Approximately 350 million people worldwide (5% of the world’s population) are infected with the hepatitis B virus (HBV), characterized by presence of the HBV surface antigen.1 Carriers of HBV will harbor undetectable or very low HBV DNA levels with normal alanine aminotransferase (ALT) levels, whereas those with active HBV will harbor higher HBV DNA levels, often with elevated ALT levels. Others will have cleared the virus, characterized by absence of hepatitis B surface antigen or detectable levels of HBV DNA, and by the presence of the HBV core antibody, with or without hepatitis B surface antibodies.
Abramson JS, Chung RT. Optimal Antiviral Prophylaxis Against Hepatitis B Reactivation in Patients Receiving Rituximab-Based Chemotherapy for Lymphoma. JAMA. 2014;312(23):2505-2507. doi:10.1001/jama.2014.16095