Hepatitis A antibodies in liver transplant recipients: evidence for loss of immunity posttransplantation.

Liver transplant recipients frequently have chronic liver diseases and should be considered for vaccination against hepatitis A virus (HAV). However, persistence of protective antibodies after orthotopic liver transplantation (OLT) has not been shown in this population, which may have implications for future vaccine recommendations. We evaluated the prevalence and epidemiological significance of immunoglobulin G (IgG) antibody to HAV (anti-HAV) in a nonvaccinated population before OLT (immunity from previous exposure) and determined the persistence of IgG anti-HAV at 1 and 2 years after OLT. One hundred consecutive patients were identified who underwent OLT and had at least 2 years of follow-up post-OLT. They were not vaccinated against HAV infection at any time. Clinical data were summarized from medical records, and stored sera were tested for IgG anti-HAV before OLT and at 1 and 2 years after OLT by a commercially available enzyme immunoassay. Of 100 patients, 24 had IgG anti-HAV before OLT. No epidemiological differences were noted between those with or without detectable IgG anti-HAV before OLT. Among patients with detectable IgG anti-HAV before OLT, 4 of 22 patients (18%) and 7 of 24 patients (29%) became negative for IgG anti-HAV at 1 and 2 years post-OLT, respectively. None of the patients with undetectable IgG anti-HAV before OLT became positive at any time. Most of our patients with end-stage liver disease had no serological evidence for immunity against HAV. A significant proportion of patients with detectable protective antibodies before OLT lost their antibodies at 2 years after OLT.