Long-term outcomes of active vaccination against de novo hepatitis B among pediatric recipients of living donor liver transplantations with anti-HBc (+) grafts: a retrospective case-control study.

Background: Active vaccination has been utilized to prevent de novo hepatitis B virus infection (DNHB) in anti-HBc (+) grafts after liver transplantation. However, the long-term efficacy of active vaccination and graft/patient outcomes of anti-HBc (+) grafts have yet to be comprehensively investigated.

Materials And Methods: Among 204 pediatric patients enrolled in the study, 82 recipients received anti-HBc (+) grafts. For DNHB prevention, active vaccination was repeatedly administered prior to transplant. Antiviral therapy was given to patients with pretransplant anti-HBs <1000 IU/ml (nonrobust response) for 2 years and discontinued when post-transplant patients achieved anti-HBs >1000 IU/ml, while antiviral therapy was not given in patients with an anti-HBs titer over 1000 IU/ml. The primary outcome was to investigate the long-term efficacy of active vaccination, while the secondary outcomes included the graft and patient survival rates.

Results: Among the 82 anti-HBc (+) transplant patients, 68% of recipients achieved a robust immune response, thus not requiring antiviral therapy. Two patients (2.4%) developed DNHB infection, one of which was due to an escape mutant. With a median follow-up of 150 months, the overall 10-year patient and graft survival rates were significantly worse in recipients of anti-HBc (+) grafts than those of anti-HBc (-) grafts (85.2 vs 93.4%, P =0.026; 85.1 vs 93.4%, P =0.034, respectively). Additionally, the 10-year patient and graft outcomes of the anti-HBc (+) graft recipients were significantly worse than those of the anti-HBc (-) graft recipients after excluding early mortality and nongraft mortality values (90.8 vs 96.6%, P =0.036; 93.0 vs 98.3%, P =0.011, respectively).

Conclusion: Our long-term follow-up study demonstrates that active vaccination is a simple, cost-effective strategy against DNHB infection in anti-HBc (+) graft patients, whereby the need for life-long antiviral therapy is removed. Notably, both the anti-HBc (+) grafts and patients exhibited inferior long-term survival rates, although the exact mechanisms remain unclear.