While science has yet to pinpoint the exact cause of autism, a new study reveals that the brains of people with the disorder share a common pattern of inflammation from an overactive immune response.
Johns Hopkins and University of Alabama at Birmingham researchers analyzed data from autopsied brains of 72 people, 32 of whom had autism. In the brains of people with autism, they found genes for inflammation permanently activated in certain cells. The study, published in the online journal Nature Communications on Dec. 10, is the largest so far of gene expression in autism.
"There are many different ways of getting autism, but we found that they all have the same downstream effect," Dan Arking, Ph.D., an associate professor in the McKusick-Nathans Institute for Genetic Medicine at the Johns Hopkins University School of Medicine said in a statement. "What we don't know is whether this immune response is making things better in the short term and worse in the long term."
Inflammation is not likely a root cause of autism, but a consequence of a gene mutation, Arking stressed. To better understand inflammation's effects, researchers will want to find out whether treating it makes autism symptoms any better, he said.
Autism is the most severe of a range of neurological and developmental disorders classified as autism spectrum disorder (ASD). The most common symptom of autism is difficulty with social interactions, such as discomfort with eye contact and trouble interpreting social cues. Although researchers have identified certain genes and areas of the brain associated with the disorder, it's likely that environment also plays a role in causing autism.
"This type of inflammation is not well understood," Andrew West, Ph.D., an associate professor of neurology at the University of Alabama at Birmingham who was involved in the study said in a statement. He added that the current findings highlight how much we don't know about the way our immune systems affect brain activity.