title: Clinical and virological characteristics of lamivudine resistance in chronic hepatitis B patients: a single center experience.
abstract: We have investigated the characteristics of lamivudine-resistant strains in patients with chronic hepatitis B in Guangdong, China, where the predominant genotypes are B and C. Two hundred forty-seven patients treated with lamivudine in Nanfang Hospital were followed-up. Patients with hepatitis B e antigen (HBeAg) positive and hepatitis B virus (HBV)-DNA levels over 7.5 x 10(6) copies/ml at baseline had a shorter time to the selection of YMDD mutant (P = 0.02 and 0.00, respectively). The detection of YMDD mutant precedes HBV-DNA breakthrough and alanine transaminase (ALT) flare in about 2 and 3 months, respectively. The ALT flare after the appearance of YMDD mutants was more evident in HBeAg positive patients than HBeAg negative patients (P = 0.02). After emergence of YMDD mutant, the HBV-DNA level was significantly higher in genotype C patients compared with genotype B patients (P = 0.02). No significant difference of YMDD mutant pattern was found between patients with genotype B and C. Four kinds of new mutants were found in over two patients including rtL80I, rtG172E, rtG174C, and rtG172E/rtG174C. In vitro transfection and real-time analysis showed that rtG172E, rtG174C, and rtG172E/rtG174C mutants had a decreased replication competence compared with wild type (33%, 27%, and 15% of the wild type HBV, respectively). Our result suggest that genotypic monitoring of YMDD mutant is important for the management of patients treated with lamivudine.
authors.affiliation: Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.forename: Zhanhui
authors.initials: Z
authors.lastname: Wang
authors.forename: Shiwu
authors.initials: S
authors.lastname: Ma
authors.forename: Guobing
authors.initials: G
authors.lastname: Zeng
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zhou
authors.forename: Kangxian
authors.initials: K
authors.lastname: Luo
authors.forename: Jinlin
authors.initials: J
authors.lastname: Hou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000410:Alanine Transaminase / Q000097:blood; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D002648:Child; D002681:China; D004279:DNA, Viral / Q000097:blood; D024882:Drug Resistance, Viral / Q000235:genetics*; D005260:Female; D005838:Genotype; D006513:Hepatitis B e Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D019694:Hepatitis B, Chronic / Q000503:physiopathology / Q000821:virology*; D006801:Humans; D019259:Lamivudine / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology*; D014779:Virus Replication / Q000235:genetics
chemical_list: D004279:DNA, Viral; D006513:Hepatitis B e Antigens; D018894:Reverse Transcriptase Inhibitors; D019259:Lamivudine; D000410:Alanine Transaminase