拉米夫定治疗引起HBVYMDD变异的检测及临床意义

Detection and clinical significance of YMDD motif mutation during Lamivudine therapy for chronic hepatitis B

目的探讨拉米夫定治疗慢性乙型肝炎引起的HBVYMDD变异与HBVDNA病毒载量与血清谷丙转氨酶(ALT)之间的关系。方法140例拉米夫定治疗48￣96周的慢性乙型肝炎患者为研究对象。用荧光定量PCR法检测HBVDNA,基因序列分析检测HBVYMDD变异,全自动生化分析仪检测ALT水平。结果140例检测标本46例存在YMDD变异,变异率为32.86%,其中29例(20.71%)为rtM204V/rtL180M变异,16例(11.43%)为rtM204I变异,1例(0.72%)为rtM204I/rtL180M变异。HBVDNA>105拷贝/mL的发生率变异株组(40/46,86.96%)明显高于野生株组(6/94,6.38%)(χ2=90.889,P<0.01)。血清ALT水平变异株组(143.96±192.97)u/L明显高于野生株组(41.29±31.54)u/L(F=25.409,P<0.01)。结论慢性乙型肝炎患者应用拉米夫定48￣96周YMDD变异率为32.86%,变异类型以rtM204V/rtL180M为主,其次为rtM204I。变异时HBV-DNA病毒载量及ALT水平升高。

[Objective] To explore the relationship between YMDD motif mutation, hepatitis B viral loads and alanine aminotransferase （ALT） levels during Lamivudine therapy for chronic hepatitis B. [Methods] 140 chronic hepatitis B patients receiving 48-96 weeks Lamivudine therapy were studied. HBV DNA quantification was determined using fluorescent quantitative polymerase chain reaction （PCR）. YMDD mutation in the HBV DNA polymerase gene was determined using PCR and direct sequencing. ALT levels were measured using fully automatic biochemical analyzer. [Results] 46 （32.86%） out of 140 chronic hepatitis B patients had HBV YMDD （tyrosine-methionine-aspartate-aspartate） mutation. Among them, 29 patients （20.71%） had rtM204V＋rtL180M mutation, 16 patients （11.43%） had rtM204Ⅰ mutation and 1 patients （0.72%） had rtM204Ⅰ＋rtL180M mutation. Incidence of HBVDNA〉 10^5copies/ml of the mutant group （40/46, 86.96%） was significantly more than that of the wild-type group （6/94, 6.38%） （X^2=90.889, P 〈0.01）. Serum ALT level of the mutant group （143.96±192.97） U/L was significantly higher than that of the wild-type group （41.29±31.54） U/L （F=25.409, P 〈0.01）. [Conclusions] The YMDD mutation rate was 32.86% in chronic hepatitis B patients treated with Lamivudine for 48-96 weeks. The main mutation type was rtM204Ⅴ＋rL180M, and the second was rtM 204 Ⅰ. YMDD mutations were related to HBVDNA breakthrough and high ALT levels.