Characterization Molecular Biochemical Method for Diagnostic of Tuberculosis in the Pleural Samples

Objectives: To compare the diagnostic efficiency of adenosine deaminase, isoenzyme adenosine deaminase-2 and concentration of interferon- \gamma in patients with tuberculous pleural effusion. Materials and Methods: The prospective study was done on 114 patients who were divided into 3 groups: tuberculous, non-tuberculous infectious pleurisy, and malignant effusion. The adenosine deaminase, adenosine deaminase-2 and interferon- \gamma were analyzed by receiver operating characteristic curves. Results: There was increase of all three markers in tuberculous pleural effusion but not in nontuberculous effusion. The cut-off values for adenosine deaminase, adenosine deaminase-2 and interferon- \gamma were 40, 26 U/l. and 299 pg/ml respectively. Adenosine deaminase, adenosine deaminase-2 activities were significantly higher in tuberculous effusion than in malignant pleural effusion (more than 5 times) and in non-tuberculous infectious pleurisy (more than 4 times). The median of interferon- \gamma concentration in pleural fluid of tuberculous patients was 1514.2 pg/ml (931.2-2187.5pg/ml) which was 10 times more than the median values of other groups of patients. There was no significant difference between patients with malignant effusion and those with non-tuberculous pleural effusion. Conclusions: All three markers had higher diagnostic yield for tuberculous effusion.