DURHAM, N.C. Many people who undergo treatment for hepatitis C develop hemolytic anemia, a disorder that destroys red blood cells. In some cases, it is so severe they have to reduce their medication or stop therapy altogether. But now, scientists in Duke University's Institute for Genome Sciences & Policy (IGSP) have discovered two genetic alterations linked to a benign enzyme condition that keep some patients anemia-free.
They say the discovery, appearing online in the journal Nature, opens the door to treatment for patients who have never been considered candidates for therapy before and may also hold the key to new drugs that could prevent anemia from developing in the first place.
The protective mechanism is a deficiency in a gene called ITPA. "We found that patients who carried specific functional variants are strongly protected against developing anemia," says David Goldstein, Ph.D., director of the Center for Human Genome Variation in the IGSP and a senior author of the study.
Previous studies had identified the genetic variants as the cause of a deficiency in the production of an enzyme, inosine triphosphatase. But it was only through a genome-wide association study that the Duke team was able to show that these same variants were protective against anemia induced by ribavirin, one of two necessary drugs in hepatitis C treatment.
About 180 million people world-wide are infected with the hepatitis C virus, and about 30 to 40 percent of them could develop some degree of treatment-related anemia, according to John McHutchison, M.D. associate director for research at the Duke Clinical Research Institute and also a senior author. "It's a big problem. Hemolytic anemia reduces the level of hemoglobin in the blood and robs it of its ability to carry oxygen. Anything that could help us predict who is going to become anemic and who is not could help us better manage therapy and give all patients the best chance of a
|Contact: Michelle Gailiun|
Duke University Medical Center