hepatitis B immune globulin (HBIg) for Chronic Hepatitis B

Background: Hepatitis B is a viral infection of the liver. When the immune system tries to clear hepatitis B, it damages the liver. Eventually, the immune system gets exhausted fighting the virus. Researchers want to see if giving large doses of an antibody (HBIg) with the drug peginterferon will boost the immune system in people with this disease. Objectives: To observe the effect of large doses of antibody against the hepatitis B surface antigen on the immune response to the virus. To see if removing hepatitis B surface antigen from the blood enhances the action of peginterferon. Eligibility: Adults ages 18 and older with hepatitis B Design: Participants will be screened twice with a medical history, physical exam, and blood and urine tests. Participants will be randomly put in one of two groups. All participants will get peginterferon for 24 weeks. One group will first get HBIg for 12 weeks. Participants in the combination group will have a 4-day clinic stay. They will have: Repeats of screening tests Eye exam Liver ultrasound The first dose of HBIg by IV over 2 hours These participants will get HBIg at the clinic up to 8 times over 12 weeks then start the peginterferon. All participants will get peginterferon for 24 weeks. They will get it by injection under the skin once a week. They may do this themselves. They will keep a drug diary. They will have 5 visits to assess response and monitoring for safety.. After stopping the study drug, participants will have 4 follow-up visits over 36 weeks. They will repeat screening tests and have 1 liver ultrasound.