Two-year assessment of entecavir resistance in Lamivudine-refractory hepatitis B virus patients reveals different clinical outcomes depending on the resistance substitutions present.
PMID: 17178796
2007
Antimicrobial agents and chemotherapy
Abstract: Prior studies showed that virologic rebound due to ETV resistance (ETVr) required preexisting LVDr HBV reverse transcriptase substitutions M204V and L180M plus additional changes at T184, S202, or M250.
"Molecular analysis of hepatitis B virus ""a"" determinant in asymptomatic and symptomatic Mexican carriers."
Discussion: The main mutations associated with LMV resistance are located at the RT gene in the 204 position (rtM204I/V), which is in the catalytic YMDD motif.
Discussion: Thus for mutations associated with LMV resistance, the rtM204V change is associated with a I195M change in the S gene (sI195M), while the rtM204I change is associated with three possible changes in the S gene, sW196S, sW196L,
Hepatitis B virus genotypes and lamivudine resistance mutations in HIV/hepatitis B virus-coinfected patients.
PMID: 17224847
2007
Journal of acquired immune deficiency syndromes (1999)
Abstract: The dual L180M + M204V/I mutant was the predominant resistance pattern, although a triple rt173V + 180M + 204V, which acts as a vaccine escape mutant, was found in 1 individual.
Stepwise process for the development of entecavir resistance in a chronic hepatitis B virus infected patient.
Abstract: Although the rtL180M+S202G+M204V variant, that prevailed at the end of entecavir therapy, did not show the highest viral genome replication capacity, it conferred one of the strongest resistance levels to entecavir.
Abstract: RESULTS: A mixture of lamivudine-resistant HBV strains coexisted following viral breakthrough to lamivudine, all harboring the rtM204V mutation.
Abstract: The rtV173L+L180M+M204V dominant mutant displayed strong lamivudine-resistance and the highest replication capacity.
Abstract: Three years later, the viral load rose again, and a complex mixture of entecavir-resistant strains, all harboring
The L80I substitution in the reverse transcriptase domain of the hepatitis B virus polymerase is associated with lamivudine resistance and enhanced viral replication in vitro.
PMID: 17438047
2007
Antimicrobial agents and chemotherapy
Abstract: Collectively, these results suggest that coselection of rtL80V/I and rtM204I/V occurs because the former compensates for the loss of replication efficiency associated with the acquisition of LMV resistance, particularly in the case of rtM204I.
Abstract: Coselection of rtL80V/I occurred in 46% of isolates in which LMV resistance was attributable to rtM204I but only 9% of those in which resistance was attributable to rtM204V.
Abstract: Mutations that result in the replacement of the methionine at position 204 of the deoxynucleoside triphosph
Hepatitis B virus genotype distribution and its lamivudine-resistant mutants in HIV-coinfected patients with chronic and occult hepatitis B.
PMID: 17506609
2007
AIDS research and human retroviruses
Abstract: These viral strains showed a methionine-to-valine substitution at codon 204 (rtM204V) in association with an upstream B-domain change at rtL180M.
Emergence of hepatitis B virus quasispecies with lower susceptibility to nucleos(t)ide analogues during lamivudine treatment.
PMID: 17567633
2007
The Journal of antimicrobial chemotherapy
Abstract: rtA181S without rtM204I/V was found in one patient.
Abstract: All but three patients had baseline rtM204I/V substitutions associated with rtL180M in 23, rtL80I/V in 14, rtV173L in 4, rtT184S in 3, rtQ215S in 2 and rtA181S in 2 cases.
Sequential treatment with lamivudine and alpha-interferon in anti-HBe-positive chronic hepatitis B patients: a pilot study.
Abstract: L180M/M204V mutations were identified during virological breakthrough.
In vitro drug susceptibility analysis of hepatitis B virus clinical quasispecies populations.
PMID: 17687019
2007
Journal of clinical microbiology
Abstract: HBV obtained from patients who had developed resistance to adefovir or lamivudine, as demonstrated by development of the rtA181V or rtL180M/M204V mutations in HBV polymerase, respectively, were tested.
Mutational patterns of hepatitis B virus genome and clinical outcomes after emergence of drug-resistant variants during lamivudine therapy: analyses of the polymerase gene and full-length sequences.
Abstract: Baseline characteristics, alanine aminotransferase (ALT) levels, and HBV DNA levels within 6 months after the emergence of YMDD variants did not differ significantly between patients with rtM204I alone and those with rtL180M/rtM204V.
Abstract: Between months 5 and 33 of therapy, mutations from methionine to isoleucine at rt204 (rtM204I) were detected in 18 patients, and mutations from methionine to valine at rt204 (rtM204V) were detected in 12.
HBV mutation literature information.
PMID: 
2007
Antimicrobial agents and chemotherapy
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