After allogeneic peripheral blood stem cell transplantation (PBSCT), children are at high risk of hepatitis B virus (HBV) infection because of the potential loss of HBV immunity. The factors which can affect it are not fully understand. This study aimed to assess the probability of hepatitis B surface antibody (HBsAb) disappearance after PBSCT and to evaluate the impact of donor and recipient immunity on HBsAb disappearance. A total of 110 patients who underwent PBSCT between January 2016 and December 2018 and their paired donors were retrospectively enrolled in this study. Before transplantation, 87 (79.1%) patients were HBsAb seropositive, and 23 (20.9%) were HBsAb seronegative. Fifty-five (63.2%) patients with protective HBsAb titers before PBSCT lost their HBV immunity within one year after transplantation. Univariate analysis showed that the low recipient pretransplant HBsAb titer, antithymocyte globulin (ATG) administration, corticosteroid administration and graft-versus-host disease (GVHD) were significant risk factors for HBsAb disappearance (P<0.05). Multivariate analysis showed that only recipient pretransplant HBsAb titers lower than 207.5 IU/L (P=0.022, hazard ratio (HR): 1.925, 95% confidence interval (CI): 1.101-3.367) and the presence of GVHD (P=0.033, HR=1.921, 95% CI: 1.056-3.495) were risk factors for HBsAb disappearance one year after HSCT. In conclusion, most recipients lost previously acquired immunity to HBV after PBSCT. A high titer of HBsAb in the recipient before transplantation had a protective effect against posttransplant HBsAb disappearance, but the presence of donor immunity did not significantly influence the maintenance of recipient immunity to HBV.

Approximately 20–40% of pediatric patients with anaplastic large-cell lymphoma (ALCL) develop recurrent disease. Here, we report a pilot experience using single-drug weekly vinorelbine (25 mg/m2/wk) as a salvage re-induction regimen in 4 consecutive pediatric patients with relapsed ALCL. All 4 patients achieved complete remission after 2 cycles of weekly vinorelbine and were disease-free alive at last evaluation. The main toxicity was hematologic. Only one week of vinorelbine administration was withheld for a grade 4 neutropenia in one patient. The results suggest that weekly vinorelbine has good efficacy and safety in the treatment of relapsed pediatric ALCL.