A sensitive ELISA system for the rapid detection of virus specific IgM antibodies in the cerebrospinal fluid

The intrathecal production of IgM antibodies to different viral antigens was measured by a modification of ELISA that was both sensitive and specific. Suitably diluted CSF and homologous serum samples containing similar amount of IgM were examined, and a comparison of the photometric signals permitted the detection of specific antibodies secreted from activated lymphocytes into the CSF compartment during the course of viral infections of the central nervous system. Polyvinyl chloride (PVC) microtitre plates were activated by glutaraldehyde and then coated with different viral antigens. Test samples were incubated on these solid-phase antigens and virus-specific IgM antibodies were detected using a peroxidase-conjugated F (ab')2 fragment of anti-human IgM antibody to avoid interference from rheumatoid factors.