4. Active hepatitis B infection (defined as the presence of detectable HBV DNA, HBe antigen or HBs antigen). Subjects with serologic evidence of prior vaccination (HBsAg negative, anti-HBs antibody positive, anti-HBc antibody negative) are eligible. Patients who are HBsAg negative/HBsAb positive but HBcAb positive are eligible, provided HBV DNA is negative. NOTE - definitions for abbreviations: HBV - hepatitis B virus; DNA - deoxyribonucleic acid; HBe - hepatitis B e; anti-HBs - hepatitis B surface antibody; anti-HBc - hepatitis B core antibody; HBsAg - hepatitis B surface antigen; HBsAb - hepatitis B surface antibody; HBcAb - hepatitis B core antibody