Men infected with a combination of hepatitis B virus and HIV are 17 times more likely to die from liver disease than men infected with hepatitis B alone, according to a study.

"These results underscore the importance of prevention, treatment and comprehensive management of hepatitis B in people infected with HIV," says Chloe Thio, assistant professor of medicine in the Division of Infectious Diseases at Johns Hopkins and lead author of the study.

The low rate of liver disease-related deaths in those with hepatitis B alone is consistent with the 20 to 30 years typically needed for complications from hepatitis B to develop, explains Thio. However, because HIV and hepatitis B are transmitted in the same way, coinfection is common and up to 10 per cent of HIV-infected individuals also have ongoing hepatitis B infection, says Thio.

"Our results suggest that HIV increases the severity of hepatitis B infections, and that physicians may see an increase of hepatitis B-related liver disease in the 1 million people living with HIV in the United States," says Thio.

Thio and colleagues analyzed clinical data and blood and tissue samples collected from 1994 to 2000 from 5,293 men who participated in the Multicenter AIDS Cohort Study. The researchers compared death rates from liver disease in four patient groups: HIV-infected individuals, hepatitis B-infected individuals, individuals infected with both viruses, and virus-free individuals. They found that 326 men (6 percent) had hepatitis B, of whom 213 (65 percent) also had HIV. Of the 4,987 men without hepatitis B, 2,346 (47 percent) were infected with HIV. Liver disease-related death was highest among those with advanced HIV disease, as measured by CD4 cell count, and was twice as high after 1996, when highly effective HIV therapies were introduced.

"Determining possible adverse effects of long-term use of HIV therapies and assessing the possible interaction with hepatitis infections are central questions that our ongoing studies will address," says Alvaro Mu, professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health.

According to the World Health Organization, hepatitis B is the leading cause of chronic liver disease and liver cancer, and is the ninth leading cause of death worldwide.