A key enzyme may explain how hepatitis C infection causes fatty liver - a buildup of excess fat in the liver, which can lead to life-threatening diseases such as cirrhosis and liver cancer, report University of Pittsburgh Graduate School of Public Health and School of Medicine researchers.
The study, published in the July 9 online issue of Hepatology, shows that an enzyme known to play a major role in lipid production, fatty acid synthase (FAS), was highly elevated in human liver cells exposed to the hepatitis C virus. While preliminary, the research suggests that testing for elevated levels of FAS could help determine which patients with hepatitis C virus may go on to develop more serious, long-lasting health consequences brought on by fatty liver.
Nearly 200 million people worldwide are infected by hepatitis C, including 4 million Americans. Seventy percent of people with hepatitis C develop chronic liver disease, and the infection is the leading reason for liver transplantation in the United States.
Unlike hepatitis A and B, there is no vaccine to prevent hepatitis C infection. Since hepatitis C typically has no symptoms, many people do not know they have the infection until they develop signs of liver failure or fatty liver, sometimes decades after infection. The virus replicates and mutates quickly, helping it to evade discovery and attack by the immune system and allowing it to slowly wreak damage on the liver.
"Our study has provided new insight into how hepatitis C causes fatty liver. This has important implications for future studies and efforts to understand how the virus causes an increase in fatty acid levels that can lead to serious liver conditions," said Tianyi Wang, Ph.D., assistant professor, Department of Infectious Diseases and Microbiology, University of Pittsburgh Graduate School of Public Health, and the study's lead author.