Sub acute and chronic meningitis in children--an immunological study of cerebrospinal fluid.

Cerebrospinal fluid (CSF) from 274 cases of subacute to chronic meningitis in age groups from 3 months to 12 years were analysed for the presence of antibody response to mycobacterial and cysticercal antigens by enzyme linked immunosorbent assay (ELISA). Simultaneously other correlative parameters such as CSF cell cytology by cytospin studies, mycobacterial antigens of Lipoarabinomannan (LAM) type (a polysaccharide antigen) by reverse passive haemagglutination assay (RPHA) CSF C-reactive protein (CRP) by latex agglutination and microbial cultures for mycobacterium tuberculosis and fungi were carried out. Antimycobacterial antibody was present in 35.4% of the cases. In 57.66% of the cases there was no demonstrable immune response to either mycobacterial or cysticercal antigens. However, it was interesting to note that 5.47% of the cases revealed the presence of anticysticercal antibody in the CSF. The mycobacterial antigen (LAM polysaccharide antigen) was found in 72.6% of the cases. There was no evidence of carcinomatous or cryptococcal meningitis. This study stresses the role of multimodal diagnostic tests on CSF for investigating cases of chronic and subacute meningitis irrespective of leading clues such as tuberculosis.