AIMTo assess the seroprevalence of hepatitis B virus (HBV) immunity among previously vaccinated pediatric liver transplant recipients and present a case report of de novo hepatitis B infection after liver transplantation.METHODSThis study focused on children with chronic liver diseases who received primary hepatitis B immunization and had a complete dataset of anti-HBs before and after liver transplantation between May 2001 and June 2017. Medical records were retrospectively reviewed for potential factors relating to HBV immunity loss.RESULTSIn total, 50 children were recruited. The mean time from liver transplantation to anti-HBs testing was 2.53 ± 2.11 years. The mean anti-HBs levels before and after liver transplantation were 584.41 ± 415.45 and 58.56 ± 6.40 IU/L, respectively. The rate of non-immunity (anti-HBs < 10 IU/L) in the participants was 46% (n = 26) at one year, 57% (n = 7) at two years and 82% (n = 17) at > three years following liver transplantation. The potential factors relating to HBV immunity loss after liver transplantation were identified as anti-HBs (P = 0.002), serum albumin (P = 0.04), total bilirubin (P = 0.001) and direct bilirubin (P = 0.003) before liver transplantation. A five-year-old boy with biliary cirrhosis received 4 doses of HBV vaccine with an anti-HBs titer of > 1000 IU/L and underwent liver transplantation; his anti-HBc-negative father was the donor. After liver transplantation, the boy had stenosis of the hepatic artery up to the inferior vena cava anastomosis and underwent venoplasty three times. He also received subcutaneous injections of enoxaparin for 5 mo and 20 transfusions of blood components. Three years and ten months after the liver transplantation, transaminitis was detected with positive tests for HBsAg, HBeAg, and anti-HBc (2169.61, 1706 and 8.45, respectively; cutoff value: < 1.00) and an HBV viral load of 33212320 IU/mL.CONCLUSIONThe present study showed that loss of hepatitis B immunity after liver transplantation is unexpectedly common. In our case report, despite high levels of anti-HBs prior to transplantation, infection occurred at a time when, unfortunately, the child had lost immunity to hepatitis B after liver transplantation.

A high prevalence of hepatitis B (HepB) antibody loss after liver transplantation (LT) and de novo HepB infection (DNH) was documented, hence revaccination to prevent DNH is crucial. This study aimed to compare the safety and immunogenicity of two HepB vaccine regimens in liver-transplanted children. Liver-transplanted children who were previously immunised but showed HepB surface antibodies (anti-HBs) ≤ 100 mIU/mL were randomised to receive a standard three-dose (SD) and double three-dose (DD) vaccine intramuscularly in months 0–1–6. Anti-HBs and T-cell-specific response to the HepB antigen were assessed. A total of 61 children (54.1% male, aged 1.32 ± 1.02 years) completed the study without any serious adverse reaction. The seroprotective rate was 69.6% vs. 60% (p = 0.368) and 91.3% vs. 85% (p = 0.431) in SD and DD after the first and third 3-dose vaccinations, respectively. The geometric mean titre (95% confidence interval) of anti-HBs in SD and DD were 443.33 (200.75–979.07) vs. 446.17 (155.58–1279.50) mIU/mL, respectively, at completion. Numbers of interferon-γ-secreting cells were higher in hyporesponders/responders than in nonresponders (p = 0.003). The significant factors for the immunologic response to HepB vaccination were anti-HB levels prevaccination, tacrolimus trough levels, and time from LT to revaccination. SD and DD had comparative immunogenicity and were safe for liver-transplanted children who were previously immunised.

BACKGROUND Liver transplantation (LT) has become an acceptable curative method for children with several liver diseases, especially irreversible acute liver failure and chronic liver diseases. King Chulalongkorn Memorial Hospital is one of Thailand’s largest liver transplant centers and is responsible for many pediatric cases. AIM To report the experience with pediatric LT and evaluate outcomes of living-related vs deceased-donor grafts. METHODS This evaluation included children who underwent LT between August 2004 and November 2019. Data were retrospectively reviewed, including demographics, diagnoses, laboratory values of donors and recipients, the pediatric end-stage liver disease (PELD) or model for end-stage liver disease (MELD) score, graft source, wait time, perioperative course, postoperative complications, and survival rates. Continuous data were reported using the median and interquartile range. The Mann–Whitney U- test was used to compare the wait time between the living-related and deceased-donor groups. The chi-square or Fisher's exact test were used to compare the frequencies of between-group complications. Survival rates were calculated using the Kaplan–Meier method. RESULTS Ninety-four operated pediatric liver transplant patients were identified (54% were females). The median age at transplantation was 1.2 (0.8-3.8) years. The median PELD and MELD scores were 20 (13-26.8) and 19.5 (15.8-26.3), respectively. Most grafts (81.9%) were obtained from living-related donors. The median wait time for the living donors was significantly shorter compared with the deceased donors at 1.6 (0.3-3.1) mo vs 11.2 (2.1-33.3) mo ( P = 0.01). Most patients were diagnosed with biliary atresia (74.5%), and infection was the most common complication within 30 d post-transplantation (14.9%). Without a desensitization protocol, 9% of transplants were ABO-incompatible. Eight hepatitis B core antibodies (anti-HBc)-negative recipients received positive anti-HBc grafts without different observed complications. The overall survival rate was 93.6% and 90.3% at 1 and 5 years, respectively. No graft loss during follow-up was noted among survivors. CONCLUSION A significant number of pediatric LT cases were reported in Thailand. Based on relatively comparable outcomes, ABO-incompatible and HBc antibody-positive grafts may be considered in an organ shortage situation.

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 randomized 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.