title: Elevated serum levels of interleukin-17A in children with autism.
abstract: BACKGROUND
  The T-helper (Th)1/Th2 dichotomy dominated the field of immune regulation until interleukin (IL)-17-expressing T cells (Th17) were proposed to be a third lineage of helper T cells, the key players in the pathogenesis of autoimmune disorders. Autoimmunity to brain tissue may play a pathogenic role in autism. IL-17A is a pro-inflammatory cytokine that has been shown to play an important role in various autoimmune neuroinflammatory diseases. The aim of this study was to measure serum levels of IL-17A in relation to the degree of the severity of autism.
  
  
  METHODS
  Serum IL-17A levels were measured by ELISA in 45 children with autism and 40 matched healthy controls.
  
  
  RESULTS
  Children with autism had significantly higher serum IL-17A levels than healthy controls (P <0.001), with increased serum levels of IL-17A found in 48.9% of the autism group. Patients with severe autism had significantly higher serum IL-17A levels than those with mild to moderate autism (P=0.01), and raised serum IL-17A levels were significantly more common in children with severe autism (67.9%) than in those with mild to moderate autism (17.6%), P=0.001.
  
  
  CONCLUSIONS
  Serum IL-17A levels were raised in the group with autism, and the levels correlated significantly with the severity of autism. This is the first study to measure levels of IL-17A in relation to the severity of autism, to our knowledge. Further research, with a larger subject population, is warranted to determine whether the increase of serum IL-17A levels plasma has a pathogenic role in autism, and whether anti- IL-17A therapy could be useful.
authors: Department of Physiology, Autism Research and Treatment Center, Al-Amodi Autism Research Chair, Faculty of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors: Laila Yousef
authors: LY
authors: Al-Ayadhi
authors: Gehan Ahmed
authors: GA
authors: Mostafa
mesh_terms: D001321:Autistic Disorder / Q000097:blood / Q000175:diagnosis* / Q000209:etiology*; D015415:Biomarkers / Q000097:blood; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D020381:Interleukin-17 / Q000097:blood*; D008297:Male; D012307:Risk Factors; D044967:Serum / Q000378:metabolism*
chemical_list: D015415:Biomarkers; C508717:IL17A protein, human; D020381:Interleukin-17