Multiple sclerosis and elevation of cerebrospinal fluid vaccinia virus antibody.

Thirty percent of 33 patients with a clinical diagnosis of multiple sclerosis and an elevation of cerebrospinal fluid (CSF) immunoglobulin G/albumin ratio greater than 2 standard deviations above the mean had elevation of the CSF vaccinia neutralizing antibody titer. Elevated titers were found in 1 of 23 patients with non-multiple sclerosis neurologic diseases and in none of the normal control patients. No linear correlation was found between the magnitude of the relative or absolute CSF immunoglobulin G concentration and the magnitude of the CSF vaccinia neutralizing antibody titers.