Abstract
AIM: To 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. METHODS: This 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. RESULTS: In 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. CONCLUSION: The 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.