Estimated to afflict 1 in 88 children, scientists have made extraordinary advances in understanding the causes of autism. But remarkably little of this understanding has seeped into popular awareness, whose main focus more often than not are vaccines.
Immune dysregulation is what scientists are calling it. In a perfect world, your immune system should perform immediately and forcefully when needed and then return to its calm state when finished. In order to do this, your immune system requires a balance of pro and anti inflammatory muscles.
In people with autism, the balance of these muscles fails. The signals needed for anti inflammatory muscles are dominated by the inflammatory ones causing discerning autistic symptoms.
The autistic brain shows more evidence of dysregulation than any other. Neurons that are maintained through certain cells become enlarged from constant activation.
These findings are important for many reasons, but perhaps the most significant is that they provide evidence of an abnormal, persisting biological process. That means that there is finally a healing goal for a disorder ascertained by behavioral precedent like social impairments, difficulty communicating and repetitive behaviors.
Scientists decided to start with the womb. A study from Denmark covering two decades of births indicates that infection during pregnancy increases the risk of autism in the child. Hospitalization for a viral infection during the first trimester of pregnancy triples the odds.A bacterial infection such as a urinary tract infection, increases the chances by 40 percent if infected during the second trimester.
It doesn’t seem that infection itself is to blame for damage to the fetus, but more likely to be the mother’s immune system’s attempt to fight off the virus.
Better clues to the causes of the autism phenomenon come from equal “epidemics.” The predominance of inflammatory diseases in general has increased significantly in the past 60 years. As a group, they include asthma, now estimated to afflict 1 in 10 children — at least double the prevalence of 1980 — and autoimmune disorders which afflict 1 in 20.
Both are linked to autism, especially in the mother. One large study in Denmark, including nearly 700,000 births over a decade, found that a mother’s rheumatoid arthritis, a degenerative disease of the joints, raised a child’s risk of autism by 80 percent. An inflammatory disease, celiac, prompted by proteins in wheat and other grains, increased it 350%. Variants in genes associated with autoimmune disease also increase the risk of autism, especially when they occur in the mother.
But there are still other paths to the disorder. Mothers in their second trimester with asthma or allergies increases her child’s chance of having autism.
There is much debate surrounding the autism phenomenon. Indicative criteria have changed repeatedly, and awareness has increased. Scientists have continuously observed that people living in environments that resemble our past, full of microbes and parasites, don’t suffer from inflammatory diseases as often as we do.
Autism also follows this pattern generally. It seems to be less accepted in the developing world. Usually, epidemiologists fault lack of diagnosis for the apparent absence. An insufficiency of expertise in the disorder gives a false impression of deficiency. Yet at least one Western doctor who specializes in autism has clearly noted that, in a Cambodian population abundant with parasites and acute infections, autism was nearly absent.
In environments that resemble the world of yesteryear, the immune system is much less prone to diseases of dysregulation.
Generally, the scientists working on autism and inflammation aren’t aware of this — or don’t let on if they do. But Kevin Becker, a geneticist at the National Institutes of Health, has pointed out that autism and asthma follow similar epidemiological patterns. They’re both more common in urban areas than rural; firstborns seem to be at greater risk; they excessively afflict young boys.
In the context of allergic disease, the hygiene hypothesis — that we suffer from microbial withdrawal — has long been invoked to explain these patterns. Dr. Becker argues that it should apply to autism as well. (Why are male fetuses more prone than female?)
More recently at Duke University, William Parker has chimed in. He is not an autism expert, but his work focuses on the immune system and its role in biology and disease, so he’s specifically qualified to point out the following: the immune system we consider normal is actually an evolutionary oddity.
He began comparing wild sewer rats with clean lab rats a few years ago. They were, in his words, “completely different organisms.” Wild rats tightly controlled inflammation. Not so the lab rats. Why? The wild rodents were overrun with parasites. Parasites are famous for restricting inflammation.
Dr. Parker and many others think that we are biologically dependent on the immune elimination provided by these hangers-on and that their removal has left us prone to inflammation. “We were willing to put up with hay fever, even some autoimmune disease,” he said recently. “But autism? That’s it! You’ve got to stop this insanity.”
What does stopping this consist of? Fix the maternal dysregulation, and you’ve most likely prevented autism. That’s the lesson from rodent experiments. Swiss scientists, in an experiment, created a lineage of mice with a genetically reinforced anti-inflammatory signal. Then the scientists disturbed the pregnant mice. The babies emerged fine — no behavioral problems. The take-away: Control inflammation during pregnancy, and it shouldn’t interfere with fetal brain development.
Practically speaking, this seems beyond improbable. And yet, a trial is under way at the Montefiore Medical Center and the Albert Einstein College of Medicine testing a medicalized parasite called Trichuris suis in autistic adults.
First used medically to treat inflammatory bowel disease, the whipworm, which is mostly found in pigs, has anecdotally shown benefit in autistic children.
If you spend enough time working through through the science, Dr. Parker’s idea not only fails to seem brazen, but also seems inevitable.
Since ancient time, a very specific community of organisms — microbes, parasites, some viruses — has aggregated to form the human superorganism. Mounds of evidence suggest that our immune system anticipates these inputs and that, when they go missing, the organism comes unhinged.
Future doctors will need to correct the postmodern tendency toward immune dysregulation. Evolution has provided us with a road map: the original build up pattern of the superorganism. Preventative medicine will need, by strange necessity, to emulate the patterns from deep in our past.