Genes Affect Response to Hepatitis C Treatment
New research may explain why Caucasians respond better to treatment of hepatitis C than African-Americans.
A study released in the journal Nature reports that a genetic variation is associated with an approximately twofold change in response to treatment. The variation is a polymorphism near the IL28B gene, encoding interferon-lambda-3 (IFN-lambda-3).
Chronic infection with hepatitis C virus (HCV) affects 170 million people worldwide. It is the leading cause of cirrhosis in North America. The recommended treatment for chronic infection involves a 48-week course of interferon combined with ribavirin. Many patients are not cured even with treatment.
The study was done on 1,137 patients given standard treatment on hepatitis C. Hepatitis C patients with the genetic variation are more likely to have a positive response to treatment. They are more likely to tolerate the treatment. Those with the variation are more likely to be of European descent.
The researchers hope to use this information to improve treatment.
Hepatitis C is a liver disease caused by the hepatitis C virus (HCV). HCV infection sometimes results in an acute illness, but most often becomes a chronic condition that can lead to cirrhosis of the liver and liver cancer.
The HCV virus is transmitted by contact with the blood of an infected person, primarily through sharing contaminated needles to inject drugs.
Approximately 70%–80% of people with acute hepatitis C do not have any symptoms. Some people, however, can have mild to severe symptoms soon after being infected, including fever, fatigue, loss of appetite, nausea, vomiting, abdominal pain, dark urine, clay-colored bowel movements, joint pain, and jaundice (yellow color in the skin or eyes).
Genetic variation in IL28B predicts hepatitis C treatment-induced viral clearance; Dongliang Ge, Jacques Fellay, Alexander J. Thompson, Jason S. Simon, Kevin V. Shianna, Thomas J. Urban, Erin L. Heinzen, Ping Qiu, Arthur H. Bertelsen, Andrew J. Muir, et al.; Nature (16 August 2009) doi:10.1038/nature08309 letter