HOW DOES HEPATITIS B VIRUS CAUSE HEPATITIS?
HBV is a hepatotrophic virus, meaning the virus replicates only within the liver. The virus gains access to the liver through blood. Once in the liver, HBV multiples and new viruses are exported from the liver cells back into the blood circulation. The immune system mounts an attack on the virus replicating in the liver and tries to eliminate the virus. This immune response results in inflammation and liver cell injury, which is termed “hepatitis.” If the immune response against HBV is robust and successful in eliminating the liver cells infected with virus, the person will recover from the infection. This is resolved acute HBV infection. The antibodies made by the individual’s immune system will protect them against future infection with HBV. After recovery from the acute infection, the liver returns to normal (hepatitis resolves) and there are no residual liver effects. In some individuals infected with HBV, however, the immune response is not successful in eliminating the virus. In
