[The value of B7-H4 and carcinoembryonic antigen in diagnosing the benign and malignant pleural effusion].

To evaluate the value of combined detection of negative costimulatory molecule B7-H4 and carcinoembryonic antigen (CEA) in diagnosing malignant and benign pleural effusion. Ninety-seven pleural effusion specimen were collected, 55 of which were diagnosed as malignant pleural effusion and 42 were benign pleural effusion. Enzyme-linked immunosorbent assay(ELISA) was used to examine the concentration of B7-H4 and CEA in pleural effusion. Electro-chemiluminescence immunoassay was used to detect the CEA level in pleural effusion. Receiver operating characteristic (ROC) curve was established to analyze and evaluate the single or combined detection of B7-H4 and CEA in diagnosing malignant and benign pleural effusion. The concentrations of B7-H4 and CEA in malignant pleural effusion (MPE) group were (60.08±35.04) ng/ml and (41.49±37.16) ng/ml, respectively, obviously higher than (27.26±9.55) ng/ml and (2.41±0.94) ng/ml of benign pleural effusion (BPE) group (both <0.01). Area under curve (AUC) of B7-H4 was 0.884 in MPE groupand the diagnostic sensitivity and specificity were 81.8% and 90.5%, respectively, at the optimized cut off value of 37.25 ng/ml. Likewise, area under curve (AUC) of CEA was 0.954 and the sensitivity and specificity were 87.3% and 95.2%, respectively, at the cut off value of 4.18 ng/ml. When B7-H4 >37.25 ng/ml or CEA>4.18 ng/ml, the sensitivity of diagnosis as MPE was down-regulated to 90.9% and the specificity was elevated to 88.1%. When B7-H4 >37.25 ng/ml and CEA>4.18 ng/ml, the sensitivity of diagnosis as MPE was down-regulated to 78.2% and the specificity was elevated to 97.6%. The sensitivity and specificity of combined detection of B7-H4 and CEA to diagnose MPE were elevated to 90.9% and 97.6%, respectively. The level of B7-H4 in MPE and BPE were both positively correlated with CEA (=0.670, =0.001 in MPE and =0.002, =0.001 in BEP). B7-H4 is a potential tumor marker in diagnosing the benign and malignant pleural effusion. Although the diagnostic value of B7-H4 may not precede to CEA, the combined detection of B7-H4 and CEA can improve the diagnostic sensitivity and specificity of MPE.