Abstract |
Occult hepatitis B virus (HBV) infection is characterized by the presence of HBV DNA while the HBV surface antigen ( HBsAg) remains undetectable. The HBV genomes in five asymptomatic blood donors with occult HBV infection and low viremia (<10 to 1,000 HBV DNA copies/mL, genotype D) were studied. An unusually large number of amino acid mutations was present in the immunodominant a-determinant of HBsAg (respectively 3, 6, 7, 10, and 10 mutations). Comparison of the HBV genomes in two donors to a consensus HBV genotype D sequence showed a most prominent hotspot of genetic variation in HBV nucleotides 480-570, encoding the HBsAg a-determinant. The phylogenetic comparison of separate donor HBV genes to the HBV genes of 11 reference strains (genotypes A-H) showed the donor HBV surface genes to form an outgroup, while the HBV polymerase, core and X genes closely cluster with the HBV genotype D reference strain. Maybe the HBV strains in this study represent a natural end-stage of seemingly cleared HBV infection, in which HBV maintains a low level of possibly non-infectious replication, after sacrificing its immunologically offending surface antigen, thus avoiding final clearance by the immune system.
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Authors | H L Zaaijer, P Torres, A Ontañón, L González Ponte, M H G M Koppelman, P N Lelie, F J van Hemert, H J Boot |
Journal | Journal of medical virology
(J Med Virol)
Vol. 80
Issue 8
Pg. 1344-9
(Aug 2008)
ISSN: 1096-9071 [Electronic] United States |
PMID | 18551607
(Publication Type: Journal Article)
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Chemical References |
- DNA, Viral
- Hepatitis B Surface Antigens
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Topics |
- Adult
- Aged
- Amino Acid Sequence
- Blood Donors
- DNA, Viral
(blood)
- Female
- Hepatitis B
(blood, virology)
- Hepatitis B Surface Antigens
(blood, chemistry, genetics)
- Hepatitis B virus
(genetics, immunology)
- Humans
- Male
- Middle Aged
- Molecular Sequence Data
- Mutation
- Sequence Analysis, DNA
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