Mechanisms of synergy between alcohol and hepatitis C virus

Since the discovery of the hepatitis C virus (HCV), extensive literature has emerged on alcohol and HCV interaction.

To understand the impact of alcohol and HCV infection on the severity of liver disease and the mechanisms of interaction between the two.

Of 1269 articles (1991 to 2006) searched through MEDLINE and cited cross references, 133 were thoroughly reviewed to assess: (a) prevalence of combined alcohol use and HCV, (b) severity of liver disease (c) treatment response, and (d) mechanisms of interaction between HCV and alcohol. Data on study design, patient demographics, diagnostic tests used, and study outcomes were extracted for critical analysis.

Prevalence of HCV is 3-fold to 30-fold higher in alcoholics compared with the general population. Patients with HCV infection and alcohol abuse develop more severe fibrosis with higher rate of cirrhosis and hepatocellular cancer compared with nondrinkers. Increased oxidative stress seems to be the dominant mechanism for this synergism between alcohol and the HCV. Abstinence is the key to the management of liver disease due to HCV and alcohol. Data have shown that lower response rates to interferon in alcoholics with HCV infection are likely due to noncompliance.

Alcoholics with HCV infection have more severe liver disease compared with nondrinkers. Patients should be encouraged to enroll in rehabilitation programs so as to improve treatment adherence and response.