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Basic Characteristics of Mutations
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Mutation Site
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M204I |
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Mutation Site Sentence
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Three main patterns of Pol mutations were identified: rtM204I (single; n = 5), rtL180M + rtM204V/I (dual; n = 25), and rtV173L + rtL180M + rtM204V (triple; n = 9). |
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Mutation Level
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Amino acid level |
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Mutation Type
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Nonsynonymous substitution |
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Gene/Protein/Region
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RT |
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Standardized Encoding Gene
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P
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Genotype/Subtype
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- |
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Viral Reference
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-
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Functional Impact and Mechanisms
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Disease
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HBV-HIV Coinfection
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Immune
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- |
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Target Gene
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-
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Clinical and Epidemiological Correlations
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Clinical Information
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Y |
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Treatment
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Lamivudine(LAM) |
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Location
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- |
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Literature Information
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PMID
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16549970
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Title
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Characteristics of drug resistant HBV in an international collaborative study of HIV-HBV-infected individuals on extended lamivudine therapy
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Author
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Matthews GV,Bartholomeusz A,Locarnini S,Ayres A,Sasaduesz J,Seaberg E,Cooper DA,Lewin S,Dore GJ,Thio CL
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Journal
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AIDS (London, England)
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Journal Info
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2006 Apr 4;20(6):863-70
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Abstract
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BACKGROUND: Little is known about the prevalence and pattern of hepatitis B virus (HBV) mutations in HIV/HBV co-infected individuals on long-term lamivudine (3TC) therapy. METHODS: HBV polymerase/envelope/basal core promoter/pre-core sequences from 81 HIV-HBV co-infected persons who received at least 6 months 3TC were compared to HBV reference sequences. Host and viral characteristics associated with HBV mutations were determined. RESULTS: HBV viraemia was detected in 53 persons (65%) and was associated with lower CD4 cell count nadir and higher HIV RNA at the time of testing but not with 3TC duration. Known 3TC-resistant mutations occurred in 50% and 94% of viremic patients with < 2 years and > 4 years 3TC, respectively. The CD4 cell count at testing was significantly higher in those with 3TC-resistant mutations. The triple polymerase mutant (rtL173V, rtL180M, rtM204V), which behaves as a vaccine escape mutant in vitro, occurred in 17% of viraemic patients. Polymerase mutations that may confer resistance to other anti-HBV agents were also detected. CONCLUSIONS: In HIV-HBV co-infected patients, greater immunocompromise is associated with continued HBV viraemia while on 3TC, and development of 3TC-resistant mutations are inevitable with prolonged 3TC use. These mutant viruses may limit future therapeutic options due to cross-resistance or may produce HBV vaccine escape mutants. Thus, timing and selection of antiretroviral therapy is critical in this population.
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Sequence Data
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-
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