Autism spectrum disorders and altered immune function

Autism and autoimmunity have been linked in a number of earlier studies. A paper just published in Research in Autism Spectrum Disorders sheds more light on the role of immune dysregulation in ASDs. The authors state:

"Previous studies have shown that children with autism spectrum disorders (ASDs) have impaired executive function, disordered neural connectivity, and abnormal immunologic function. The present study examined whether these abnormalities were associated."

They compared two groups of seventeen high-functioning (HFA) and 17 low-functioning (LFA) children with ASD, aged 8–17 years, for general intelligence in terms of IQ; executive and non-exective task functions as measured by seven standardized tests; neural connectivity by theta coherence in the anterior and posterior regions; and immunologic function as measured by the level of circulating CD3+ CD8+ suppressor/cytotoxic T lymphocytes in a blood sample. The low-functioning children were notable for immune dysregulation along with disordered EEG connectivity:

"Results on executive function showed that LFA children performed significantly poorer than HFA children as shown on their lower Executive Composite as well as individual executive function scores. However, there was no group difference on the Picture Completion Task. Results on neural connectivity showed that LFA children demonstrated a different pattern of electroencephalography (EEG) coherence from HFA children as shown in the significantly elevated theta coherence in the anterior network, as well as at the left intra-hemispheric (LA-LP) and right-to-left inter-hemisphere (RA-LP) connections of LFA children. In immunologic function, results showed that LFA children had significantly elevated level of suppressor/cytotoxic T lymphocytes (CD3+ CD8+). In addition, the executive dysfunction, disordered neural connectivity, and abnormal immunologic function were found to be associated."

Interested readers can return here for forthcoming posts that illustrate the importance of immune function in a wide range of brain and CNS disorders. Implementation in case management must be individualized on a case by case basis, but no assessment of autism spectrum disorders is complete without carefully investigating a possible autoimmune component. The authors conclude:

"These results provided some initial evidence to support the notion that immunologic factors are associated with neuronal damage, measureable by EEG coherence and manifested as executive dysfunctions."