Nonalcoholic steatohepatitis: a toxic liver disease in industrial workers

Aims: Occupational/environmental exposure to hepatotoxins has recently been implicated in nonalcoholic steatohepatitis (NASH). The aims of this study were to determine the presence and frequency of NASH in a large group of wo rkers chronically exposed to several volatile petrochemical products in an industrial area in north-east Brazil and to observe its course in workers r emoved from the work environment. Methods: 1500 asymptomatic workers were s creened with standard liver blood tests during 1994-5. Those with elevated transaminases (>3x normal) on 3 occasions were evaluated further both clini cally and with serum HBsAg, anti-HCV, ferritin, lipids and autoantibody det ermination. Patients with either no etiological diagnosis, positive HBsAg/a nti-HCV serology and/or excess alcohol intake underwent liver biopsy. Those with obesity, diabetes or an isolated abnormal GGT were excluded. Of worke rs diagnosed as having NASH (compatible histology and no excess alcohol int ake), a proportion were removed from the work environment and evaluated mon thly with liver blood tests and a repeat liver biopsy 8-14 months later. Re sults: 112 workers had abnormal transaminases and 32 fulfilled the criteria for liver biopsy. 20 of these were classified as NASH, the remainder had v iral hepatitis (n=6), alcoholic liver disease (n=5) or portal vein thrombos is (n=1). In all of the 10/20 who were removed from the work environment, t heir aminotransferases and GGT gradually decreased and their histology impr oved. Conclusions: These results demonstrate that NASH can occur following chronic exposure to volatile petrochemical substances in the workplace. Exp osed workers should be regularly screened for the presence of liver damage and ideally removed from the work environment where possible.