title: In search of cellular immunophenotypes in the blood of children with autism.
abstract: BACKGROUND
  Autism is a neurodevelopmental disorder characterized by impairments in social behavior, communication difficulties and the occurrence of repetitive or stereotyped behaviors. There has been substantial evidence for dysregulation of the immune system in autism.
  
  
  METHODS
  We evaluated differences in the number and phenotype of circulating blood cells in young children with autism (n = 70) compared with age-matched controls (n = 35). Children with a confirmed diagnosis of autism (4-6 years of age) were further subdivided into low (IQ<68, n = 35) or high functioning (IQ ≥ 68, n = 35) groups. Age- and gender-matched typically developing children constituted the control group. Six hundred and forty four primary and secondary variables, including cell counts and the abundance of cell surface antigens, were assessed using microvolume laser scanning cytometry.
  
  
  RESULTS
  There were multiple differences in immune cell populations between the autism and control groups. The absolute number of B cells per volume of blood was over 20% higher for children with autism and the absolute number of NK cells was about 40% higher. Neither of these variables showed significant difference between the low and high functioning autism groups. While the absolute number of T cells was not different across groups, a number of cellular activation markers, including HLA-DR and CD26 on T cells, and CD38 on B cells, were significantly higher in the autism group compared to controls.
  
  
  CONCLUSIONS
  These results support previous findings that immune dysfunction may occur in some children with autism. Further evaluation of the nature of the dysfunction and how it may play a role in the etiology of autism or in facets of autism neuropathology and/or behavior are needed.
authors.affiliation: Department of Medical Microbiology and Immunology, University of California Davis, Davis, California, United States of America.
authors.forename: Paul
authors.initials: P
authors.lastname: Ashwood
authors.forename: Blythe A
authors.initials: BA
authors.lastname: Corbett
authors.forename: Aaron
authors.initials: A
authors.lastname: Kantor
authors.forename: Howard
authors.initials: H
authors.lastname: Schulman
authors.forename: Judy
authors.initials: J
authors.lastname: Van de Water
authors.forename: David G
authors.initials: DG
authors.lastname: Amaral
mesh_terms: D001321:Autistic Disorder / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D016130:Immunophenotyping / Q000379:methods*; D008297:Male; D013601:T-Lymphocytes / Q000276:immunology