title: Treatment of chronic hepatitis B patients with tyrosine-methionine-aspartate-aspartate mutations.
abstract: Lamivudine is an antiviral used for the treatment of chronic hepatitis B. Several studies have reported various mutations that are induced by lamivudine therapy. These mutations in the tyrosine-methionine-aspartate-aspartate (YMDD) motif are necessary and sufficient to confer high-level lamivudine resistance. During treatment with lamivudine, mutations develop in the YMDD motif of the hepatitis B virus (HBV) polymerase gene and lamivudine cannot prevent the replication of the mutant form. The virulence strain of developed mutation in the polymerase gene is lower than the original virus and they are susceptible to treatment with some other nucleoside analogs except lamivudine. Entecavir and tenofovir are potent HBV inhibitors and they can be confidently used as first line monotherapies. We read the article written by Tan et al that lamivudine therapy improved the clinical course in HBV patients with natural YMDD mutations. We think that lamivudine use for this patient group is not appropriate. These patients should use YMDD mutant form-effective drugs such as adefovir, tenofovir.
authors.affiliation: Aylin Calica Utku, Oguz Karabay, Department of Infectious Diseases and Clinical Microbiology, Sakarya University Training and Research Hospital, 54200 Sakarya, Turkey.
authors.forename: Aylin
authors.initials: A
authors.lastname: Calica Utku
authors.affiliation: Aylin Calica Utku, Oguz Karabay, Department of Infectious Diseases and Clinical Microbiology, Sakarya University Training and Research Hospital, 54200 Sakarya, Turkey.
authors.forename: Oguz
authors.initials: O
authors.lastname: Karabay
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics*; D000998:Antiviral Agents / Q000627:therapeutic use*; D005260:Female; D006515:Hepatitis B virus / Q000187:drug effects*; D019694:Hepatitis B, Chronic / Q000188:drug therapy*; D006801:Humans; D019259:Lamivudine / Q000627:therapeutic use*; D008297:Male; D009154:Mutation
chemical_list: D000998:Antiviral Agents; D019259:Lamivudine
keywords: Drug resistance; Hepatitis B; Lamivudine; Treatment; Tyrosine-methionine-aspartate-aspartate mutation
references.citation: J Hepatol. 2012 Jul;57(1):167-85
references.pmid: 22436845
references.citation: World J Gastroenterol. 2015 Feb 21;21(7):2089-95
references.pmid: 25717242