Digestive Diseases News
Winter 2007

Research News

Study Examines Racial Differences in Response to Hepatitis C Therapy

African Americans with chronic hepatitis C genotype 1 had half the response rate of non-Hispanic Caucasians to combination drug therapy, which could not be explained by clinical patient characteristics, disease severity, or amount of medication taken, according to a recent study published in Gastroenterology.

Researchers often attribute the poor response to hepatitis C therapy to a failure to take the full doses of interferon and ribavirin. The side effects of these drugs can be troublesome, causing patients to reduce or discontinue the medication. In this study of 196 African Americans and 205 Caucasians, 36 percent of the patients had at least one dose reduction, while 17 percent discontinued therapy early.

However, drug reduction and discontinuation rates were similar among African American and Caucasian participants, making the changes in prescribed medication doses an unlikely reason for the racial differences in medication response rate, according to the study.

Even after controlling for important factors associated with a combination therapy response, race was an independent determinant of response.

Ongoing Studies

Ancillary studies to address these potential causes for nonresponse are ongoing, according to Charles Howell, M.D., chairman of the Virahep-C Steering Committee, who discussed the results at the Digestive Diseases and Nutrition subcommittee meeting during the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Advisory Council Meeting in September.

The study, “Peginterferon and Ribavirin Treatment in African American and Caucasian American Patients With Hepatitis C Genotype 1,” was a multicenter treatment trial that recruited patients at eight U.S. clinical centers between July 2002 and December 2003.

About 3.2 million Americans have chronic hepatitis C virus (HCV) infection, which is the leading cause of chronic liver disease and the most common cause of liver transplantation in the United States.

African Americans have a higher prevalence of HCV infection and are more likely to have genotype 1 than other racial groups, according to the study. Yet despite this prevalence, African Americans have been underrepresented in most hepatitis C therapy trials, making it hard to estimate response rates accurately within this population.

More information on chronic hepatitis C is available from the National Digestive Diseases Information Clearinghouse at www.digestive.niddk.nih.gov/ddiseases/pubs/chronichepc/index.htm.

[Top]

NIH Publication No. 07–4552
March 2007