The Values Of Combined Pleural Effusion Testing Of Telomerase CEA And ADA For Differential Diagnosis Of Tuberculous And Malignant Pleural Effusion

Pleural effusion is a common clinical sign of many diseases. In our country, the major causes of pleural effusion are tuberculous and malignant ones, and the etiological diagnosis of pleural effusion are thus very important for the treatment and prognoses of the disease .Clinically, there is still about 20-30% of cases with pleura] effusion whose etiological diagnoses can not be made correctively. At present, telomerase is one of the hottest tumor markers being under investigation internationally, CEA is a marker with better specificity and wider application for the diagnosis of lung cancer and malignant pleural effusion, and ADA is an enzyme which can catalize deamination of adenosine into guanosine and has been used for the diagnosis of tuberculous pleural effusion after repeated research..Objective: To investigate the values of combined pleural effusion testing of telomerase, CEA and ADA for the differential diagnosis of tuberculous from malignant pleural effusion.Methods: 31 case with malignant and 35 case with tuberculous pleural effusion were enrrolled into our study. Telomerase activity in the pleural effusion was tested by means of PCR-ELISA, CEA levels in the pleural effilsion was tested by using EIAmethod and ADA contents in the Pleural effusion was tested by means of colorimetric analysis. All the results tested were analyzed statistically.Results: There were 27 cases with positive telomerase test in the group of malignant pleural effusion and 2 cases with mild positive telomerase test in the group of tuberculous pleural effusion. The sensitivity of telomerase activity testing for diagnosing malignant pleural effusion was 0.87, and 0.94 of the specificity. The corresponding positive predictives was 0.93, 0.89 the of the negative predictives and 0.91 of the correctiveness. The sensitivity of CEA testing for diagnosing malignant pleural effusion was 0.774, and 0.886 of the specificity. The sensitivity of ADA for diagnosing malignant pleural effusion was 0.839, and 0.914the specificity. The sensitivity of the combined testing of telomerase,CEA and ADA for diagnosing malignant pleural effusion was 0.967,0.971 of the specificity and 0.969 of the correctivenessConclusion: The activity testing of telomerase has important value on differential diagnosis of benign and malignant pleural effusion, but false negative and false positive results exist. The combined pleural effusion testing of CEA and ADA together with telomerase can be more valuable for the differential diagnosis of benign from malignant pleural effusion.