Patient's Genes May Impact Hepatitis C Outcomes
Dec. 17, 1999 (Indianapolis) -- It has long been known that the outcome of an infection with the hepatitis C virus (HCV) can vary greatly among individuals. A report in the Dec. 18 issue of the journal The Lancet indicates that a patient's genetic factors may explain much of this variability.
"Infection with HCV can lead to anything from a self-limiting [mild and noncontagious] infection to cirrhosis, or scarring of the liver, to cancer," says lead author Mark Thursz, MRCP, from the Imperial College School of Medicine in London. "In some patients, the rate of progression is much faster than average, whereas in others, the rate of progression is negligible. What determines the outcome of HCV infection is not clear."
Hepatitis C is a virus that can cause liver disease and liver cancer. It is transmitted via blood, either from blood transfusions or IV drug use. It can also be transmitted from sexual contact. Initially it may cause a mild illness, but then resides in the body without symptoms. In at least 20% of cases, the HCV will reactivate and eventually cause a liver disease called cirrhosis. There are treatment options for HCV, many experimental, but there is no known medication that kills the virus.
Using patients recruited from eight large hospitals across Europe, the researchers looked at the distribution of a set of certain genes in patients with a self-limiting infection that went away on its own and a matched set of patients with a persistent infection. They also studied those with mild and severe injury to the liver and those patients who responded to treatment with interferon and those who did not.
Those with the self-limiting type of infection were more likely to have two specific genes. Two other genes were associated with persistent infections. These results were confirmed in a second-stage study. No significant associations were found between the presence of certain genes and injury or response to interferon.
"In the short term, this research has no direct relevance to the patient," says Thursz in an interview with WebMD. "However, in the future, identification of genetic factors which influence the outcome of hepatitis C virus infection will be used to identify patients at most risk of developing severe liver disease, identifying patients with a good chance of responding to treatment, and identifying disease pathways as targets for therapeutic intervention."