The detection of antigen and antibody in cerebrospinal fluid of patients with tuberculous meningitis.

The ultimate diagnosis of tuberculous meningitis can be convincingly made through a positive culture of Mycobacterium tuberculosis from the cerebrospinal fluid (CSF). However, this process requires at least 6-8 weeks. Early diagnosis, preferably at time of presentation, is preferable to avoid the unfavorable sequelae. The detection of tuberculous antigen in the CSF of children with tuberculous meningitis was carried out by an ELISA technique. Anti-PPD in the CSF was detected by latex agglutination or measured by ELISA. CSF anti-PPD was not able to be detected by latex agglutination but was demonstrated by ELISA (titre > 1: 5). The sensitivity of test was 50 percent, with specificity of 94.7 percent and accuracy of 77.4 percent. Tuberculous antigen in the CSF, however, could not be detected by an ELISA technique used in this study (< 0.1 mcg/ml). We concluded that anti-PPD antibody by ELISA could be demonstrated in these children with tuberculous meningitis and this test could potentially be utilized in a clinical situation to aid in the rapid diagnosis of tuberculous meningitis patients.