Anti-streptococcal antibodies reacting with brain tissue. II. Utrastructural studies

The reaction of rabbit anti-Streptococcus pyogenes type 24 with mouse brain has been studied at the ultrastructural level using horseradish peroxidase labelled antiglobulin. It is shown that these antibodies, and by inference those found in Sydenham's chorea, react with the fibrous astrocyte. The cross-reacting antigen is the glial filament or a closely associated cytoplasmic constituent.