title: Elevated serum levels of macrophage-derived chemokine and thymus and activation-regulated chemokine in autistic children.
abstract: BACKGROUND
  In some autistic children, there is an imbalance of T helper (Th)1/Th2 lymphocytes toward Th2, which may be responsible for the induction of the production of autoantibodies in these children. Th2 lymphocytes express CCR4 receptors. CCR4 ligands include macrophage-derived chemokine (MDC) and thymus and activation-regulated chemokine (TARC). They direct trafficking and recruitment of Th2 cells. We are the first to measure serum levels of CCR4 ligands in relation to the degree of the severity of autism.
  
  
  METHODS
  Serum concentrations of MDC and TARC were measured, by quantitative sandwich enzyme immunoassay technique, in 56 autistic children and 32 healthy matched children.
  
  
  RESULTS
  Autistic children had significantly higher serum levels of MDC and TARC than healthy controls (P <0.001 and P <0.001, respectively). Children with severe autism had significantly higher serum levels of MDC and TARC than patients with mild to moderate autism (P <0.001 and P = 0.01, respectively). In addition, there were significant positive correlations between CARS and serum levels of both MDC (P <0.001) and TARC (P <0.001) in children with autism. There were significant positive correlations between serum levels of MDC and TARC in autistic children (P <0.001).
  
  
  CONCLUSIONS
  Serum levels of CCR4 ligands were elevated in autistic children and they were significantly correlated to the degree of the severity of autism. However, further research is warranted to determine the pathogenic role of CCR4 ligands in autism and to shed light on the therapeutic role of CCR4-ligand antagonism in autistic children.
authors.affiliation: Autism Research and Treatment Center, Department of Physiology, Faculty of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Laila Yousef
authors.initials: LY
authors.lastname: Al-Ayadhi
authors.forename: Gehan Ahmed
authors.initials: GA
authors.lastname: Mostafa
mesh_terms: D001321:Autistic Disorder / Q000097:blood* / Q000276:immunology; D054414:Chemokine CCL17 / Q000097:blood* / Q000378:metabolism; D054422:Chemokine CCL22 / Q000097:blood* / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D009483:Neuropsychological Tests; D054398:Receptors, CCR4 / Q000378:metabolism
chemical_list: D054414:Chemokine CCL17; D054422:Chemokine CCL22; D054398:Receptors, CCR4