We will present a comparison of serum antineuronal antibody profiles in children with OCD-only (n=13), PANDAS + OCD (n=20), CTD + OCD (n=23), and age-matched controls (n=29). Detection methods used to evaluate anti-brain antibodies included immunohistochemistry (striatum), ELISA (BA 9/10, BA 11, caudate, and cingulate gyrus), and Western immunoblotting (BA 9/10, BA 11, caudate, and cingulate gyrus).

Immunublotting was further used to assess the presence and concentration of putative antigens identified in post-streptococcal patients, i.e., *- and *-enolase, aldolase C, pyruvate kinase M1 and tubulin. Anti-lysoganglioside GM1 activity was measured by competitive inhibition.