Characterization of the Virus Antibody Activity of Oligoclonal IgG Produced in the Central Nervous System of Patients with Multiple Sclerosis

Abstract

There is at present no convincing direct evidence of a virus in the central nervous system (CNS) of multiple sclerosis (MS) patients. As mentioned by others, the evidence for such a virus is indirect, that is, serologic. Most of the studies have dealt with antibodies against measles. Adams and Imagawa showed in 1962 (1) that patients with MS had higher titers of measles antibodies than matched controls. Their observation was later confirmed in other studies (2), which demonstrated serum antibodies. We, together with our Finnish colleagues, also carried out such a study (7) in which we compared antibodies to three different components of measles virus, the internal, the nucleocapsid, and the two major envelope components—the hemagglutinin and the hemolysin. In all three serologic tests, one can detect differences in the mean titers between MS patients and the controls, which are carefully matched with regard to age and other characteristics. Furthermore, as shown in other studies (2), mean titers against measles of siblings of MS patients fall between the mean titers of MS patients and controls. Since the increased antibody titers are directed against three different components of the virus, it is highly likely that they represent a true antibody response to measles and not a cross reaction to some other antigen (4).