Diagnosing autism spectrum disorder can be a complicated process, requiring multiple behavioral and developmental analyses, although research conducted by a team of researchers from the UK and Italy suggest it may be possible to develop urine and blood tests for autism spectrum disorder in the not too distant future.
Currently there are approximately 3.5 million people in the United States that have autism spectrum disorders, and 700,000 people diagnosed with ASD in the United Kingdom, although many individuals live with the disorder without having it diagnosed. A blood test could help doctors diagnose ASD much more easily, even in children as young as 2 years old.
Currently there are no such tests available to doctors, although levels of proteotoxic biomarkers could potentially be used to aid diagnosis. Researchers from University of Warwick and University of Bologna conducted a small-scale study to test whether the presence of these biomarkers in the blood and urine could be used as a diagnostic tool.
The researchers conducted tests on 38 children between 5 and 12 years who had been diagnosed with autism spectrum disorder using conventional techniques, and 31 children in the same age range who did not have the condition.
The researchers analyzed levels of the oxidation marker ditryosine and plasma protein glycation end-products. The researchers found that children diagnosed as suffering from ASD had higher levels of protein damage than those without the disorder. The glycation end-products Nε-carboxymethyl-lysine (CML) and Nω-carboxymethylarginine (CMA) were also elevated in children diagnosed with ASD.
The urine tests revealed children diagnosed with ASD had higher levels of oxidation free adducts, alpha-aminoadipic semialdehyde and glutamic semialdehyde.
The researchers concluded that the changes to plasma AGE’s was likely indicative of dysfunctional metabolism of dicarbonyl metabolite precursors of the AGEs: Glyoxal and 3-deoxyglucosone. The researchers also explained, “Decreased renal clearance of arginine and CMA in ASD is indicative of increased arginine transporter activity which may be a surrogate marker of disturbance of neuronal availability of amino acids.
The findings of the researchers could pave the way to the development of urine and blood tests for autism spectrum disorder, although the researchers were cautious, and said considerable research is required before tests could be made clinically available.
The research is detailed in the paper – Advanced glycation endproducts, dityrosine and arginine transporter dysfunction in autism – a source of biomarkers for clinical diagnosis – which was recently published in the journal Molecular Autism.