Autism is a complex disorder with numerous suspected causes that include genetic abnormalities, exposure to certain prescription drugs during pregnancy, a children born to older parents. At the heart of it autism is considered to be a problem of abnormal brain development that may result in an inability to prune unnecessary neurons from the brain. What we don’t know is why the brain develops abnormally and if there is anything we can do to intervene in this process. There currently exists no cure for autism and treatments are focused on behavioural therapy to increase the quality of life and functional state of the individual. A hypothesis that has become the focus of some autism researchers of late is known as the cell danger response. The cell danger response is an evolutionary conserved response that cells undergo when exposed to chemical, physical, or biological threats in their environment. It is meant to protect the cells and causes them to seal up their membranes, stop interacting with their neighbours, and essentially shut down until the danger has passed. Normally this allows the cells to heal themselves, get rid of the danger, and continue on as normal. Unfortunately, in situations where this response is not turned off the cell stays in this protective state and the healing process cannot finish. It is thought that this cell danger response plays a role in many autoimmune disorders including: heart disease, cancer, autoimmune disorders, and chronic fatigue syndrome. Now a team of researchers from the University of California San Diego set out to determine if this process may play a role in Autism and if it could be targeted for future treatments.
This small study enrolled 10 males between the ages of 5 and 14 years old with diagnosed autism and put them into two treatment arms. They were matched by age, IQ, and autism severity. The first group (5 of the subjects) were given a placebo intravenous (IV) injection of saline and the second group a single IV injection of a drug called Suramin. Suramin is an older drug synthesized in 1916 and used to treat African sleeping sickness. It is on the WHO list of essential medications and works by blocking the signalling of an important danger signal in cells called ATP. ATP is the energy molecule of the cells but when it is released from damaged or dying cells it signals other cells to take cover. The researchers thought that if the cell danger response is important in autism then blocking the action of ATP may provide some relief from the disease. The researchers primarily measured changes in the ADOS-2 score (a measure of autism severity) in addition to changes in other measures related to quality of life. 6 weeks after the injection, the males who received Suramin had a significant improvement in their autism ADOS scores. Importantly, the males who received Suramin had a greater benefit from behavioural therapies like speech therapy, occupational therapy, and some were even seen playing games with other children. The results were however temporary and disappeared after a few weeks. Additionally, there were some side effects from the treatment including a rash at the injection site.
It is important to note that this small trial was not set up to determine if Suramin or a drug life it could be used to treat autism. It was set up to be a proof of concept to understand the role of cell danger response in autism. A larger study with a more diverse group of subjects is needed to determine if this type of treatment will be useful in managing autism. Importantly, this research also provides us with an initial understanding of the processes going on inside the brain of someone with autism.
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