- Positive serology for hepatitis B (HB) defined as a positive test for hepatitis B surface antigen (HBsAg); in addition, if HBsAg is negative and hepatitis B core antibody (HBcAb) is positive, regardless of hepatitis B surface antibody (HBsAb) status, a HB deoxyribonucleic acid test will be performed and if HB DNA is positive the patient will be excluded; if a patient is HBsAg negative, HBcAb positive, and HBsAb positive, indicating past but not active infection, the patient will be included on the study