Measles virus infection and multiple sclerosis: serological studies.

In 159 patients out of 161 with multiple sclerosis (MS), a significant rise in the level of measles hemagglutination inhibition (HI) antibody was found in the serum and in 92 MS patients the occurrence of measles HI antibody in the CSF was significantly more frequent. MS patients showed CSF humoral response against measles virus by neutralizing test (NV) (76%) more often than by hemagglutination test (37%). CSF FA antibody was found in 60%. In the serum of MS patients the presence of NV, HAd, FA, and GP-RNP was observed. 87% of MS patients showed lowered serum: CSF NV or HI antibody ratios and 78% had a diminished FA antibody ratio. Longitudinal study of serum HI measles virus antibody showed no substantial changes over longer period of the disease. Higher CSF measles antibody titer was found in more disabled patients with a malignant course of the disease (P less than 0.001). It is concluded that either persistent infection with proviruses or nonspecific stimulation of certain clones in individuals with genetic susceptibility provides for an excessive synthesis of humoral viral antibodies in MS.