Why Hepatitis B Hits Men Harder Than Women

Scientists in China are reporting discovery of unusual liver proteins, found only in males, that may help explain the long-standing mystery of why the hepatitis B virus (HBV) sexually discriminates -- hitting men harder than women.

Their study, "An altered pattern of liver apolipoprotein A-I is implicated in male chronic hepatitis B progression," has been published online in the Journal of Proteome Research.

Shuhan Sun, Fang Wang and colleagues note that chronic hepatitis B seems to progress and cause liver damage faster in men, with men the main victims of the virus's most serious complications -- cirrhosis and liver cancer. Men infected with HBV also are six times more likely than women to develop a chronic form of the disease. About 400 million people worldwide have chronic hepatitis B, including a form that is highly infectious and can be transmitted through blood, saliva and sexual contact.

In experiments with laboratory mice, the scientists found abnormal forms of apolipoprotein A-I (Apo A-I), a protein involved in fighting inflammation, in the livers of infected male mice but not infected females. They then identified abnormal forms of these Apo A-I proteins in blood of men infected with HBV, but not in women. In addition to explaining the gender differences, the proteins may provide important markers for tracking the progression of hepatitis B, the scientists suggest.