ELISA using mycobacterial antigens as a diagnostic aid for tuberculous meningitis.

An enzyme-linked immunosorbent assay (ELISA) was studied as a possible laboratory test to aid in the diagnosis of tuberculous meningitis (TBM) in an Indian population. The assay detected mycobacterial antibodies in the cerebrospinal fluid (CSF) of TBM patients. Three antigens, PPD, BCG and M. tuberculosis were tested for use in the assay and of these, M. tuberculosis was found to be the most suited. A sensitivity of 72% and specificity of 92% with M. tuberculosis as antigen was obtained for the ELISA under discussion. The system therefore does hold promise as a diagnostic laboratory test for TBM.