Enzyme-linked immunosorbent assay to detect Mycobacterium tuberculosis antigen 5 and antimycobacterial antibody in cerebrospinal fluid of patients with tuberculous meningitis.

Inhibition ELISA and indirect ELISA was standardised to detect Mycobacterium tuberculosis antigen 5 and antimycobacterial antibody in cerebrospinal fluid (CSF) specimens of 75 patients with tuberculous meningitis, (TBM) and 75 patients with non-tuberculous neurological diseases (control group). In both ELISAs, no false-negative results were observed in 15 culture proven patients with TBM. Detection of M. tuberculosis antigen 5 is more sensitive than detection of antimycobacterial antibody. However, both ELISAs showed 100% specificity for tuberculous aetiology in culture-negative patients with TBM. ELISA should be considered as one of the approaches in the laboratory diagnosis of TBM, particularly when standard bacteriological methods are unable to demonstrate M. tuberculosis in CSF specimens of patients with TBM.