中文摘要：

目的检测不同级别脑胶质瘤患者血清及脑脊液中游离DNA的含量及完整性，探讨其对脑胶质瘤的诊断及预后判断的意义。方法术前采集70例脑胶质瘤患者和22例健康对照的外周血；其中30例胶质瘤患者同时采集脑脊液。通过实时荧光定量聚合酶链反应（RT—qPCR）方法检测血清及脑脊液中游离DNA短串联重复序列（ALU）的长片段（247bp）与短片段（115bp）的含量以及DNA完整性。结果血清中ALU-247bp与115bp含量以及游离DNA完整性在胶质瘤组与对照组间差异无统计学意义（P〉0．05）。脑脊液中游离DNAALU-247bp与115bp含量均较非肿瘤对照组高，DNA完整性（ALU．247／ALU-115bp）较对照组也显著增高。ROC曲线分析ALU．247bp，ALU-115bp含量与DNA完整性的AUC分别为0．775、0．875和0．912。结论胶质瘤患者术前脑脊液中游离DNAALU-247bp、ALU-115bp的含量以及DNA完整性对胶质瘤的术前诊断具有一定价值。

英文摘要：

Objective To detect the content of free DNA and the DNA integrity in serum and ce- rebrospinal fluid （CSF） from glioma patients in order to assess their diagnostic value for the glioma. Meth- ods Serum samples were obtained from 70 patients with glioma and 22 healthy volunteers as controls, and CSF samples from 20 patients with glioma and 8 nonneoplastic controls with hydrocephalus or arachnoid cyst. Free DNA concentration and integrity were detected by using real-time quantitative polymerase chain reaction （RT-qPCR） before operation. With 2 primers sets amplifying short and long free DNA fragments （ALU115 and ALU247 ） , free DNA integrity was determined by ratio of the concentration of ALU247 over ALUll5 （ALU 247/115 ）. Results The concentration of serum ALU had no significant differences be- tween glioma patients and healthy controls. ALU115 and ALU247 contents, and free DNA integrity in CSF were significantly higher in glioma patients than in the controls （ all P 〈 0. 05 ）. Area under curve of ROC curve analysis for the CSF free DNA integrity, and content of ALU115 and ALU247 for the diangosis of gli- oma was 0. 912, 0. 775 and 0. 875, respectively. Conclusion The CSF free DNA concentration and integ- rity may serve as a new marker for the diagnosis of glioma.