Immunoglobulin-producing cells in blood and cerebrospinal fluid during the course of aseptic meningoencephalitis.

The protein A plaque assay was used to quantitate the number of IgG-, IgA-, and IgM-producing cells per 20 X 10(3) lymphocytes in cerebrospinal fluid (CSF) and peripheral blood (PB) from 23 patients with aseptic meningoencephalitis (AM) in the acute stage 1-10 days after onset (group I) and during late convalescence after 19-38 days (group II) and in PB from healthy controls. In the acute stage, IgG- and IgM-producing cells were found with significantly higher frequency in both CSF and PB than in the late convalescence. In both patient groups there were more Ig-producing cells in PB than in CSF. The predominant Ig class in PB of AM patients was IgA, just as in healthy individuals. In CSF, IgA- and IgG-producing cells predominated at similar frequencies. In the group I patients, there were positive correlations between numbers of Ig-producing cells of each class and the corresponding CSF Ig index, an indicator of intrathecal Ig synthesis. Since high numbers of Ig-producing cells could be found in CSF that was otherwise normal, enumeration of Ig-producing cells is considered a more sensitive indicator of the immune response intrathecally than measurement of free Igs.