RESUMO
Objective To explore the use of lamivudine alone induced the poor response,especially the related factors of the occurrence of YMDD.Methods Retrospective analysis of 160 cases of the poor answering cases after lamivudine treatment,the baseline parameter values,the time appearing to the poor answering and the HBVDNA load in treatment were analyzed,to study their relationship with poor response.Results The lamivudine prolonged,the poor response to the probability gradually increase.The mutation rate in the 12nd month was 19.67％ and in the 36th month was 49.18％ ( P ＜ 0.05 ).Response to the many reasons,the YMDD mutation is the more common one.The relationship among HBVDNA load,ALT level on baseline and the rate of poor response emergence,the YMDD mutation rate was clear.By comparison in groups,the difference was significant (P＜0.05).Conclusion The lower baselins of ALT level,the higher of HBVDNA load,the greater probability of the poor response and the YMDD mutation.