the incidence of drug- resistant mutants in patients with chronic hbv infection after lamivudine treatment

conclusions this study showed that the presence of mutation at codons rtl80v, rtl180m and rtm204v in a, b and c domains is associated with higher viral load and resistance to lamivudine (3tc) respectively. results about 6% (3 of 50) of samples were hbeag positive and 94% (47 of 50) of patients were hbeag negative by elisa method. the patients' alt level was between 16 and 95 iu/l with the mean of 37.58 iu/l. also, 48% (24 of 50) of samples had < 104 iu/ml viral load, 52% (26 of 50) of them had > 104 iu/ml viral load. about 10% (5 of 50) of samples was treated with lamivudine with specific substitution of amino acid located at codons 80, 180 and 204. in addition, phylogenetic tree showed that genotype d of hbv was dominant among iranian hbv infected patients objectives the aim of this study was to investigate rtl180m and rtm204v mutations in polymerase gene of hbv in infected patients after lamivudine therapy. patients and methods fifty sera samples collected from patients who referred to blood transfusion center in tehran were studied. the samples were divided into two groups; treated and untreated based on antiviral treatment status. from 50 patients, 34% were males and 66% were females, aged between 18 and 80 years.rnall of samples were tested for anti hepatitis b e antibody (anti-hbe), hepatitis b e antigen (hbeag), hepatitis b surface antigen (hbsag) and hepatitis b core antibody (anti-hbc) by enzyme-linked immunosorbent assay (elisa) method. the alt levels were measured using a commercial kit. then hbv-dna was extracted from serum samples using a commercial kit and a fragment of the p gene was amplified by nested pcr. also, hbv viral load was detected by real-time pcr. hbv genotypes and polymerase gene mutations were determined by direct sequencing of the polymerase gene of hbv. phylogenetic tree was constructed using neighbor-joining (nj) method. background hepatitis b virus (hbv) is replicated through reverse transcription of polymerase gene. lamivudine can postpone the clinical progression in hepatitis b infected patients, but the long-term monotherapy causes the emerge of ymdd (tyrosine-methionine-aspartate-aspartate), llaq (leucine–leucine–alanine–glutamine) motifs and increases the alanine aminotransferase (alt) and hbv dna levels.