Could autism be diagnosed via a simple blood test?

In a landmark study, scientists from the University of Warwick have developed new blood and urine tests that could identify autism in children.

The team, which included scientists from a range of other academic institutions, found a direct link between ASD (autism spectrum disorder) and damage to proteins in the blood. Specifically, children with ASD were found to have higher levels of an dityrosine, which indicates oxidation, and sugar-modified compounds called “advanced glycation endproducts” in their blood plasma.

Currently, there is no test to identify ASD, which the NHS describes as “a range of similar conditions, including Asperger syndrome, that affect a person’s social interaction, communication, interests and behaviour.” Although symptoms can sometimes be spotted at a very young age, diagnosis can be tricky and normally only happens following a number of assessments by doctors and language and speech therapists. 

The team, whose findings have been published in Molecular Autism, hope that the tests could lead to earlier detection of ASD, so that affected children can receive treatment sooner.

“Our discovery could lead to earlier diagnosis and intervention. We hope the tests will also reveal new causative factors,” said Dr Naila Rabbani, who led the study.

Because the study used a very small sample – 38 children with ASD and 31 without ASD – the team plans to repeat the study, not only to confirm its findings but also to establish whether ASD can be detected even earlier, and whether the future development of the disease can be predicted.

“With further testing we may reveal specific plasma and urinary profiles or “fingerprints” of compounds with damaging modifications. This may help us improve the diagnosis of ASD and point the way to new causes of ASD”, said Rabbani.

However, some experts have warned that we shouldn’t expect to see the Warwick team’s blood test being used in the real world any time soon.“There have been several attempts at developing biomarkers for autism, none of which have been particularly successful,” said Autistica’s Director of Science, Dr James Cusack.  “This attempt is weakened by a small sample size, possible overfitting of data and a lack of comparison groups.”

“This study does not tell us how effectively this measure can differentiate between autism and other neurodevelopmental or mental health conditions such as ADHD and anxiety…The design of the study itself is sufficiently robust as an exploratory experimental study, but the results cannot be used to propose a potential new diagnostic measure at this stage.”