Clinical

HCV genotype not to blame for poor interferon response in blacks

Last Updated: 2004-05-27 11:57:30 -0400 (Reuters Health)

By Anthony J. Brown, MD

NEW YORK (Reuters Health) - Blacks with chronic hepatitis C have a lower response rate to interferon than whites, but contrary to what has been suggested in the past this is not due to differences in HCV genotype, the findings from a new study confirm.

HCV genotype 1 is known to be relatively resistant to interferon therapy. Previous reports that have identified an inferior interferon response in blacks have suggested that this was because genotype 1 is more prevalent in this racial group. However, in the new study, which included a similar proportion of blacks and whites with genotype 1 infection, the response rate to interferon was still lower in blacks.

"Based on our findings, we think there is an inherent biologic difference between blacks and whites in how they respond to interferon alpha," lead author Dr. Andrew J. Muir, from Duke University in Durham, North Carolina, told Reuters Health. "We now need to prove that and determine what that difference is--there are theories, but nothing conclusive."

As reported in The New England Journal of Medicine for May 27, Dr. Muir's team compared the outcomes of 100 black and 100 non-Hispanic white patients with chronic hepatitis C who were treated with peginterferon alpha-2b and ribavirin for 48 weeks. In both racial groups, 98% of patients were infected with HCV genotype 1.

The sustained virologic response rate in white patients was 52%, while the rate in their black peers was just 19% (p < 0.001). Black patients also showed significantly lower response rates at 12 weeks and at the end of treatment. Multivariate analysis confirmed that black race was the only significant predictor of an inferior interferon response.

Despite the lower response rate seen in blacks, Dr. Muir said that the findings were somewhat encouraging given that past studies have reported even lower rates in blacks. He credits this to "improvements in hepatitic C therapy that have occurred over the last decade."

"African-American patients with chronic hepatitis C still need to be offered interferon; at present, it's our best available therapy," Dr. Muir noted. Studies are in the works that may identify novel therapies that are more effective in blacks, he added.

N Engl J Med 2004;350:2265-2271.