[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 (Pyronin), PCNA-FITC and PCNA-mouse-alpha-2a. The specimens were analyzed by a flow cytometer (FacS Caliber, 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.
Wang
Liang-xing
LX
Department of Respiratory Medicine, First Hospital, Affiliated Wenzhou Medicine School, Wenzhou 325003, China.
Chen
Wei-xun
WX
Wu
Jun
J
Chen
Shao-xian
SX
Huang
Xiao-ying
XY
Chen
Yan-fan
YF
D004247:DNA / Q000032:analysis; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016066:Pleural Effusion, Malignant / Q000175:diagnosis*; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D012313:RNA / Q000032:analysis; D012680:Sensitivity and Specificity
D018809:Proliferating Cell Nuclear Antigen; D012313:RNA; D004247:DNA