Ide Tatsuya, Kumashiro Ryukichi, Koga Yuriko, Tanaka Eisuke, Hino Teruko, Hisamochi Akiko, Murashima Shiro, Ogata Kei, Tanaka Kazuo, Kuwahara Reiichiro, Sata Michio
Second Department of Internal Medicine, Kurume University School of Medicine, Kurume, Japan.
Am J Gastroenterol. 2003 Sep;98(9):2048-51. doi: 10.1111/j.1572-0241.2003.07643.x.
During treatment of chronic hepatitis B with lamivudine, changes in the level of hepatitis B virus (HBV) DNA were investigated using a real-time polymerase chain reaction (PCR) method with a detection limit of 1.7 log copies/ml (50 copies/ml) to clarify its clinical significance, particularly the association between HBV DNA levels and the emergence of tyrosine-methionine-aspartate-aspartate (YMDD) mutants.
Twenty-four patients who had received lamivudine therapy for >1 yr were studied. HBV DNA levels were determined using transcription-mediated amplification for sera with >3.7 log genome equivalents/ml, the Roche Monitor kit for sera with >/=2.6 log copies/ml, and real-time PCR for sera with < 2.6 log copies/ml (the detection limit was 1.7 log copies/ml). Patients were classified into three groups according to the minimal HBV DNA level attained during lamivudine therapy: the <1.7 log copies/ml group (eight patients), the 1.7-2.5 log copies/ml group (five patients), and the >/=2.6 log copies/ml group (11 patients).
Pretreatment HBV DNA levels were significantly lower in the <1.7 copies/ml group than in the other two groups (p < 0.05). Neither the emergence of YMDD mutants nor a virological breakthrough of serum HBV DNA was observed in any of the eight patients in the <1.7 copies/ml group. In contrast, in the 1.7-2.5 copies/ml and >/=2.6 copies/ml groups, virological breakthroughs resulting from the emergence of YMDD mutants were observed in two of five patients and in all 11 patients, respectively (p < 0.001). Virological breakthroughs were observed at a mean of 49.6 +/- 18.4 wk in 11 the patients in the >/=2.6 copies/ml group and at wk 107 and 115 in two patients in the 1.7-2.5 copies/ml group.
The real-time PCR method is useful for predicting the emergence of YMDD mutants and the estimated time of their emergence.
在使用拉米夫定治疗慢性乙型肝炎期间，采用检测限为1.7 log拷贝/毫升（50拷贝/毫升）的实时聚合酶链反应（PCR）方法研究乙型肝炎病毒（HBV）DNA水平的变化，以阐明其临床意义，特别是HBV DNA水平与酪氨酸-甲硫氨酸-天冬氨酸-天冬氨酸（YMDD）突变体出现之间的关联。
对24例接受拉米夫定治疗超过1年的患者进行研究。对于基因组当量/毫升>3.7 log的血清，使用转录介导的扩增法测定HBV DNA水平；对于拷贝/毫升≥2.6 log的血清，使用罗氏监测试剂盒；对于拷贝/毫升<2.6 log的血清（检测限为1.7 log拷贝/毫升），使用实时PCR法。根据拉米夫定治疗期间达到的最低HBV DNA水平将患者分为三组：<1.7 log拷贝/毫升组（8例患者）、1.7 - 2.5 log拷贝/毫升组（5例患者）和≥2.6 log拷贝/毫升组（11例患者）。
<1.7拷贝/毫升组的治疗前HBV DNA水平显著低于其他两组（p < 0.05）。<1.7拷贝/毫升组的8例患者中均未观察到YMDD突变体的出现或血清HBV DNA的病毒学突破。相比之下，在1.7 - 2.5拷贝/毫升组和≥2.6拷贝/毫升组中，分别有5例患者中的2例和11例患者中的全部患者观察到因YMDD突变体出现导致的病毒学突破（p < 0.001）。≥2.6拷贝/毫升组的11例患者中，病毒学突破平均出现在49.6 ± 18.4周，1.7 - 2.5拷贝/毫升组的2例患者分别在第107周和第115周出现病毒学突破。
实时PCR方法有助于预测YMDD突变体的出现及其出现的估计时间。
