Undetected chronic hepatitis B virus infection of a vaccinated dialysis patient after liver transplantation.

Organ recipients are at risk of chronic hepatitis B infection when organs harbouring the virus are transplanted. The ‘resolved’ hepatitis B virus (HBV) infections of organ donors (those HBsAg negative, anti-HBc positive, anti-HBs positive) are frequently reactivated in immunosuppressed liver transplant recipients [1]. In some cases, vaccination before transplantation does not protect the recipient against the reactivation of HBV received via the graft; in fact, it may set the stage for the emergence of HBsAg escape mutants years after transplantation [2]. The replication of these mutants often remains undetected, because of any one of the following: the clinical course in the majority of infected and immunosuppressed patients is silent, antibody response may be delayed, only a few commercially available HBsAg assays are able to detect vaccinationand immunoglobulin-induced variants [3] and techniques to detect nucleic acid are not routinely used for HBV screening. Therefore, since renal replacement therapy is frequently needed in the management of liver transplantation, the potential exists to spread mutated HBV strains in the dialysis patient community—unless the high risk population of liver transplant recipients is screened with a nucleic acid technique (and due care is exercised in dialysis settings to prevent cross infection). We report the case of a dialysis patient who received a liver graft and became infected with an HBV strain bearing a novel mutation from cysteine to tryptophane (sC137W) in the adeterminant of the surface antigen at the amino acid position 137. This mutant virus escapes vaccination-induced immunity and is not detected by a routine HBsAg screening test. Our patient never presented clinical signs of hepatitis, and her HBV infection was only diagnosed 46 months after transplantation.