Viral IgM and IgG antibody synthesis within the central nervous system in mumps meningitis

With the use of enzyme-linked immunosorbent assay (ELISA) for demonstration of specific viral antibodies in 21 patients with mumps meningitis (MM), 19 (91%) displayed evidence for synthesis within the central nervous system (CNS) of IgG antibodies and 11 (52%) of IgM antibodies. Only one MM patient did not show local antibody production, but he had high mumps IgM titers in serum. Elevated IgG and IgM indices reflecting local IgG and IgM production, were found in 4 (19%) and 17 (81%) of the patients, respectively, and frequently did not coincide with local synthesis of specific antibodies. None of 21 control patients with acute aseptic meningitis of other etiology showed evidence for a local antibody response against mumps. In one of the MM patients, local production of measles IgM antibodies was demonstrated, reflecting an IgM response within the CNS against an antigen unrelated to the disease. This study concludes that in less serious CNS infections, such as MM, highly sensitive methods as ELISA are needed to demonstrate intrathecal specific viral immune response.