About Autism

Autism

Are there stem cell therapies available for autism

Currently, there are no Health Canada or U.S. FDA approved stem cell therapies for treating autism. Patients who are researching their options may come across companies with Web sites or materials that say otherwise and offer fee-based stem cell treatments for curing this disorder. Many of these claims are not supported by sound scientific evidence and patients considering these therapies are encouraged to review some of the links below before making crucial decisions about their own treatment plan.

For more about stem cell clinical trials for autism click here. (For printed version: http://1.usa.gov/1CvOyCe)

How close are we? What do we know about autism?

  • Autism is the name used to describe a spectrum of neurodevelopmental disorders that negatively affect brain development and cause life-long deficits in communication, social and behavioral skills.
  • There are four disorders that fall under the unified heading of autism spectrum disorder (ASD): autism (also referred to as classical autism), Asperger’s disorder, childhood disintegrative disorder, and pervasive developmental disorder not otherwise specified.
  • Children with autism seem normal at birth, but within the first 36 months symptoms start to appear. Boys are four times more susceptible than girls.
  • There is no single test to detect autism. Instead, health professionals use physical examinations, personal histories, clinical assessment tools, and possibly genetic testing to make a positive diagnosis.
  • The precise cause of ASD remains a mystery but mounting evidence points to both environmental and genetic factors.
  • The risk of inheriting ASD is 37-90% but there are also many mutations associated with ASD that may be present in a family member for the first time. Scientists have identified chromosomal abnormalities and single gene disorders that share symptoms with ASD, and hundreds of ASD-linked genes that they think might confer susceptibility.
  • Researchers are trying to understand how ASD-linked genes work. Some of the genes are known to connect neurons in the brain, and others are involved in the immune system. One theory is that the brain may develop abnormally if ASD-linked genes are active at the wrong time and place as the fetus develops.
  • Treatments can be behavioral, nutritional and pharmacological. Behavioral interventions and social skills training appear to provide the most benefit but they are not able to correct all the symptoms, so drugs are also prescribed.

How can stem cells play a part?

At present, the field isn’t ready to use stem cells as a source of neurons for transplantation into patients with autism. Instead, stem cells are being used to create models of autism for the purpose of testing the effects of possible new drugs. Scientists are also investigating how the immune system and inflammation are involved in the development of ASD, and whether stem cells could help play a role by dampening the immune system in patients.

Are there lots of groups working on developing a stem cell therapy?

There are many research teams around the globe working to understand how stem cells could be applied to autism. Collectively, these groups have identified making human models of autism a priority because animal models do not entirely mimic autism as it unfolds in humans.

One of the challenges is finding a good source of neurons for the purpose of creating laboratory models. This is not so simple because it’s not possible to remove neurons from a living person. This is where induced pluripotent stem (iPS) cells may be able to help. Their discovery in 2006 by 2013 Nobel Prize winner Dr. Shinya Yamanaka was nothing short of revolutionary. Dr. Yamanaka managed to turn back the clock on adult skin cells and reprogram (induce) them to a more youthful state. The cells are called ‘pluripotent’ because they are no longer locked into making only one type of cell but instead can make a variety of different types of cells, including neurons. The iPS cells made from the skin of people with autism can be grown into neurons for laboratory models.

The road to finding a stem cell therapy for autism is paved with many challenges that will take time to overcome, but researchers are learning a great deal from investigating autism spectrum disorders and disorders that share characteristics with autism, such as Rett syndrome, Fragile X, and Timothy syndrome. As the collective results shed light on possible mechanisms of autism, they also underscore the uniqueness of autism from person to person and the challenges of capturing the wide spectrum of autism in human models.

What research is underway?

The direct clinical application of neurons made from iPS technology is still many years away but scientists are putting this technology to good use by trying to make banks of disease-specific iPS cell lines (from mice and humans) to study disease changes and to use for drug testing.  One of the big challenges will be to figure out how to categorize the lines given the tremendous variation among patients.

As yet there are few published accounts of iPS cell lines made from ASD patients. One research team accomplished this by using skin cells from the hair shaft of patients with a specific mutation associated with ASD. Another group made ASD-specific iPS cells derived from white blood cells collected in the peripheral blood of patients with ASD – and then went on to grow them into neurons that could produce an important neurotransmitter. As the number of ASD-specific iPS lines grow, researchers will be working out the conditions to turn them into various populations of neurons so that they can study changes at the neuronal level that describe ASD.

Scientists are also learning about autism by making iPS cell lines from people who display autistic characteristics, as is the case for those with Rett syndrome, Fragile X, and Timothy syndrome. Screening candidate drugs against these lines is underway and has already yielded some interesting results leading to a small clinical trial testing the safety of a growth factor called IGF-1 in six girls with Rett syndrome. Although the results are promising, larger trials with more patient subgroups will be needed to judge the effectiveness of this therapy.

Because there is clear evidence that hematopoietic stem cells and cord blood stem cells can dampen the immune system in other diseases, researchers are in the process of assessing whether they can do the same for autism. Various immune disorders are known to be associated with autism, including immune deficiencies, autoimmunity, allergy, and over-activation of certain immune cell populations. However, the way in which the immune system is involved is not clear. One theory is that early inflammation, possibly even starting in the womb, might be an important contributing factor.

The wealth of information generated from labs around the globe is converging to help with the transition from basic research to the clinic, but researchers are not rushing ahead with clinical trials. Instead, they are proceeding with great caution and agree that the research priority should be to better understand the mechanisms underlying the function of stem cells and the biology of autism. They will mine that information to create better models in which to test various stem cells and drug therapies for benefits before translating the information into clinical trials.

Further reading on autism

Readers may wish to peruse the recommended sites and below for more information about autism and the possible future applications of stem cells to treat this disease.

NIH Autism Fact Sheets
Autism Canada
Autism Ontario
Autism Speaks Canada

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