Novel Blood Biomarker Identified for Autism

Early intervention is the key to the best treatment for autism spectrum disorder (ASD), which affects about 1 in 70 children. Unfortunately, most children are not diagnosed until about age four, when communication and social disabilities become apparent.

Blood biomarkers have been identified that could distinguish the majority of ASD study participants versus a control group of similar age range. In addition, the biomarker was significantly correlated with the level of communication impairment, suggesting that the blood test may give insight into ASD severity.

Scientists at the University of Texas Southwestern Medical Center (Dallas, TX, USA) recruited for an ASD group 74 male subjects with a median age of 5.6 years; 60 males with a median age of 6.3years for a typically developing group (TD), 10 ASD females and 20 TD females. For a control group 53 adult male serum samples were obtained whose median age was 69 years. A fasting blood draw was performed on all ASD and TD subjects.

Since other studies have found abnormalities in the immune systems of autistic children, the scientists set out to search for antibodies in the blood related to ASD. The teams used various techniques to isolate biomarkers. These included peptoid library synthesis, on-bead magnetic screening, peptoid enzyme-linked immunosorbent assay (ELISA), affinity purification of peptoid-binding proteins, gel electrophoresis and Coomassie Blue staining.

The investigators found that found that boys with ASD had significantly reduced levels of a serum immunoglobulin G1 (IgG1) antibody. Investigating further, they analyzed 25 peptoid compounds that bound to IgG1 and zeroed in on one, ASD1, that was 66% accurate in diagnosing ASD. When combined with thyroid stimulating hormone level measurements, the ASD1-binding biomarker was 73% accurate at diagnosis. Girls made up a small ratio of the study group, and the biomarker did not correlate as strongly with ASD diagnosis as with boys.

Dwight German, PhD, a Professor of Psychiatry and senior author of the study said, “Numerous investigators have long sought a biomarker for ASD. The blood biomarker reported here along with others we are testing can represent a useful test with over 80% accuracy in identifying ASD.” The study was published in the June 2016 issue of the journal Scientific Reports.

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University of Texas Southwestern Medical Center