The Diagnostic Value Of Combined Detection PCT And CEA In Malignant Pleural Effusion

Objective: Tuberculosis and malignant pleural effusions are frequently seen in exudate, the therapy and prognosis of the two kinds of effusions is very different. We need to define the etiology promptly and specifically, so the patients with effusion can receive effective therapy .Nowadays, the discrimination between them is still difficulty in our clinic work. Procalcitonin (PCT, Procalcitonin) is a kind of calcitonin peptide substances, with non-hormone activity, 116 amino acid composition, molecular weight of 13 Kd glycoprotein. The current study reports on the PCT, mainly for the early diagnosis of systemic infection and sepsis, differential diagnosis of bacterial infection and viral infection, fever of unknown origin, serious infections after organ transplantation and rejection of acute and chronic complications, Continuous detection of the above disease, observation of curative effect and prognosis, guidance for clinicians to the proper use of antibiotics. For the concentration of PCT in the cerebrospinal fluid and other body fluids such as ascites, there were also researches at home and abroad .But the study of PCT in pleural effusion was reported in less .CEA (carcino-embryonic antigen, CEA) is the marker of malignant pleural effusions, which has a wider application in differential diagnosis of benign and malignant pleural effusions in clinic work . The purpose of this study is to observe the diagnostic value of combined detection procalcitonin(PCT) and CEA in malignant pleural effusion.Methods: In this study, Collected 95 cases of patients with pleural effusion in our hospital. Upon the patients informed consent, 15ml pleural effusion would be saved while the first thoracentesis was performed, and 3ml venous blood saved in the morning with the patients empty stomach, for the PCT and CEA test. In the latter part of our study, executed comprehensive analysis to collected cases. CEA and PCT levels would be detected for pleural effusion which had clear etiological diagnosis. The cases through clinical and laboratory data which were not given a clear diagnosis would be ruled out .By histopathology or cytology malignant pleural effusion was confirmed. Suit for any one of the following condition diagnosis as tuberculous pleural effusion:(1)After pleural biopsy, found nodular tuberculosis and cheese-type necrosis or cultivate mycobacterium tuberculosis(2)Detection of acid-fast bacillus in sputum;(3)In line with the tuberculosis toxemic symptoms and with clinical and X-ray performance,higher value of pleural fluid ADA, experimental anti-tuberculosis treatment was effective and eliminated other causes of exudative pleural effusion. Exclusion criteria:①After detailed examination and clinical observation the diagnosis had not yet confirmed;②with the situation that would increased the PCT concentration in pleural effusion :acute respiratory distress syndrome, after severe trauma and surgery, transplantation and the use of anti-rejection drugs, chemical pneumonia and so on. After bolting, 30 cases with malignant and 19 cases with tuberculous pleural effusion were enrolled into the study. Enzyme linked immunosorbent assay was used to detect PCT of plasma and pleural effusion, and CEA levels were tested by using radio-immunity .Data were expressed by x±s, using statistical analysis software SPSS12.0.The comparison between two groups was used t-test,used receiver operating characteristic curve (ROC curve) to analyse and evaluate of experimental data and determine the diagnostic value. Paialleled and paralleled the two tests to assess the specificity and sensitivity, and the value of different test strategies in diagnosing pleural effusion.Results: In accordance with the inclusion criteria and exclusion criteria, 30 cases with malignant (MPE group)and 19 cases with tuberculous pleural effusion(TB group) were enrolled into the study. Our stydy showed that the levels of PCT in malignant pleural effusion were higher than tuberculous pleural effusion(0.373μg/L±0.276μg/L, 0.202μg/L±0.121μg/L,P=0.005),no difference was observed in plasma .Diagnostic sensitivity and specificity value for PCT in malignant effusion were 67% and 74% at the 0.221μg/L cut-off value, 83% and 84% for CEA at 15μg/L, When paialleled the two tests, the specificity can elevate to 95%, parallel detection can elevate the sensitivity to 97%.Combined detection was better than the single test.Conclusions: The detection of PCT had certain value for diagnosing malignant pleural effusion, the combined testing of PCT and CEA can improve the specificity and sensitivity significantly, but the diagnostic value of PCT was not better than CEA.