摘要
Abstract
[Objective] To research the outcome of one-year lamivudine therapy and the characters of HBV DNA polymerase gene mutations. [Methods] First extraction of HBV DNA from serum samples, then hemi-nested PCR, purification, sequencing reaction, precipitation and automatic sequencing. Summarize the outcome of lamivudine therapy and observe the time of YMDD mutation development, then analysis the influence factors of outcome by SAS software. Analysis the difference of amino acid of part P gene of HBV DNA, and draw the classification of mutation by CLUSTAL V method of DNA STAR software. Analysis the difference of protein secondary structure of HBV DNA P gene encoded before and after mutation by DNAclub and DNAsis software. [Results] There were not different in improving ALT normalization in four individual groups. After 12 months of therapy, the rate of HBeAg loss increased linearly with ALT level of baseline increasing, the rate was 72.41%; but the rate of HBeAg seroconversion decreased linearly with ALT level of baseline increasing, the rate was 13.79%. Two YMDD mutations had been detected from serum specimens of 12 months after therapy. One L528M single mutation was detected in control group.Two YVDD mutations were accompanied with L528M mutation. YMDD faced to 70-73AA, L528M faced to 47AA.The secondary structure of 47AA and 70-73AA protein was the turn when no mutation. After developing mutation,the turn of 70-73AA changed to the sheet, but the turn of 47AA did not change. [Conclusion] One-year lamivudine therapy can inhibit HBV DNA replication in patients with chronic hepatitis B, and improve ALT normalization.And the rate of HBeAg loss was 72.41%, the rate of HBeAg seroconversion was 13.79%. The ALT level of pretherapy was not enough to predict HBeAg seroconversion alone. YMDD mutations induced by lamivudine therapy usually develop after 6 months, and the YMDD mutant rate in patients with lamivudine therapy was 6.06% one-year.YVDD mutantion usually accompanied with L528M, L528M can exist in vivo alone, and L528M mutation can develop in asymptomatic carriers who did not accept antiviral therapy. Protein secondary structure of HBV DNA P gene encoded changed after P gene mutation, and the turn changed to the sheet. L528M mutation did not affect protein secondary structure.关键词
慢性乙型肝炎/拉米夫定/YMDD变异/蛋白质/二级结构Key words
chronic hepatitis B/lamivudine/YMDD mutation/protein/secondary structure分类
医药卫生
