Korean J Transplant.  2021 Oct;35(Supple 1):S141. 10.4285/ATW2021.OP-1158.

Long term protective level of hepatitis B antibody after revaccination in liver transplanted children: an open-label randomized control trial study

• Sintusek P
• Poovorawan Y
• Buranapraditkun S
• Wanawongsawad P
• Intrarakamhang Al

• KMID: 2521334
• DOI: http://doi.org/10.4285/ATW2021.OP-1158

Abstract

Background
High prevalence of hepatitis B (HB)-antibody loss after liver transplantation (LT) was documented and reimmunization is merit. This study aims to evaluate the long-term protective level of HB surface antibody (anti-HBs) after HB revaccination in liver transplanted children.
Methods
Liver-transplanted children with previously immunization but anti-HBs after LT ≤100 mIU/mL were recruited and ran-domized to reimmunization with standard-3-dose (SD) and double-3-dose (DD) HB vaccine intramuscularly at 0-1-6 months. Participants with anti-HBs <100 mIU/mL after reimmunization was defined as antibody loss. Antibody loss rate was estimated using Kaplan-Meier method and the difference between antibody loss from SD and DD was compared using log-rank test. To assess the variable associated with antibody loss over time, multivariable Cox proportional hazard regression analysis was performed.
Results
From 2016 to 2020, 68 children were recruited. The rate of anti-HBs ≥100 mIU/mL after complete vaccination was 87.1% and 80% in SD and DD. After the median follow-up period of 2.21 years (1.34, 2.96) from enrollment, geometric mean titer of anti-HBS was 199.32 mIU/mL (101.37–391.93) and 129.80 mIU/mL (60.59–278.08) in SD and DD (P=0.419). There were 64.5% and 56.7% of participants with anti-HBs >100 mIU/mL in SD and DD (P=0.530). The median for antibody loss over time were 3.01 (95% confidence interval [CI], 2.865–3.155) and 2.69 (95% CI, 2.341–3.049) years for SD and DD. There was no significant antibody loss over time between both groups (P=0.156). On the univariate analysis, low anti-HBs level at the enrollment was the only factor associated with increased risk of antibody loss over time (median anti-HBs of 2.2 mIU/mL; hazard ratio, 3.403; 1.631–7.099; P<0.001).
Conclusions
SD and DD for HB reimmunization were highly effective to maintain the protective level of anti-HBs in liver-transplanted children after long-term follow-up. Moreover, early HB reimmunization should be scheduled for liver-transplanted children at the time that anti-HBs level is not too low.