Relevance of Hepatitis B Virus Genome Variability in Organ Transplantation

Hepatitis b virus (hbv) can cause acute and chronic hepatitis in humans, with the latter possibly leading to livercirrhosis and hepatocellular carcinoma. the clinical course of hbv infection is critically dependent on genetic andimmune features of the host as well as on virological factors. in situations of immune suppression, e.g. in patients afterorgan transplantation with chronic hbv infection, severe progression of liver disease can occur, due to direct effects ofimmunosuppressive regimens on hbv's hepatotoxicity or replication and due to the selection of hbv mutants. hbvvariants are commonly found in chronically infected patients because of the lack of proofreading capacity of the hbvreverse transcriptase. examples of relevant hbv mutations include precore or basal core promoter mutants withincreased replication capacity, escape mutants with alterations in the 'a-determinant' immune epitope, core genedeletions after renal transplantation, antiviral drug resistant strains and accumulation of complex hbv variants afterlong-term immune suppression. in this review, we present the virological background of hbv genetic variability, discussfrequent mutations observed in transplanted patients and address the effects of hbv genetic variability on the clinicaloutcome in solid organ transplant recipients.