Serodiagnostic potentialities of enzyme-linked immunosorbent assay (ELISA) using mannophosphoinositides of Mycobacterium tuberculosis H37Rv.

The serological response to mannophosphoinositides of Mycobacterium tuberculosis H37Rv and to tuberculin-purified protein derivative (PPD) was examined by enzyme-linked immunosorbent assay (ELISA) in patients suffering from tuberculosis and related diseases. In sputum positive cases 94% samples were found to be positive to mannoside antigens and 77% to PPD, while in sputum negative cases, 71% of samples gave a positive reaction to mannosides and 54% to PPD. The high specificity of mannoside ELISA was demonstrated to be 97% in healthy individuals and 100% in patients suffering from other respiratory diseases, whereas PPD ELISA was 84% and 82% in healthy and infected patients respectively. Thus, ELISA is more specific and sensitive for mannosides than for PPD for the diagnosis of tuberculosis. However, antibodies to mannosides and PPD were detected in lepromatous as well as tuberculoid leprosy patients.