Patients
Data from patients who underwent allogeneic PBSCT between January 2016 and December 2018 in Shanghai Children’s Medical Center and their paired donors were reviewed retrospectively. Informed consent was obtained from each patient or their family, following the principles of the Declaration of Helsinki. Inclusion criteria included age under 18 years, sustained remission of the underlying disease after PBSCT, a follow-up period of more than 12 months, a complete set of clinical and medical records, and no medical history of HBV infection. Exclusion criteria included the failure to achieve remission or death during the study period, HBV infection prior to transplantation and missing complete records regarding HBsAb. Basic information about the patients, paired donors and transplant-related complications was extracted by retrospective review of the electronic medical records.