BUDAPEST, HUNGARY — Children with autism spectrum disorders appear to have immune responses different from those of healthy children, according to data presented at the 4th International Congress on Autoimmunity.
“There is evidence now for an immune dysregulation in children with autism, compared with children in the general population,” said Paul Ashwood, Ph.D., of the University of California, Davis.
In a study of 31 children with autism spectrum disorders (ASD) and 19 typically developing control children aged 2–5 years, the children with ASD had abnormal levels of several cytokines in response to stimulation with three antigens, compared with the control children.
The study adds weight to the idea that autism has an immune component. There are several previous reports of both increased autoimmunity and immune response deficits in children with ASD. “However, a lot of these reports are conflicting, and there is no consensus so far,” Dr. Ashwood said.
In this study, Dr. Ashwood and colleagues isolated and stimulated peripheral blood mononuclear cells for 48 hours with phytohemagglutinin, lipopolysaccharide, and vaccine antigens from tetanus and MMR. Analysis was performed for 18 cytokines. At baseline, cytokine levels were similar in the children with ASD and the control children.
Following stimulation with phytohemagglutinin, the children with ASD had statistically significantly lower levels of IL-2, IL-6, IL-10, and IL-12 than the control children. There was also a trend toward higher levels of IL-13 and granulocyte macrophage-colony stimulating factor—which stimulates the precursor cells of granulocytes, macrophages, and eosinophils—among the children with ASD than the control children.
A similar pattern was seen after stimulation with lipopolysaccharide. Children with ASD had lower levels of IL-12 and a slight increase in granulocyte macro-phage-colony stimulating factor, compared with the control children.
Stimulation with tetanus antigens resulted in lower levels of IFN-γ, IL-1-β, IL-12, and granulocyte macrophage-colony stimulating factor in the children with ASD, compared to the control children.
Although there was no difference after stimulation with MMR vaccine antigens the researchers are planning to investigate the response to individual components of the MMR vaccine.