In search of cellular immunophenotypes in the blood of children with autism

Background

Autism is a neurodevelopmental disorder characterized by impairments insocial behavior, communication difficulties and the occurrence of repetitiveor stereotyped behaviors. There has been substantial evidence fordysregulation of the immune system in autism.

Methods

We evaluated differences in the number and phenotype of circulating bloodcells in young children with autism (n = 70) comparedwith age-matched controls (n = 35). Children with aconfirmed diagnosis of autism (4–6 years of age) were furthersubdivided into low (IQ<68, n = 35) or highfunctioning (IQ≥68, n = 35) groups. Age- andgender-matched typically developing children constituted the control group.Six hundred and forty four primary and secondary variables, including cellcounts and the abundance of cell surface antigens, were assessed usingmicrovolume laser scanning cytometry.

Results

There were multiple differences in immune cell populations between the autismand control groups. The absolute number of B cells per volume of blood wasover 20% higher for children with autism and the absolute number ofNK cells was about 40% higher. Neither of these variables showedsignificant difference between the low and high functioning autism groups.While the absolute number of T cells was not different across groups, anumber of cellular activation markers, including HLA-DR and CD26 on T cells,and CD38 on B cells, were significantly higher in the autism group comparedto controls.

Conclusions

These results support previous findings that immune dysfunction may occur insome children with autism. Further evaluation of the nature of thedysfunction and how it may play a role in the etiology of autism or infacets of autism neuropathology and/or behavior are needed.