New research suggests brains affected by autism show similar signs of inflammation.
Researchers looked at data from 72 autism and control brains and found those affected by the condition exhibited a "ramped-up" immune response, Johns Hopkins Medicine reported.
"There are many different ways of getting autism, but we found that they all have the same downstream effect," said 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."
Researchers are still unsure of the exact causes of autism, and these new findings could bring them one step closer to solving the mystery. Past studies on gene expression and autism have not included enough data to come to a solid conclusion. This is because gene expression testing must be conducted on specific tissue, and brain tissues can only be obtained in autopsies.
In order to get around this problem, the team looked at gene expression in samples from two different tissue banks, comparing those affected with autism and those without the condition. The researchers were able to pinpoint a type of support cell called a microglial cell, which helps protect the brain from invaders such as pathogens. In brains with autism the microglia was perpetually activated with their genes for inflammation 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," said Andrew West, Ph.D., an associate professor of neurology at the University of Alabama at Birmingham who was involved in the study.
The findings suggest a link between autism and inflammation, but researchers do not believe it is the root cause.
"This is a downstream consequence of upstream gene mutation," West said.
In the future the researchers hope to determine whether or not treating the inflammation would help ease some of the symptoms of autism.
The findings were published in a recent edition of the journal Nature Communications.
