Antibody reactivity against animal retroviruses in multiple sclerosis

A total of 27 MS patients and 82 controls were studied for presence of antibodies reacting with maedi-visna virus and bovine leukemia virus by means of 2 ELISA techniques. Furthermore, the differentiated antibody response against BLV antigens was evaluated by immunoblotting. People with elevated activities against MVV were detected in the MS group as well as controls. Elevated antibody activity against BLV as determined by biotinylated protein A and peroxidase-labelled streptavidin tended to occur more frequently in MS patients than in controls. No such difference was found, however, when peroxidase-conjugated antibodies against human kappa chain were used for detection of antibodies reacting with BLV. Immunoblotting revealed no difference between the MS and the control group when anti-kappa antibodies were used to detect antibody binding to BLV antigens. The protein A method revealed significantly decreased antibody activity against a BLV antigen with molecular weight of about 29 kD in MS compared with controls, whereas a significant rise in number of MS patients responding to a component of about 53 kD was observed. The differences between the 2 detection systems could be due to unspecific reactions. The present data indicate that MS patients exhibit an inhomogeneous and, in some cases elevated, antibody activity against BLV.