of simple fatty liver that is considered benign, though some patients have nonalcoholic steatohepatitis (NASH), which can progress to cirrhosis and hepatocellular carcinoma. The diagnosis of NASH was based on the following criteria: (1) intake of less than 20 g of ethanol per day, (2) biopsy proven steatohepatitis; steatosis, inflammatory infiltrates, and ballooning degeneration with or without Mallory bodies or pericellular/perivenular fibrosis, (3) appropriate exclusion of other liver diseases. The detection of NASH is usually delayed, since there are no serum surrogate markers for NASH, and a definitive diagnosis requires a liver biopsy.