title: Antibody binding to neuronal surface in Sydenham chorea, but not in PANDAS or Tourette syndrome.
abstract: OBJECTIVE
  To test the hypothesis that Sydenham chorea (SC) immunoglobulin G (IgG) autoantibodies bind to specific neuronal surface proteins, whereas IgG from patients with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) or Tourette syndrome (TS) do not bind to neuronal surface proteins.
  
  
  METHODS
  We used live differentiated SH-SY5Y cells, which have neuronal and dopaminergic characteristics. Using flow cytometry, we measured serum IgG cell surface binding in patients with SC (n = 11), PANDAS (n = 12), and TS (n = 11), and compared the findings to healthy controls (n = 11) and other neurologic controls (n = 11). In order to determine the specificity of binding to neuronal antigens, we also used a non-neuronal cell line, HEK 293.
  
  
  RESULTS
  The mean IgG cell surface binding was significantly higher in the SC group compared to all other groups (p < 0.001). By contrast, there was no difference between the PANDAS or TS groups and the controls. Using the non-neuronal HEK-293 cells, there was no significant difference in IgG cell surface binding between any groups.
  
  
  CONCLUSIONS
  Serum autoantibodies that bind to neuronal cell surface antigens are present in SC, but not in PANDAS or TS. These findings strengthen the hypothesis that SC is due to a pathogenic autoantibody, but weaken the autoantibody hypothesis in PANDAS and TS.
authors.affiliation: Neuroimmunology Group, Institute for Neurosciences and Muscle Research, The Kids Research Institute at the Children's Hospital at Westmead, University of Sydney, Australia. fabiennb@chw.edu.au
authors.forename: F
authors.initials: F
authors.lastname: Brilot
authors.forename: V
authors.initials: V
authors.lastname: Merheb
authors.forename: A
authors.initials: A
authors.lastname: Ding
authors.forename: T
authors.initials: T
authors.lastname: Murphy
authors.forename: R C
authors.initials: RC
authors.lastname: Dale
mesh_terms: D000293:Adolescent; D000970:Antineoplastic Agents / Q000494:pharmacology; D001327:Autoimmune Diseases / Q000097:blood / Q000276:immunology; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor; D002648:Child; D002675:Child, Preschool; D002819:Chorea / Q000097:blood / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism*; D008297:Male; D009447:Neuroblastoma / Q000473:pathology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009771:Obsessive-Compulsive Disorder; D018709:Statistics, Nonparametric; D013290:Streptococcal Infections / Q000097:blood / Q000276:immunology; D005879:Tourette Syndrome / Q000097:blood / Q000276:immunology*; D014212:Tretinoin / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D007074:Immunoglobulin G; D014212:Tretinoin