title: A lack of association between hyperserotonemia and the increased frequency of serum anti-myelin basic protein auto-antibodies in autistic children.
abstract: BACKGROUND
  One of the most consistent biological findings in autism is the elevated blood serotonin levels. Immune abnormalities, including autoimmunity with production of brain specific auto-antibodies, are also commonly observed in this disorder. Hyperserotonemia may be one of the contributing factors to autoimmunity in some patients with autism through the reduction of T-helper (Th) 1-type cytokines. We are the first to investigate the possible role of hyperserotonemia in the induction of autoimmunity, as indicated by serum anti-myelin-basic protein (anti-MBP) auto-antibodies, in autism.
  
  
  METHODS
  Serum levels of serotonin and anti-MBP auto-antibodies were measured, by ELISA, in 50 autistic patients, aged between 5 and 12 years, and 30 healthy-matched children.
  
  
  RESULTS
  Autistic children had significantly higher serum levels of serotonin and anti-MBP auto-antibodies than healthy children (P < 0.001 and P < 0.001, respectively). Increased serum levels of serotonin and anti-MBP auto-antibodies were found in 92% and 80%, respectively of autistic patients. Patients with severe autism had significantly higher serum serotonin levels than children with mild to moderate autism (P < 0.001). Serum serotonin levels had no significant correlations with serum levels of anti-MBP auto-antibodies in autistic patients (P = 0.39).
  
  
  CONCLUSIONS
  Hyperserotonemia may not be one of the contributing factors to the increased frequency of serum anti-MBP auto-antibodies in some autistic children. These data should be treated with caution until further investigations are performed. However, inclusion of serum serotonin levels as a correlate may be useful in other future immune studies in autism to help unravel the long-standing mystery of hyperserotonemia and its possible role in the pathophysiology of this disorder.
authors.affiliation: Autism Research and Treatment Center, AL-Amodi Autism Research Chair, Department of Physiology, Faculty of Medicine, King Saud University, Riyadh, Saudi Arabia. hafezg@softhome.net
authors.forename: Gehan Ahmed
authors.initials: GA
authors.lastname: Mostafa
authors.forename: Laila Yousef
authors.initials: LY
authors.lastname: Al-Ayadhi
mesh_terms: D000818:Animals; D001321:Autistic Disorder / Q000097:blood* / Q000276:immunology* / Q000503:physiopathology; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D004676:Myelin Basic Protein / Q000276:immunology*; D012701:Serotonin / Q000097:blood*; D012720:Severity of Illness Index
chemical_list: D001323:Autoantibodies; D004676:Myelin Basic Protein; D012701:Serotonin