Autism spectrum disorders affect one in 59 American children by age eight. With no known quantitative biological features, autism diagnoses are currently based on expert assessments of behavioral symptoms, including impaired social skills and communication, repetitive behaviors and restricted interests.
In a paper published in
Annals of Neurology, Matthew P. Anderson, MD, Ph.D., a physician-scientist at Beth Israel Deaconess Medical Center (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—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," said Anderson, who is Chief of Neuropathology in the Department of Pathology at BIDMC and an Associate Professor of Pathology at Harvard Medical School. "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. Until now, we have not had a promising target like that in autism."
Anderson was examining brains donated to Autism BrainNet, a non-profit tissue bank, when he noticed the presence of perivascular lymphocyte cuffs—an accumulation of immune cells surrounding blood vessels in the
brain. He also noted mysterious bubbles or blisters that scientists call blebs accumulating around these cuffed blood vessels. Anderson and colleagues subsequently found these blebs contained debris from a subset of brain cells called astrocytes.
Not previously linked to autism, perivascular lymphocyte cuffing is a well-known indicator of chronic inflammation in the brain. Lymphocyte cuffs in the brain are telltale signs of viral infections or autoimmune
disorders. But the pattern Anderson observed did not match any previously documented infection or autoimmune disorder of the brain. In the brains Anderson examined, the cuffs were subtle but distinct. "I've seen enough brains to know you shouldn't see that," he said.
Sign up with Google
