AFFINITY OF ANTIGEN-SPECIFIC IGG DISTINGUISHES MULTIPLE-SCLEROSIS FROM ENCEPHALITIS

The characteristics of antigen-specific IgG in patients with multiple sclerosis and patients with encephalitis have been compared. Both grou ps of patients showed antigen-specific oligoclonal bands locally synth esised in the CSF. When the affinity distribution of the antigen-speci fic IgG was measured there was a marked difference between the two gro ups. Encephalitis patients had high affinity antibody against the caus ative antigen. This was consistent with the antibody undergoing affini ty maturation as a result of the immune system fighting a primary infe ction. Multiple sclerosis patients lacked high affinity response. This lack of high affinity antibody was also seen in those encephalitis pa tients when antigens other than the causative antigen were studied.