Investigation on differential diagnostic value of multi-index detection of pleural effusion.

Abstract

To study the roles of adenosine deaminase (ADA) , interferon gamma ( IFN-gamma) and carcinoembryonic antigen(CEA) for diagnosis of tuberculous and neoplastic pleural effusion. ADA , IFN-gamma and CEA activity in the serum and pleural fluid were detected in 67 patients with pleural effusion by the method of Guisti , a solid-phase enzyme-immunoassay employing the multiple antibody sandwich principle , and radioimmunoassay respectively. The mean ADA and IFN-gamma concentration in the tuberculous pleural effusion differed significantly from those in the neoplastic pleural effusion ( P < 0. 001) . The mean CEA concentration in the serum and pleural fluid with the neoplastic pleural effusion differed from those with the tuberculous pleural effusion ( P < 0. 05) . The sensitivity of ADA (with a diagnostic threshold of 40 U/L) and IFN-gamma(threshold of 140 pg/ mL) for tuberculosis was 88 % and 96 % respectively , the specificity was 85. 71 % and 97. 62 % , and diagnostic index was 73. 71 % and 93. 62 %. Using the ADA (with below 40 U/L) and IFN-gamma (below 140 pg/mL) and CEA (above 15mug/L) , we achieved a specificity of 95. 95 %for diagnosis of neoplastic pleural effusion. ADA , IFN-gamma and CEA are useful parameters in differential diagnosis of tuberculous and neoplastic pleural effusion.