Hepatitis C virus infection and nonalcoholic steatohepatitis.

Nonalcoholic fatty-liver disease (NAFLD) is one of the most prevalent liver diseases in the Western hemisphere. The rising rates of obesity and diabetes mellitus correlate with the increasing incidence of NAFLD, which is the hepatic manifestation of metabolic syndrome. Hepatitis C virus infection is another common cause of liver disease worldwide. Up to 70% of patients with chronic hepatitis C (CHC) will have concomitant steatosis. The presence of NAFLD has been implicated as a cause of lower viral response rates in CHC patients who are treated with pegylated interferon and ribavirin. This review will focus on the factors that lead to NAFLD in the setting of hepatitis C virus infection, including viral and host factors-in particular, inflammatory mediators, cytokines, and lipid peroxidation. This paper will also discuss the implications of NAFLD and nonalcoholic steatohepatitis regarding fibrosis progression, risk of hepatocellular carcinoma, and limitations with antiviral therapy.