Diagnostic Value Of SB7-H4 And CEA Detection In Distinguishing Malignant From Benign Pleural Effusion

Background and Objective:Negative co-stimulatory molecule B7-H4,a new-emerging member of the B7 family,can down-regulate the immune responses by means of restraining T cell proliferation and activation,reducing the synthesis and secretion of relevant cytokine and blocking the progress of the cell cycle,and may be involved in tumor immune evasion.B7-H4 is widely high expressed in a variety of malignant tumor tissue and serum.Previous studies have proved that the levels of B7-H4 in malignant pleural effusion are significantly high.Our study aimed to investigate the diagnostic value of soluble B7-H4(sB7-H4)and carcinoembryonic antigen(CEA)for identifying malignant from benign pleural effusion in single or joint detection.Methods:Specimens from 97 initial treat patients with pleural effusion were collected from the First Affiliated Hospital of Zhengzhou University between January 2015 and December 2015.All cases were categorized into the malignant pleural effusion(MPE)group(n=55)and the benign pleural effusion(BPE)group(n=42)according to etiologies.Enzyme-linked immunosorbent assay(ELISA)was applied to examine the levels of sB7-H4 in pleural effusion and meanwhile CEA concentrations weredetected by means of electrochemiluminescence immunoassay.Receiver operating characteristic(ROC)curve was established to analyze and assess the diagnostic value of pleural effusion s B7-H4 and CEA in single or joint detection.The association analysis between sB7-H4 and CEA in pleural effusion was obtained by Pearson product-moment correlation.Results:(1)The levels of pleural effusion sB7-H4 in MPE and BPE group exhibited(60.08±35.04)ng/ml versus(27.26±9.55)ng/ml and meanwhile CEA concentrations were(41.49±37.16)ng/ml versus(2.41±0.94)ng/ml.However,there was statistical significance in both of them(P<0.01).(2)The area under curve(AUC)of ROC curve of pleural effusion sB7-H4 in MPE group was 0.884,and the diagnostic sensitivity and specificity were 81.82% and 90.48% respectively when sB7-H4 obtained 37.25ng/ml as an optimally clinical diagnosis threshold by means of ROC curve analysis;while AUC of CEA was 0.954,and the sensitivity and specificity were 87.28% and 95.24% respectively at the cut-off point of 4.18ng/ml.When two indicators above were combined,the sensitivity could be elevated to 90.91% and while the specificity was down to 88.10% in the parallel detection test,in which MPE was defined as sB7-H4 > 37.25ng/ml or CEA > 4.18ng/ml;in contrast,the sensitivity of the cascade connection detection test(for pleural effusion,s B7-H4> 37.25ng/ml and meanwhile CEA > 4.18ng/ml as MPE group)were down to78.18% and while the specificity was elevated to 97.62%.(3)The associative analysis result in MPE group showed the levels of pleural effusion sB7-H4 were positively correlated with CEA concentrations(P=0.001,r=0.470)and likewise the correlation between both of them was also positive in BPE group(P=0.001,r=0.002).Conclusions:sB7-H4 was a potentially valuable indicator in differentiating malignant from benign pleural effusion,which might not be superior to CEA.The combined detection of pleural effusion sB7-H4 and CEA could improve the diagnosticsensitivity and specificity for MPE.