Brain inflammation a hallmark of autism, large-scale analysis shows

Quinn, an autistic boy, and the line of toys he made before falling asleep. Repeatedly stacking or lining up objects is a behavior commonly associated with autism. Credit: Wikipedia.

While many different combinations of genetic traits can cause autism, brains affected by autism share a pattern of ramped-up immune responses, an analysis of data from autopsied human brains reveals. The study, a collaborative effort between Johns Hopkins and the University of Alabama at Birmingham, included data from 72 autism and control brains. It will be published online Dec. 10 in the journal Nature Communications.

"There are many different ways of getting , but we found that they all have the same downstream effect," says Dan Arking, Ph.D. , an associate professor in the McKusick-Nathans Institute for Genetic Medicine at the Johns Hopkins University School of Medicine. "What we don't know is whether this immune response is making things better in the short term and worse in the long term."

The causes of autism, also known as , remain largely unknown and are a frequent research topic for geneticists and neuroscientists. But Arking had noticed that for autism, studies of whether and how much genes were being used—known as gene expression—had thus far involved too little data to draw many useful conclusions. That's because unlike a genetic test, which can be done using nearly any cells in the body, gene expression testing has to be performed on the specific tissue of interest—in this case, brains that could only be obtained through autopsies.

To combat this problem, Arking and his colleagues analyzed gene expression in samples from two different tissue banks, comparing gene expression in people with autism to that in controls without the condition. All told, they analyzed data from 104 brain samples from 72 individuals—the largest data set so far for a study of in autism.

Previous studies had identified autism-associated abnormalities in cells that support neurons in the brain and spinal cord. In this study, Arking says, the research team was able to narrow in on a specific type of support cell known as a microglial cell, which polices the for pathogens and other threats. In the autism brains, the microglia appeared to be perpetually activated, with their genes for inflammation responses turned on. "This type of inflammation is not well understood, but it highlights the lack of current understanding about how innate immunity controls neural circuits," says Andrew West, Ph.D., an associate professor of neurology at the University of Alabama at Birmingham who was involved in the study.

Arking notes that, given the known genetic contributors to autism, inflammation is unlikely to be its root cause. Rather, he says, "This is a downstream consequence of upstream gene mutation." The next step, he says, would be to find out whether treating the inflammation could ameliorate symptoms of autism.

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Journal information: Nature Communications

Citation: Brain inflammation a hallmark of autism, large-scale analysis shows (2014, December 10) retrieved 18 August 2019 from
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Dec 10, 2014
Absolutely. Brain inflammation is clearly listed in the side effects on the manufacturer's inserts to vaccines. Since the link has now been proven in over 80 studies, why are we still injecting our perfect babies with toxins to "prevent" (said tongue-in-cheek) statistically harmless and necessary childhood diseases?

Dec 10, 2014
Absolutely True! Sandra. As an RN I have known this from the very start. What most people don't know is that there is an historically better way to safely prevent and treat in all epidemics. Vaccines intentionally cause a huge inflammation of the system including the vagus nerve which innervates the brain as well as the gut. There is a 150 year proven history of homeopathic MD's in this country who have documented how to use this system. Measles, mumps, chickenpox all necessary to clear out inherited taints from the body and can all be made safe with this system of medicine once taught in our U.S. Medical Schools and used by our MD's.Injecting preservatives, formaldehyde and dead viruses directly into blood streams of infants breaks down their immune system due to intended inflammation using these chemicals.

Dec 10, 2014
yep I agree vaccines, specifically the adjuvants used in them are a likely cause of autoimmunity leading to inflammation, along with potential food allergies such as dairy and wheat which have also been linked to the condition.

Dec 10, 2014
One can hope that honesty would take hold, and all sources of inflammation will AT LAST be recognized: Radiofrequency radiation, which has been allowed to proliferate, causes developmental and ongoing brain damage at very low levels (lower than cell phone emissions), especially in the fetus. See the MD Symposium at C4ST, BabySafe Project and the 2012 BioInitiative Report.
See also Dr. Leif Salford's presentation about damage to the blood brain barrier from brief, low RF exposures. (youtube)

When will medical people (beyond environmental medicine) acknowledge the fact that wireless radiation as allowed is toxic, especially to children? In the past, doctors would advertise cigarette brands.. Same with wireless, too much fun and convenience at this moment. WHO WILL PAY? fetuses, children, the ill and elderly. So much for a moral society.

Dec 11, 2014
Well, science has discovered there is a system piggy backed on blood vessels that uses spinal fluid to remove the damaged cells, the garbage system as science describes it. So maybe it is the defective cleaning system that permits this level of inflammation?
Our culture has proved itself unable to stop damage so one supposes that it is this sifting of factors is to be allowed to run enabling the less damaged genetic individuals to be identified . Maybe life is just one big challenge test for the genetic adaptation.

Dec 12, 2014
I don't like to always be "that guy" who is always touting medical uses for MJ... but... I'm going to be that guy today...

THC and CBD cannabinoids in MJ have been shown to reduce inflammation, including brain inflammation... Including the claim in the US Government's patent for CBD and its neuroprotective properties.

Just one more potentially ground breaking use for the plant and/or the compounds found within...

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