Antibodies against the paramyxovirus SV5 in the cerebrospinal fluids of some multiple sclerosis patients

Multiple sclerosis is a demyelinating disease of the central nervous system and although there is little doubt that an infectious agent (or agents) is involved (for reviews see refs 1 and 2) it has not been possible to demonstrate this unequivocally by any direct relationship to a given agent (see, for example refs 3-5). Here we show that a significant proportion of patients with multiple sclerosis have antibodies against the paramyxovirus SV5 (simian virus 5) in their cerebrospinal fluid and in some of these such antibodies form a major proportion of the total immunoglobulin content. Further, we have been able to demonstrate that the oligo-clonal bands displayed on electrophoresis of the cerebrospinal fluid of these patients can be removed by prior absorption with SV5 virus antigen.