中文摘要：

目的分析白血病患者血浆DNA的含量及完整性,并探讨其临床意义。方法以2008年6月-2009年3月收治的60例白血病患者作为实验组,同期在门诊行体检的健康正常人20例、血液系统良性病变者20例、淋巴瘤患者10例、实体肿瘤患者20例（食管癌6例、原发性肝癌4例、鼻咽癌5例、乳腺癌5例）作为对照组（n=70）。测定两组患者的血浆DNA含量,比较两组间、不同FAB分型的急性髓细胞白血病患者间、实验组不同年龄段及不同病程患者间血浆DNA水平的差异。采用聚合酶链反应扩增β-actin大片段和小片段产物并行琼脂糖凝胶电泳观察,比较实验组患者与对照组中正常人血浆DNA的差异。结果实验组患者血浆DNA浓度（413.2±118.4μg/L）约为对照组中正常人（19.6±7.9μg/L）的21倍（P〈0.05）,且高于对照组的其他疾病患者（P〈0.05）。实验组血浆DNA浓度与年龄及疾病病程有关,不同FAB型别的急性髓细胞白血病患者血浆DNA含量无显著差异。实验组血浆DNA电泳呈现大小不一的片段,而且其血浆DNA中可扩增出β-actin的大、小片段产物,完整性较高。正常人仅可见少量小片段DNA。结论白血病患者血浆DNA含量和完整性明显增高,对白血病的诊断及预后判断具有重要价值。

英文摘要：

Objective To evaluate the clinical significance of detection of both plasma DNA concentration and integrity in leukemia patients.Methods Sixty leukemia patients were assigned as experimental group,and the control group consisted of 70 subjects,including 20 healthy subjects for health check in out-patient clinic,20 patients with benign hematological diseases,10 cases of lymphoma and 20 cases of solid tumors（6 cases of esophageal carcinoma,4 cases of primary hepatic carcinoma,5 cases of nasopharyngeal carcinoma and 5 cases of breast cancer）.Plasma DNA of patients in the both groups were detected,and the differences in plasma DNA level were then compared respectively between the patients with different FAB types of acute myelocyte leukemia（AML）and those in experimental group with various age or clinical scenarios.Polymerase chain reaction（PCR）was performed to amplify large and short fragments of β-actin,and integrity of plasma DNA was analyzed with agarose gel electrophoresis.Results Mean concentration of plasma DNA in experimental group were（413.2±118.4）μg/L,which was about 21 times higher than that in the various control groups.The plasma DNA level in experimental group was closely correlated to age of patients and course of disease.However,no significant difference was found in plasma DNA concentrations between the subjects with different FAB subtypes.Agarose gel electrophoresis analysis showed a typical ladder pattern of DNA fragments from the plasma DNA in experimental group,and miscellaneous fragments of β-actin were amplified by PCR,demonstrating increased integrity in plasma DNA of leukemia patients,while only short products were amplified in healthy subjects.Conclusion Both the concentration and integrity of plasma DNA are increased in leukemia patients,which may have important clinical value in both diagnosis and monitoring prognosis for the leukemia patients.