We wished to undertake molecular characterization of the reverse transcriptase (RT) gene and overlapping surface (S) gene in lamivudine-treated patients with chronic infection with the hepatitis B virus (HBV). Sequencing analyses of the HBV RT/S gene of isolates from 25 chronic hepatitis B (CHB) patients with the YMDD mutation and 30 treatment-naïve CHB patients were undertaken. In patients with the YMDD mutation, rtM2041 was the major type of mutation (20/25, 80%). rtL80I was present in most of the patients with rtM204I (14/20, 70%). rtL180M coexisted with rtM204V (5/5, 100%). Patients with the YMDD mutation had a significantly higher prevalence of mutation of the RT gene than treatment-naïve CHB patients (P < 0.05). Classical primary resistance and secondary/compensatory mutations were detected at only five sites (rtL80, rtV173, rtL180, rtM204, rtM250) in CHB patients with the YMDD mutation. The frequency of nucleos(t)ide analog resistance (NAr) mutation within the RT gene in patients with the YMDD mutation was significantly higher than that in treatment-naïve patients (P < 0.05). Amino-acid mutations within the RT gene were also associated with other types of NAr in patients with the YMDD mutation. The rate of amino-acid variants within the S gene region was significantly higher in patients with the YMDD mutation than that in treatment-naïve patients (P < 0.05). sM133L and sG145R variants were also present in patients with the YMDD mutation. These observations suggest that CHB patients with the YMDD mutation also have NAr mutations related to other NA drugs, which might lead to cross-resistance in CHB patients. Variants present in the S gene region could cause changes in the antigenicity of HBsAg, which could result in a false-negative diagnosis of HBsAg and immune in escape of the HBV.
Adolescent ; Adult ; Antigens, Surface ; genetics ; Antigens, Viral ; genetics ; DNA Mutational Analysis ; Female ; Genetic Variation ; Hepatitis B, Chronic ; drug therapy ; genetics ; Humans ; Lamivudine ; pharmacology ; therapeutic use ; Male ; Middle Aged ; RNA-Directed DNA Polymerase ; genetics ; Young Adult

Objective To analyze the variations of surface(S) region,basic core promoter (BCP) and precore (preC) regions in genomes of hepatitis B virus (HBV) from patients with coexistence of hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (anti-HBs).Methods S region,BCP and preC regions in genomes of HBV were amplified and sequenced in 62 HBV-infected patients including 27 HBsAg-positive/anti-HBs-positive patients (double positive group) and 35 HBsAg-positive/ anti-HBs-negative patients (single positive group).The sequencing results and amino acid variants in these regions were analyzed.Difference of means between groups was compared by t test.Sample rate and variation rate were compared by chi-square test.Results One hundred and fifty-six amino acids mutations within the S region were detected in 27 patients of double positive group and 100 mutations in 35 patients of single positive group.The mutation rate in double positive group was significantly higher than those in single positive (2.56％ vs 1.26％,x2 =32.07,P＜0.05).The amino acid variants in double positive group were much higher than those in single positive group within major hydrophilic region (MHR),especially in the first loop area of a-determinant in S region (4.76 ％ vs 1.02 ％,x2 =11.58,P＜0.05).The mutation rate of A1762T/G1764A in BCP in double positive group was significantly higher than those in single positive group (59.3％ vs 28.6％,x2 =5.895,P＜0.05).The mutation rate of A1846T in preC region was higher in double positive group than those in single positive group (40.7％ vs 17.1％,x2-4.265,P＜0.05).The mutation rate of A1762T/G1764A+G1896A in double positive group was also higher than that in single positive group (37.0％ vs 14.3％,x2 =4.302,P＜0.05).Conclusions The mutation rates of S region,especially in the first loop area within a-determinant,BCP and preC regions which are related with hepatocellular carcinoma development in HBsAg and anti-HBs double positive group are higher than those in HBsAg single positive group in chronic HBV infected patients.