"First Evidence of Immune Response Targeting Brain Cells in Autism"

What would you think if someone told you that if you boosted your immune system you could even prevent Autism Disorders???

Autism is a developmental disorder characterized by difficulties with social interaction,communication, and by restricted and repetitive behavior. 


Is associated with a combination of genetic and environmental factors. Risk factors during pregnancy include certain infections, such as rubella, toxins including valproic acid, alcohol, cocaine, pesticides, lead, and air pollution, fetal growth restriction, and autoimmune diseases.

Back in 2012 the first step was done in a mouse model study that tied the autism-related behaviors with immune changes. Several large epidemiological studies have found a correlation between viral infection during the first trimester of a mother's pregnancy and a higher risk for autism spectrum disorder in her child.

But this time researchers examine hummans brains and found that autism spectrum disorder could be an autoimmune disease.
"We haven't proved causality, but this is one clue in support of the idea that Autism might be an Autoimmune Disorder"...

Investigators typically aim potential treatments at specific pathologies in brain diseases, such as the tangles and plaques that characterize Alzheimer’s disease and the Lewy bodies seen in Parkinson’s. Researchers states that: "Until now, we didn't had a promising target like that in autism"


The Study...

In a paper published in Annals of Neurology, Matthew Anderson, HMS associate professor of pathology at BIDMC, and colleagues, report the presence of cellular features consistent with an immune response targeting specialized brain cells in more than two-thirds of autistic brains analyzed postmortem.

These cellular characteristics that have not previously observed in autism, lend critical new insight into autism’s origins and could pave the way to improved diagnosis and treatment for people with this disorder.

“While further research is needed, determining the neuropathology of autism is an important first step to understanding both its causes and potential treatment” 

Anderson was examining brains when he noticed the presence of perivascular lymphocyte cuffs—an accumulation of immune cells surrounding blood vessels in the brain.

He also noticed mysterious bubbles or blisters that scientists call "blebs" accumulating around these cuffed blood vessels and that these blebs contained debris from a subset of brain cells called astrocytes.

-Perivascular lymphocyte cuffing is a well-known indicator of chronic  
 inflammation in the brain and have not previously linked to autism 
-Lymphocyte cuffs in the brain are telltale signs of viral infections or 
 autoimmune disorders.

But the pattern researchers observed, did not match any previously documented infection or autoimmune disorder of the brain. In the brains that they examined, the cuffs were subtle but distinct. “I’ve seen enough brains to know why you shouldn’t see that,” Anderson said.

To find out if the perivascular lymphocyte cuffs in this sample of autistic brains were linked to autism spectrum disorder, compared 25 brains from donors diagnosed with the disorder to 30 brains from neurotypical brain donors.

These neurotypical control cases were selected to approximate the age range and medical histories of the autism group. Present in more than two-thirds of the autistic brains, perivascular lymphocyte cuffing significantly surpassed that in the control cases.

In a second set of experiments,  determined that the perivascular cuffs were made up of killer T cells, a subset of immune cells responsible for attacking and killing damaged, infected or cancerous cells or normal cells in autoimmune diseases.

With no apparent evidence of viruses known to infect the brain, the presence of these tissue-attacking immune cells throughout the autistic brains suggested one of two scenarios, explained Anderson. Either the T cells are reacting normally to a pathogen such as a virus, or they are reacting abnormally to normal tissue—the definition of an autoimmune disorder.

“With this new research, we haven’t proved causality, but this is one clue in support of the idea that autism might be an autoimmune disorder, just like multiple sclerosis is thought to be,” said Anderson.

In future research, Anderson and colleagues will work to develop a genetically engineered animal model of this T-lymphocyte cuffing neuropathology to conduct studies to determine mechanism as well as cause and effect.

The team also plans to search for biomarkers—a measurable diagnostic signature in patients’ urine, blood or tissues—that may be used to identify these newly documented cellular features in living patients. In turn, these biomarkers could one day assist clinicians in the diagnosis and long-term care of people with autism.

Sources: Harvard.edu
             Sciencedaily.com