- Active hepatitis B virus (HBV) or hepatitis C virus infection that requires treatment or at risk for HBV reactivation. At risk for HBV reactivation is defined as hepatitis B surface antigen positive or anti-hepatitis B core antibody positive. Previous test results obtained as part of standard of care before allo-HSCT that confirm a patient is immune and not at risk for reactivation (ie, hepatitis B surface antigen negative, surface antibody positive) may be used for purposes of eligibility.