A newer approach for the laboratory diagnosis of tuberculous meningitis

In this prospective study, a simple method was standardized for measuring circulating mycobacterial antigen in the cerebrospinal fluid (CSF) for the laboratory diagnosis of tuberculous meningitis (TBM). The heat-inactivated CSF specimens from tuberculous and non-tuberculous patients were subjected to sodium dodecyl sulfate (SDS) - polyacrylamide gel electrophoresis (PAGE) (SDS-PAGE) and they were subsequently transferred onto nitrocellulose membrane (NCM) Using a rabbit polyvalent antibody to M tuberculosis, a heat stable 82 kDa mycobacterial antigen was demonstrated in the CSFs of patients with TBM. This antigen was conspicuous by its absence in the CSFs of non-tuberculous subjects. Due to inactivation of CSF specimens, there is a minimal risk of handling of infectious material in the laboratory. Besides, this newer approach is simple, inexpensive and can be readily applied in any routine clinical laboratory and it is particularly suited to developing countries.