Hepatitis C and Alcohol

by National Institute of Health

Patients infected with the hepatitis C virus (HCV) who drink heavily are likely to suffer more severe liver injury, promoting disease progression to cirrhosis and increasing their risk for liver cancer. Some research, although not conclusive, suggests that even moderate drinking may spur liver damage in HCV-infected patients. Research areas that have the greatest potential for developing more effective treatment options include HCV virology, immunology, animal models, and the mechanisms of liver injury.

Hepatitis C is an infectious liver disease caused by the hepatitis C virus (HCV). The virus, which causes inflammation in the liver and can lead to more serious illness, primarily is spread by intravenous contact with the blood of an infected person. About 4 million people in the United States have been infected, making it the Nation's most common blood-borne disease, resulting in the deaths of between 10,000 and 12,000 people each year. Those at heightened risk for HCV infection include intravenous drug users, people who received blood transfusions or organ transplants before 1992 or clotting factors made before 1987, health care workers who suffer needle-stick accidents, and infants born to mothers who are infected with HCV. Several factors may accelerate the progression of hepatitis C, including older age at the time of infection, male gender, obesity, abnormal accumulation of fat in the liver (a condition known as fatty liver, or steatosis), and excessive alcohol consumption.

This article discusses the mechanisms by which alcohol may exacerbate HCV-infected patients' risk of disease progression, reviews issues in the treatment of alcoholic patients with HCV infection, and addresses important areas of future research.

Epidemiology of Hepatitis C Among Alcoholics

Almost one-third of alcoholics with clinical symptoms of liver disease have been infected with HCV, which is four times the rate of HCV infection found in alcoholics who do not have liver disease. As shown in figure 1, people with more severe liver disease are considerably more likely to test positive for HCV infection than those with less severe liver disease.

Levels of Alcohol Consumption in HCV Patients and the Risk of Further Liver Disease

Several studies have indicated that heavy alcohol consumption accelerates patients' progression from chronic HCV to cirrhosis (a condition in which fibrous scar tissue replaces healthy liver tissue), and liver cancer (specifically, hepatocellular carcinoma, the most common form of liver cancer). Although fewer studies have examined the effects of moderate drinking on the course of liver disease in HCV patients, there is some indication that alcohol consumption in the moderate-to-heavy range may increase HCV-infected patients' risk of developing liver fibrosis and cirrhosis. Research on whether gender has any effect on alcohol consumption and liver disease progression in HCV patients is very limited.

Cirrhosis

In a study of 2,235 HCV-infected patients, Poynard and colleagues observed that patients who drank heavily (more than 50 grams of alcohol, or 4.2 drinks, per day) (NIAAA defines a standard drink as 11-14 g of alcohol. This corresponds to approximately one shot of 80-proof alcohol.) tended to show much more advanced liver scarring (i.e., fibrosis, a defining feature of cirrhosis) than those who did not drink as heavily. In addition, the researchers identified a group of "rapid fibrosers," who were more likely to be male, heavy drinkers, and infected with HCV after age 40.

Wiley and colleagues observed that HCV-infected patients who drank heavily were significantly more likely to develop cirrhosis than those who were not heavy drinkers. In addition, among patients who did develop cirrhosis, the disease emerged considerably sooner for patients who drank heavily than for those who did not.

Bellentani and colleagues analyzed hepatitis virus markers (including the virus's genetic material, HCV RNA, and antibodies to the virus), alcohol intake, and clinical and biochemical evidence of liver disease in a random sample of 6,917 people in northern Italy. Regardless of HCV status, subjects who were heavy drinkers (which the authors defined as drinking more than 30 g, or 2.5 drinks, per day) for more than 10 years were three times as likely to have cirrhosis than those who were not heavy drinkers. Among HCV-positive subjects, 32 percent of those who were heavy drinkers had cirrhosis, compared with 10 percent of those who were not heavy drinkers. There were five cases of hepatocellular carcinoma, all in the heavier drinking group.

Seeff and colleagues studied 1,030 patients who had been enrolled in a prospective investigation of transfusion-associated HCV conducted in the United States between 1968 and 1980. In a followup investigation conducted an average of 15 years after transfusions had occurred, the researchers found that 17 percent of patients infected with transfusion-associated HCV had developed cirrhosis, compared with 3.2 percent of patients with transfusion-associated non-A, non-B, and non-C hepatitis, and 2.8 percent of uninfected patients. Alcohol use greatly exacerbated patients' risk of progression from chronic hepatitis to cirrhosis. Patients with both transfusion-associated HCV and a history of heavy alcohol use were 31 times more likely to develop cirrhosis than control subjects without a history of alcohol abuse.

Perhaps the most dramatic demonstration that alcohol multiplies HCV-infected patients' risk of cirrhosis came from a study by Corrao and Arico. Of 285 cirrhotic subjects, only 1.4 percent were HCV-positive and nondrinkers, compared with 11.2 percent who were both HCV-positive and heavy drinkers.

People infected with both HCV and HIV are more likely to develop cirrhosis than are patients who are infected only with HCV, and alcoholism further potentiates this mechanism.

About the Author

NIH is the nation's medical research agency - making important medical discoveries that improve health and save lives. The National Institutes of Health (NIH), a part of the U.S. Department of Health and Human Services, is the primary Federal agency for conducting and supporting medical research.