基因芯片检测拉米夫定耐药的慢性乙型肝炎患者YMDD变异的初步研究

目的 用基因芯片技术检测拉米夫定耐药的慢性乙型肝炎患者乙型肝炎病毒(HBV)DNAP区YMDD基序变异情况。探讨变异对临床的影响，为疗效预测及制定进一步治疗措施提供依据。方法 取40例，临床考虑拉米夫定耐药患者的血清，用基因芯片的方法检测血清样本YMDD基序变异情况。观察变异检测阳性患者反跳时的丙氨酸氨基转移酶(ALT)水平及血清转换情况。结果 40例患者血清标本中，用基因芯片法检测HBV DNAP区YMDD变异，YMDD变异阳性标本27例，总变异检出率为67．5％(27/40)。单纯YMDD变异5例。YMDD变异株与野生株混合存在22例。在变异类型中，YIDD变异4例；YVDD变异16例；YIDD与YVDD混合变异7例。血清HBV DNA反跳时YMDD变异组ALT正常者有13例。40例患者中有3例发生血清转换，在YMDD变异检测阳性者中有1例发生血清转换。结论 在拉米夫定治疗过程中出现血清HBV DNA反跳时，多数患者血清中可以检出YMDD变异。反跳时变异株大多与YMDD野生株以共生形式存在，尤以YVDD变异为多，这可能是耐药变异出现后继续服用拉米夫定仍然有效的原因。用基因芯片技术能较好地检测YMDD变异情况，并能检测到患者体内变异株与野生株存在形式。

A pilet investigation of gene chips technique in detecting YMDD mutation in patients with drug-resistant chronic hepatitis B

Objective To investigate YMDD mutation in patients w ith lamivudine-resistant chronic hepatitis B(CHB), and to study influence of YMDD mutation on patients with CHB. Methods Gene chips was applied in detecting YMDD mutation in the region of HBV polymerase. The serum samples of 40 patients with CHB, considered lamivudine-resistant in clinic, were collected and tested. The parameters of alanine aminotransferase(ALT), HBV DNA, virology were compared between pre-treatment and after occurrence of YMDD mutation. These patients were followed up. Results Out of the 40 serum samples by gene chips technique, 13 cases were non-YMDD mutation, 27 cases were YMDD mutation positive, total mutation rate was 67.5% (27/40), including 4 cases of YIDD mutation, 16 cases of YVDD mutation, 7 cases of YIDD/YVDD double mutation. Wildtype and mutation coexisted in 22 cases. Total 3 cases in the 40 patients showed HBeAg seroconversion, there was 1 case in the YMDD mutation group. Conclusion According to the study, at the time of viral breakthrough, YMDD mutation was detected in most of the patients with drug-resistence in clinic during lamivudine treatment. Gene chips can be used to test YMDD mutation and wildtype of HBV DNA. Using this technique, the existing condition of YMDD mutation and wild type are found.