Abstract

In this study, a sandwich enzyme linked immunosorbent assay (ELISA) was developed to measure the concentration of cord factor (CF) antigen of M. tuberculosis in the pleural fluids of 42 patients with tuberculous pleural effusion (TPE). The assay was also simultaneously performed in 43 pleural fluid specimens with malignant pleural effusion (MPE). The assay detected CF antigen in 83.3% in patients with TPE effusion in whom M. tuberculosis was not demonstrated in pleural fluid specimens by bacteriological methods. The data also indicated that cord factor antigen was not present in significant titres in any one of the 43 pleural fluids of patients with MPE. It is concluded that estimation of cord factor of M. tuberculosis in pleural fluid specimens by the sandwich ELISA as developed in this study will support the diagnosis of tuberculous aetiology in pleural fluids, particularly in those patients in whom M. tuberculosis was not demonstrated by bacteriological methods.

Key words: Pulmonary tuberculosis, tuberculous pleural effusion (TPE), Mycobacterium tuberculosis, cord factor (CF) antigen, trehalose 6,6' dimycolate, enzyme-linked-immunosorbent assay (ELISA), malignant pleural effusion (MPE) specificity.