Measles virus antibodies in serum and cerebrospinal fluid in patients with multiple sclerosis and other neurological disorders, with special reference to measles antibody synthesis within the central nervous system.

Measles virus hemagglutination-inhibiting (HI) and gel precipitating (GP) antibodies were determined in sera and cerebrospinal fluids (CSF) from 65 patinets with multiple sclerosis (MS) and 65 patients with other neurological diseases. The serological results were correlated to content of immunoglobulin-G (IgG) and electrophoretic patterns of sera and CSF. Measles GP antibodies, identified as directed against measles virus ribonucleoprotein antigens, were detected in sera and in CSF from a significantly higher proportion of MS than of non-MS patients. No significant difference between the 2 groups of patients was found for measles HI antibodies. Reduced serum/CSF HI and/or GP antibody ratios were found in about one half of the MS patients and in 2 patients with chronic myelopathy. All patients with reduced antibody ratios had evidence of IgG synthesis within the central nervous system (CNS), as inferred from oligoclonal IgG patterns of the CSF. Reduced ratios of measles GP antibodies were 3 times as common as reduced ratios of HI antibodies. Immunoelectrophoretic assays indicated that the CSF GP antibodies were electrophoretically restricted in a number of MS patients. The results indicate that measles virus may be an active immunogen within the CNS in many MS patients and in some patients with chronic myelopathy, giving rise to an oligoclonal IgG antibody response.