Researchers at Duke University Medical Center have identified the first genetic marker that predicts response to hepatitis C treatments, and a single letter of DNA code appears to make a huge difference.
“For geneticists, understanding response to treatment for hepatitis C infection has been almost like a Holy Grail,” says David Goldstein, PhD, director of the Center for Human Genome Variation in Duke’s Institute for Genome Sciences & Policy and the senior author of the study.
“The side effects of hepatitis treatment can be brutal, and about half the time, the treatment fails to eradicate the virus. This discovery enables us to give patients valuable information that will help them and their doctors decide what is best for them. This is what personalized medicine is all about.”
The discovery is reported online in the journal Nature.
The new biomarker is a single letter change — a C instead of a T — in a tiny segment of DNA near the IL28B gene. Researchers found it by studying 1671 individuals who participated in the IDEAL study, a multi-center clinical trial that compared the two most widely used therapies among patients with the most common form of the disease in the U.S. and Europe.
McHutchison was the lead investigator of the recently published IDEAL study, which found no clinically meaningful differences in overall viral response among the regimens.
In conducting the current study, Goldstein and his colleagues found that the patients who had the single-letter change in their DNA were significantly more likely to respond to treatment than those who did not have it.
“Eighty percent of those with the favorable response genotype eradicated the virus, while only about 30 percent with the less favorable response genotype did so. With differences of that magnitude, patients considering therapy may want to know what their genotype is before they start treatment,” says Goldstein.
Source: Duke University Health System, USA