The intrathecal immune response in the early stage of multiple sclerosis.

Sequential pairs of cerebrospinal fluid (CSF) and serum samples from 10 patients followed for 2.5-12 years after onset of unilateral optic neuritis (ON) were studied. Eight patients developed definite multiple sclerosis (MS) during the observation period. All patients had normal CSF protein patterns on agar or agarose gel electrophoresis at onset. Six patients developed oligoclonal immunoglobulin (Ig) bands in the CSF during the observation period. Imprint immunofixation of electrofocused specimens disclosed intrathecal synthesis of oligoclonal IgG antibodies to 1 or more of 6 viruses (measles, herpes simplex type 1, varicella-zoster, cytomegalo, mumps, rota) during the observation period in 8 patients. Changes in patterns of intrathecally synthesized viral antibodies, characterized by the appearance of "new" antibody populations and the waxing or waning of others were observed in 6 patients. The results suggest that the early stage of MS in some patients is associated with transient as well as permanent recruitment of B cell clones producing viral antibodies of different specificities.