多参数流式细胞术对恶性胸腔积液的诊断价值

目的应用流式细胞仪检测胸腔积液中的DNA、RNA、增殖细胞核抗原(PCNA),探讨多参数流式细胞术对恶性胸腔积液的诊断价值。方法2003年8月至2004年2月在我院呼吸内科住院治疗的胸腔积液患者47例,其中19例非肿瘤性胸腔积液患者作为对照组,28例经病理学检查确诊的恶性胸腔积液患者为试验组。采用碘化丙啶染色检测DNA,哌若宁染色检测RNA,PCNA-FITC法检测PCNA,阴性对照采用鼠-α-2a。用美国Becton Dickinson公司FacS Calibur流式细胞仪进行检测,计算单项检测和联合检测的敏感性和特异性。结果(1)非肿瘤性胸腔积液中DNA指数、RNA指数、PCNA流式细胞术检测结果分别为1.03±0.06、10.03±0.54及(4.86±0.72)%,而恶性胸腔积液为1.26±0.17、11.65±1.45及(11.97±1.50)%。诊断分界点分别为1.10%、10.75%、4.56%,此时的敏感性分别为89.3%、78.6%、75.0%,特异性为89.5%、98.5%、84.2%;(2)恶性胸腔积液中DNA指数正常而RNA指数异常者6例,表明流式细胞术同时检测患者RNA可以弥补DNA检测的不足;(3)5例患者胸腔积液中细胞学检查未发现肿瘤细胞,但其DNA指数和RNA指数均高于正常值,经多次胸膜活检或肺部肿块穿刺证实为恶性胸腔积液,表明流式细胞术对细胞学检查有补充作用;(4)DNA指数+RNA指数、DNA指数+PCNA的流式细胞术检测结果、RNA指数+PCNA的流式细胞术检测结果及三者联合诊断的敏感性分别为98.2%、89.3%、89.3%及92.9%,特异性为84.2%、89.5%、84.2%及94.2%。三者联合检测具有较低的漏诊率和误诊率,而对照组未发现三者同时高于诊断临界点的患者。结论流式细胞术检测胸腔积液DNA指数、RNA指数、PCNA的流式细胞术检测结果对于恶性胸腔积液的诊断具有一定的价值,特别是对于部分细胞学检测阴性的恶性胸腔积液的诊断可能具有重要的临床意义。DNA、RNA同时检测对于诊断DNA正常而RNA发生异常改变的恶性胸腔积液具有重要价值,可以弥补单项DNA检测的不足。三者联合检测对于恶性胸腔积液的诊断价值大于单项或两项联合检测,具有较低的漏诊率和误诊率。

Diagnostic value of DNA, RNA and proliferating cell nuclear antigen examination in malignant pleural effusions by flow cytometry

OBJECTIVE: To study the diagnostic value of DNA, RNA and proliferating cell nuclear antigen (PCNA) examination in malignant effusion by multiparametric flow cytometry, and therefore to provide proof for clinical application. METHODS: Forty seven patients with pleural effusions in our hospital from August 2003 to February 2004 were divided into two groups: 19 suffering from benign pleural effusions and 28 from malignant effusions confirmed by pathologic examination. The cells for diagnosis were divided into four groups stained by PI (Propidium-iodide), PY (Pyrenin), PCNA-FITC and PCNA-mouse-alpha-2a. The specimens were analyzed by a flow cytometer (FacS Calibur, Becton Dickinson). The sensitivity and the specificity of each examination and combined examination were calculated by statistic software SPSS 13.0. RESULTS: (1) The expression of DI, RI, and PI in benign pleural effusion was 1.03 +/- 0.06, 10.03 +/- 0.54, and (4.86 +/- 0.72)%, respectively, and those in malignant ones was 1.26 +/- 0.17, 11.65 +/- 1.45, and (11.97 +/- 1.50)%, respectively, the difference being statistically significant. The cutoff value of DI, RI and PI was 1.10%, 10.75% and 4.56%, and the sensitivity of DI examination was 89.3%, 78.6%, 75.0%, and the specificity was 89.5%, 98.5%, 84.2%, respectively. (2) In 6 cases suffering from malignant pleural effusions, RI was positive but DI was negative, indicating that DI combined with RI examination was better than DI examination alone. (3) In 5 cases suffering from malignant pleural effusions confirmed by tissue examination, the cytology was negative, but the result of DI and RI was abnormal, indicating that flow cytometry was complementary to pathologic examination. (4) The sensitivity of DI + RI, DI + PI, RI + PI and DI + RI + PI combined examination was 98.2%, 89.3%, 89.3%, 92.9%; the specificity was 84.2%, 89.5%, 84.2%, 94.2% respectively. The results demonstrated that DI + RI + PI combined examination was the best, which showed the least false negative and false positive results. The sensitivity of DI + RI combined examination was 98.2%, but the specificity was 84.2%, the false positive rate being higher than DI + RI + PI combined examination. In none of the benign pleural effusions was the DI + RI + PI higher than the cutoff value, suggesting that combined examination can exclude benign pleural effusions. CONCLUSIONS: DNA, RNA and PCNA examinations by flow cytometry are of value in the diagnosis of malignant effusion, especially for cases which can not be diagnosed by cytological examination. DI + RI + PI combined examination showed better results with the lowest false negative and false positive rates.