Hepatitis B immunity in the pediatric liver transplant population.

Abstract

Hepatitis B virus (HBV) infection contributes significantly to vaccine-preventable disease related deaths, and insufficient HBV immunity may have unique implications for the pediatric liver transplant population. This article reviews the significance of HBV infection and the vaccination and screening measures needed to achieve adequate HBV immunity in these children. HBV non-immunity among transplant candidates is higher than expected, even after appropriate completion of the vaccine series. Annual measurement of quantifiable HBV surface antibody in this vulnerable group should guide administration of booster and/or re-vaccination, improving immunoprotection from this potentially deadly hepatotropic virus. The liver plays a vital role in immune regulation; it induces immune tolerance and competence and both clears antigens from the circulation and generates liver-primed memory cells through antigen presentation via hepatic scavenger cells. Lymphocyte populations are depleted in patients with liver disease. Immunity provided during early childhood against HBV infection is important to both pediatric liver transplant candidates and aging recipients. Appropriate vaccination and achievement of adequate immunity pre-transplant and post-transplant is critical. The field of pediatric transplantation is ripe for functional cellular and humoral immunity studies that examine factors which predict poor immune response to childhood vaccines, particularly HBV.