Hepatitis C and alcohol: interactions, outcomes, and implications.

BACKGROUND: Alcoholism and chronic hepatitis C (HCV) infection are common causes of liver disease worldwide. Hepatitis C virus and alcohol use frequently coexist, and together lead to more rapid progression of liver disease. GOALS: To critically review the literature pertaining to the combined effects of alcohol and HCV, focusing primarily on how alcohol influences the natural history, pathogenesis, and treatment of HCV liver disease. STUDY: A thorough review of the English literature was conducted, using a MEDLINE-based computerized literature search and review of cited references.
RESULTS: Hepatitis C virus is prevalent in unselected alcoholic populations (14-36%) and in alcoholic individuals with liver disease (< or =51%). Hepatitis C virus-infected individuals who drink alcohol in excess have more severe histologic injury, more rapid disease progression, and a higher frequency of cirrhosis and hepatocellular carcinoma. Alcohol use also appears to decrease response rates to interferon therapy. The mechanisms of interaction between alcohol and HCV are not fully understood, but they likely include the effects of alcohol on the host immune system and the virus and on other factors possibly related to HCV liver disease and hepatic carcinogenesis.
CONCLUSIONS: Alcohol use and HCV infection frequently coexist. Although there is ample evidence that alcohol use adversely affects the natural history of HCV liver disease, how the two interact is not well understood. Patients with chronic HCV should be encouraged to avoid alcohol; however, the threshold above which alcohol results in accelerated liver disease remains to be determined.