Clinical Value Of TXNIP And CEA Detection In The Differential Diagnosis Between Benign And Malignant Pleural Effusions

Objective The purpose of this study was to primarily assess the clinical value of thioredoxin interacting protein(TXNIP) detection in pleural fluid and serum in the differential diagnosis between benign and malignant pleural effusions, compare it with carcino-embryonic antigen(CEA), and analyze combination tests if possible.Methods Clinical specimens of plural fluid and serum were collected from 57 patients with pleural effusions, of which 25 were clinically confirmed as malignant pleural effusions and 32 as benign ones. The levels of TXNIP and CEA in each specimen of plural fluid and serum were measured by enzyme linked immunosorbent assay(ELISA). The differences between groups of benign and malignant pleural effusions were analyzed. If there was statistical difference for some index, the diagnostic sensitivity and specificity for malignant pleural effusions would then be calculated and analyzed further.Results The concentration of TXNIP in plural fluid in the group of malignant pleural effusions was lower than that in the benign pleural effusions group [(77.36±17.58) ng/ml vs.(112.00±16.13) ng/ml, P<0.05]. However, there was no statistical difference between the levels of serum TXNIP in two groups [(117.28±14.90) ng/ml vs.(123.52±23.52) ng/ml, P>0.05]. For CEA, the levels in both plural fluid and serum in malignant pleural effusions group were higher than those in benign one [(21.00±20.86) ng/ml vs.(2.80±1.71) ng/ml,(10.65±7.78) ng/ml vs.(2.35±1.29) ng/ml; both P<0.05]. With receiver operating characteristic curve analysis used and the optimal cut-off points selected then, the indices of diagnostic efficiency of TXNIP in pleural fluid for malignant pleural effusions(TXNIP ≤ 89.57 ng/ml as malignant) were: sensitivity 76.00%, specificity 87.50%, accuracy 86.96%; while those indices of CEA in pleural fluid for malignant pleural effusions(CEA ≥ 5.29 ng/ml as malignant) were: sensitivity 88.00%, specificity 90.60%, accuracy 91.23%. When the above two examinations were combined, the diagnostic sensitivity and specificity of parallel test for malignant pleural effusions(for plural fluid examination, TXNIP ≤ 89.57 ng/ml OR CEA ≥ 5.29 ng/ml as malignant) were 97.12% and 79.28%, respectively; while the sensitivity and specificity of cascade connection test(for plural fluid examination, TXNIP ≤ 89.57 ng/ml AND CEA ≥ 5.29 ng/ml as malignant) were 66.88% and 98.83%, respectively.Conclusions Detection of TXNIP in pleural fluid might be of certain reference value in the differential diagnosis between benign and malignant pleural effusions, which may not be superior to CEA detection. Combination tests of the above two examinations could lead to a higher diagnostic sensitivity or specificity for malignant pleural effusions.