Demonstration of specific antibodies in the central nervous system of horses naturally infected with Borna disease virus.

From 18 horses with clinical symptoms of an affection of the central nervous system and with histopathologic alterations in the brain, four were demonstrated to have Bornavirus-specific antibodies. The antibodies are monospecific, recognizing identical antigens from infected brains of different animal species as well as from persistently infected tissue culture cells. Discrete immunoglobulin species (oligoclonal IgG) can be demonstrated in concentrated horse cerebrospinal fluid; they carry Bornavirus antibody specificity. Their presence, together with the higher antibody titers in the cerebrospinal fluid as compared to those in the serum, indicate that in these natural Bornavirus infections local antibody production occurred in the central nervous system.