中文摘要：

目的监测成人急性淋巴细胞白血病（ALL）患者化疗过程中的血浆DNA水平,初步探讨其与ALL化疗疗效的关系。方法采集55例成人ALL患者化疗前及其中45例患者化疗一疗程后的静脉血,根据骨髓象、血象及临床体征进行疗效分组。以80名体检健康者作为对照。用磁珠法提取血浆DNA和内参照质粒DNA,双重荧光定量PCR技术进行DNA定量检测。结果 ALL患者化疗前血浆DNA含量[M（P25,P75）]为248.1（97.1,448.7）ng/mL,显著高于健康对照组19.1（12.7,25.8）ng/mL（Z=8.916,P〈0.01）;化疗一疗程后血浆DNA含量为35.5（17.7,83.0）ng/mL,显著低于化疗前水平（Z=6.322,P〈0.01）;不同疗效化疗前组血浆DNA水平有显著性差异（χ2=6.960,P〈0.05）,不同疗效组化疗后血浆DNA水平有显著性差异（χ2=11.145,P〈0.01）。完全缓解组化疗前、后血浆DNA水平有显著性差异（Z=3.92,P〈0.01）,部分缓解组、未缓解组化疗前、后无显著性差异。生存曲线分析显示,化疗一疗程后血浆DNA水平〈50 ng/mL的ALL患者生存率高于血浆DNA水平≥50 ng/mL的患者（χ2=3.860,P〈0.05）。结论血浆DNA定量检测对ALL的化疗疗效评价及预后评估有重要意义。血浆DNA水平降低提示预后良好。

英文摘要：

Objective To monitor the levels of plasma DNA in the chemotherapy process of adult patients with acute lymphocytic leukemia （ALL） , and evaluate the relationship between plasma DNA level and chemotherapy efficiency. Methods Venous blood samples were taken from 55 adult patients with ALL before chemotherapy and 45 of them after one course of chemotherapy. The patients were divided into three groups according to the chemotherapy efficiency judged by bone marrow myelogram, hemogram and clinical manifestations. Eighty healthy subjects were selected as controls. The plasma DNA was extracted with magnetic beads, and the levels of plasma DNA were determined by duplex real-time PCR with the plasmid DNA as internal reference. Results The plasma DNA level [ M（ P25 , PTs ） ] in the patients with ALL before chemotherapy was 248.1 （97.1,448.7） ng/mL, which was significantly higher than that of the control group [ 19.1 （ 12.7, 25.8） ng/mL, Z = 8. 916, P 〈 0.01 ]. After one course of chemotherapy, the plasma DNA level was 35.5 （ 17.7, 83.0） ng/mL, which was markedly lower than that before chemotherapy （ Z = 6. 322, P 〈 0.01 ）. There was significant difference of plasma DNA levels among the three groups with different curative effect whether before chemotherapy （χ2 = 6. 960, P 〈 0.05 ） or after chemotherapy （χ2 = 11. 145, P 〈 0.01 ）. However, there was significant difference of plasma DNA levels before and after chemotherapy （Z = 3.92, P 〈 0.01 ） in the complete remission group, but no significant difference in the partial remission group and non-remission group. The analysis of Kaplan-Meier survival curves showed that the survival rate of patients with plasma DNA less than 50 ng/mL was higher than that of patients with plasma DNA more than or equal to 50 ng/mL （χ2 =3. 860, P 〈0.05） after one course of chemotherapy. Conclusions The determination of plasma DNA level may have important significance for evaluating the curative effect and prognosis of acute lymphocytic leukemia.