Gene variation may boost Plavix risk

Two stories that fall under the personalized-medicine umbrella today: Researchers found a genetic variation that could make the blood-thinner Plavix riskier for younger heart attack patients, and, in a separate study, a genetic test was found helpful in predicting which patients would respond to hepatitis C treatment.

First, the Plavix research. According to the study published online in The Lancet, a particular gene variation can make younger heart attack patients more likely to suffer another heart attack, to die, or to develop other heart problems if they receive Plavix therapy.

Now, as you know, Plavix plus aspirin is a standard treatment for patients after a heart attack or stent placement. But some patients don't get the full benefit of the blood thinner--and now, we know why, at least partly. "The variation in response is partly due to genetics, but there are other factors such as age which influence the response," Dr. Robert F. Storey told HealthDay. The solution isn't necessarily a genetic test, Storey said; instead, docs can order a blood test to see if they show a "good anti-clotting response" to Plavix.

Second, the hepatitis C study. Published in the online version of the Journal of Clinical Investigation, the research found that "covariation analysis" could predict the outcome of drug therapy in hep C patients. Researchers identified a chunk of genetic code that appeared to be linked with drug failure.

"The ability to predict such failures prior to treatment could save a great deal of pain and expense for the patient with" hepatitis C virus, Thomas Oh and Charles Rice of Rockefeller University wrote in a journal commentary accompanying the study.

- read the HealthDay story
- check out the article from CBC News