儿童急性淋巴细胞白血病微量残留病细胞的DNA定量研究

Quantitative analysis of minimal residual disease cells DNA in children with acute lymphoblastic leukemia

目的探讨定量监测儿童急性淋巴细胞白血病（ＡＬＬ）微量残留病（ＭＲＤ）细胞ＤＮＡ变化的临床意义。方法采用５′端修饰引物，构建内参照竞争模板，建立竞争性聚合酶链反应（ｃｏｍｐｅｔｉｔｉｖｅｐｏｌｙｍｅｒａｓｅｃｈａｉｎｒｅａｃｔｉｏｎ，ＣＰＣＲ）ＤＮＡ（ＣＰＣＲＤＮＡ）定量法，对７０例ＡＬＬ患儿进行了Ｔ细胞受体（Ｔｃｅｌｒｅｃｅｐｔｏｒ，ＴＣＲ）Ｖδ２Ｄδ３基因重排定性检测及完全缓解（ＣＲ）期ＭＲＤ的动态定量研究。结果（１）ＴＣＲＶδ２Ｄδ３基因重排检出率：在７０例ＡＬＬ中占８１％，４８例ＢＡＬＬ中占８３％，４例ＴＡＬＬ中占１／４，后两者比较差异有显著意义（Ｐ＜００５）。（２）ＭＲＤＤＮＡ定量监测显示：①随ＣＲ期延长（除ＣＲ＜３个月者），ＭＲＤ水平呈逐年下降趋势，以ＣＲ４～１２个月ＭＲＤ水平最高，并与骨髓复发呈正相关。②９例复发者于复发前平均７个月即出现ＭＲＤ增高，分子水平的改变先于临床复发。③ＡＬＬ持续完全缓解（ＣＣＲ）３年以上，ＭＲＤ持续转阴或持续≤００５％，可作为终止化疗的可靠指标。结论（１）建立了一种简捷、敏感、准确的ＣＰＣＲＤＮＡ定量法；（２）用该ＣＰＣＲ方法定量监测ＭＲＤ变化，对判断?

Objective To explore the clinical significance of quantitative analysis of minimal residual disease (MRD) cells DNA in children with acute lymphoblastic leukemia (ALL). Methods By using the competitive polymerase chain reaction (CPCR) technique which was based on the 5terminal modified primers to obtain the internal standard template, the Tcell receptor (TCR)V2D3 gene rearrangements were detected in 162 bone morrow samples collected from 70 patients with ALL, and MRDDNA were analysed quantitatively in patients with complete remission (CR). Results (1) The frequencies of TCR V2D3 rearrangements were 81% in ALL, 83% in BALL and 1/4 in TALL, respectively. (2)MRDDNA was detected in 92 samples collected from 48 patients with CR, and the MRD showed a descending tendency year by year in the patients, but not the patients with CR less than 3 months. The highest MRD DNA level was found in the patients with CR of 412 months and showed a positive correlation with the relapse of ALL. MRDDNA was elevated (>0.05%) 7 months prior to the relapse. The patients with continuous complete remission (CCR) over 3 years and with negative MRD or MRD0.05% persistently could be considered to terminate the chemotherapy. Conclusion The CPCR method was a simple, sensitive and accurate MRDDNA quantitative method. It may play an important role in evaluating the chemotherapy efficiency, predicting relapse and prognosis and guiding clinical