Science

Morphine inhibits interferon expression and enhances HCV replication

Last Updated: 2007-09-13 13:58:10 -0400 (Reuters Health)

By David Douglas

NEW YORK (Reuters Health) - Morphine appears to facilitate the persistence of hepatitis C virus (HCV) in human hepatocytes, US and Chinese researchers report in the September 1st issue of the Journal of Infectious Diseases. This may help explain the high prevalence of the disease in heroin users.

"Although injection heroin use contributes significantly to HCV transmission," senior investigator Dr. Wen-Zhe Ho told Reuters Health, "it remains unknown why the majority of heroin abusers are highly susceptible to HCV infection and unable to eliminate the infection."

Dr. Ho of the University of Pennsylvania School of Medicine, Philadelphia and colleagues used an in vitro cell model to investigate the influence of morphine on intrahepatic interferon-alpha expression.

This system, continued Dr. Ho, "provides direct evidence that morphine has the ability to inhibit interferon-alpha-mediated innate immunity against HCV infection in the liver cells, thus promoting HCV replication."

Moreover, morphine also compromised the anti-HCV effect of recombinant interferon-alpha, suggesting that immunosuppression by opiates may contribute to the development of chronic HCV disease, say the investigators.

"Future clinical studies," Dr. Ho concluded, "are needed to determine heroin-mediated immunosuppressive effects on HCV infection and interferon-alpha based therapy."

J Infect Dis 2007;196:719-730.