慢性乙型肝炎患者拉米夫定治疗不同阶段HBV DNA多聚酶分析

Analysis of mutations at hepatitis B virus P gene in patients with chonic hepatitis during iamivudine therapy

目的分析拉米夫定治疗不同时期HBV DNA多聚酶区耐药突变的变化规律和主要耐药突变的分布情况。方法将接受拉米夫定治疗的98例患者根据治疗时间进行分组，采用PCR方法对其血清HBV多聚酶区进行扩增并对聚合酶链反应（PCR）产物进行直接测序。结果拉米夫定治疗后血清HBV DNA水平≥10^4copies／ml的患者中，治疗时间〈6个月6例，其中1例发生突变；6～12个月13例，其中7例发生突变；12～24个月19例，其中13例发生突变；24～36个月20例，其中19例发生突变，各组之间耐药突变发生率比较差异有统计学意义（P〈0．05）。耐药患者中有10种突变类型，其中以rtM204I突变最多见，为14例（35．0％），其次为rtL180M／M204V（17．5％）、rtL180M／M2041（12．5％）。结论对拉米夫定治疗6个月以上而没有达到病毒学完全应答的患者进行乙肝病毒基因耐药突变的检测，有助于及时准确的调整治疗方案。

Objective To analyze the regulation of lamivudine - mutations at hepatitis B virus （HBV） P gene in the different therapeutic periods and the distribution of major drug - resistant mutations at HBV P gene in patients resistant to lamivudine. Methods Serum sampes from 98 chronic hepatitis B patients with lamivudine therapy were collected, the HBV P gene RT region from them was amplified by PCR, and PCR products were directly sequenced. Results Among lamivudine -tredted patients with HBV DNA levels above 104 compies/ml, 1 mutation were found in the 6 patients who were treated with lamivudine less than 6 months, 7 found in the 13 patients treated from 6 to 12 months, 13 found in the 19 patients treated from 12 to 24 months, and 19 patients found in the 20 patients treated from 24 to 36 months, respectively. The incidences of mutations were significantly different in each group （ P 〈 0.05）. There were 10 forms of resistant mutation in the 40 lamivudine refractorypatients. The major were rtM204I （35.0%）, rtL180M/M204V （ 17. 5% ）. Conclusions It would be helpful to adjust the therapeutic regimen by testing mutations at hepatitis B virus P gene in patients who receive lamivudine therapy more than 6 months without complete virologic response.