Abnormalities in the immune system that imitate those seen with autism spectrum disorders have been connected to the amyloid precursor protein (APP), reports a research team from the University of South Florida’s Department of Psychiatry and the Silver Child Development Center.
A recent study using a mouse model of autism proposes abnormalities in the immune system could be linked to pervasive developmental disorders.
The research proposes that heightened levels of an APP fragment circulating in the blood could explain the abnormalities in immune cell populations and function – both of which are seen in some autism patients. The conclusions of this study were published online in the Journal of the Federation of American Societies for Experimental Biology.
The USF researchers have come to believe that the protein fragment might not only be a biological marker for the disorder but also a new area of research targeted at understanding the physiology of autism.
“Autism affects one in 110 children in the United States today,” said research team leader Jun Tan, MD, PhD, professor of psychiatry and the Robert A. Silver Chair, Rashid Laboratory for Developmental Neurobiology at USF’s Silver Child Development Center. “While there are reports of abnormal T-cell numbers and function in some persons affected with autism, no specific cause has been identified. The disorder is diagnosed by behavioral observation and to date no associated biomarkers have been identified.”
“Not only are there no associated biomarkers, but the prognosis for autism is poor and the costs associated with care are climbing,” said Francisco Fernandez, MD, department chair and head of the Silver Center. “The work of Dr. Tan and his team is a start that may lead to earlier diagnosis and more effective treatments.”
The amyloid precursor protein is usually studied in connection with Alzheimer’s disease.
However, recent studies have shown elevated levels of the particular protein fragment, called, sAPP-α, in the blood of autistic children.
The fragment is a well-known growth factor for nerves, and studies imply that it also plays a role in T-cell immune responses.