In a study published in the online journal PLoS ONE, a research group from the Hamamatsu University School of Medicine, Hamamatsu, Japan reports the presence of high levels of several pro-inflammatory cytokines in male (≥6 years old) subjects with autism spectrum disorder (ASD).
ASD include autistic disorder, Asperger’s disorder and pervasive developmental disorder.
A dysregulation of the immune system may be implicated in the pathophysiology of ASD. Increased levels of some inflammatory cytokines in peripheral samples such as serum or plasma of patients with ASD were reported, but previous data appear to be inconsistent, most likely due to variations in the experimental designs.
Recent advances in multiplex technologies have enabled measurement of multiple analytes simultaneously.
In the PLoS ONE study, Katsuaki Suzuki and colleagues have used a multiplex assay, and demonstrate that plasma levels of IL-1beta, IL-1RA, IL-5, IL-8, IL-12(p70), IL-13, IL-17 and GRO-α in the high-functioning male subjects with ASD were significantly higher than those of matched control subjects.
The elevated plasma levels of IL-12(p70) substantiate previous data in children with autism and adults with Asperger’s syndrome.
The increased levels of IL-17 reported in this study are also validated by recent research showing that IL-17A levels correlate with the severity of autism. Importantly, it appears that IL-17 interfere with the normal brain development in a mouse model of autism.
Suzuki et al. also discuss that the increased IL-8 and GRO-α plasma levels might have resulted from IL-17 secretion by Th17 cells activated in response to subclinical infections in epithelial or endothelial cells in the subjects with ASD.
The authors suggest that the elevation of these cytokines may indicate an abnormal steady-state immune response in subjects with ASD, and that such a multiplex analysis of cytokines may serve as one of the biological trait markers for the disorder.
SOURCE: PLoS ONE 2011, 6: e20470