UC Davis MIND Institute researchers have identified the specific antibodies that target fetal brain proteins in the blood of a subset of women whose children are diagnosed with autism. The finding is the first to pinpoint a specific risk factor for a significant subset of autism cases, as well as a biomarker for drug development and early diagnosis. The researchers have named autism related to these antibodies “Maternal Autoantibody-Related," or MAR autism.
The study found that the mothers of children with autism were more than 21 times as likely to have the specific MAR antibodies in their systems that reacted with fetal brain proteins, or antigens, than were the mothers of children who did not have autism. In fact, specific combinations of MAR antibodies were not found in the blood of mothers whose children were typically developing.
The research, "Autism-specific maternal autoantibodies recognize critical proteins in developing brain," is published online today in Translational Psychiatry, a Nature journal.
The study was led by principal investigator and immunologist Judy Van de Water, a researcher affiliated with the MIND Institute. Earlier studies by Van de Water and her colleagues found that women with certain antibodies in their bloodstreams are at greater risk of having a child with autism and that their children exhibited more severe language delays, irritability and self-injurious behaviors than did the autistic children of mothers whose blood did not have the antibodies.
“Now we will be able to better determine the role of each protein in brain development,” said Van de Water, professor of internal medicine. “We hope that, one day, we can tell a mother more precisely what her antibody profile means for her child, then target interventions more effectively.”
To identify the exact antigens targeted by the mothers’ antibodies, Van de Water and her colleagues conducted the research in Northern California using blood samples from 246 mothers of children with autism and of a control group of 149 mothers of children without autism to examine their reactivity with the candidate antigens.
Seven antigens were significantly more reactive to the blood of mothers of children with autism than to that of the control mothers. The study found that the mothers with antibodies that reacted with any one of these antigens, either individually or in combination with other antigens, were more than three times as likely to have a child with autism spectrum disorder.
Several combinations of antibodies in the blood from mothers of children with autism were not found in the control mothers’ blood. Nearly 23 percent of mothers of children with autism had certain combinations of autoantibodies against the target antigens, compared with less than 1 percent of mothers of children without the disorder.