Genetic variation in an interferon gene is associated with treatment response in individuals with chronic hepatitis C virus (HCV), according to two papers published online in this week\'s Nature Genetics. The studies may help to inform clinical decisions for treatment.
Hepatitis C, an infectious disease affecting the liver and a leading cause of liver disease, has a worldwide prevalence of nearly 300 million. The current standard treatment procedure for chronic HCV is combined therapy with pegylated interferon-alpha and ribavirin for a period of 48 weeks. This treatment can have serious adverse side effects and only about 40-50% of individuals infected with HCV show a positive response to it.
Jacob George, Masashi Mizokami and their respective colleagues examined the genomes of hundreds of individuals receiving treatment for chronic HCV. They report genetic variants in the region of the IL28B gene are associated with treatment response. IL28B encodes an interferon-lambda that is involved with suppression of viruses including HCV. There has already been an early clinical trial for another interferon-lambda, IL29, for chronic HCV.
The current studies renew interest in therapies which involve this type of interferon, and suggest that combined treatment with interferon-alpha and interferon- lambda may prove a more effective treatment. They also highlight the potential benefits of individualized treatment, including the prediction of which patients are more likely to benefit, sparing others the cost and side effects associated with treatment.