April 25, 2009

Mother’s Immune Response May Play Role In Autism

In ground-breaking new research conducted on mice, scientists have observed that the antibodies produced by pregnant mothers are transmitted to the fetus and may cause inflammation in the child's brain.

Previous research has demonstrated that mothers of autistic children develop a specialized immune response to the fetus, including the production of an antibody that can specifically attack the brain, eventually leading to autism.

Dr. Harvey Singer and his colleagues at the Johns Hopkins Hospital in Baltimore, Maryland extracted the novel antibodies from human mothers of autistic children and injected them into pregnant mice.  Two separate control groups of pregnant mice were either injected with the antibodies from the mothers of non-autistic children or were given nothing at all.

The researchers observed that the mice pups born from the mothers who had received the autistic antibodies exhibited symptoms resembling that of human autism.  The affected mice exhibited increased levels of anxiety, anti-social behavior, hyperactivity, a tendency to spend more time in enclosed spaces and were easily startled by loud noises.

The study also noted that autistic symptoms became increasingly more pronounced and easily observable as the mice matured from infancy to adulthood "“ a pattern strikingly similar the development of autism in humans.

"Comparing mice to humans is tricky," warned Singer in a statement to the media.  "We should be cautious anytime we do so; but our findings strongly suggest that the behaviors we observed in the offspring of mice injected with fetal brain antibodies from human mothers did behave in a manner that mimics some behaviors seen in people with autism."

"Autism is a complex disorder and it would be naïve to assume there's a single mechanism that can cause it," he added.  "It's most likely the cumulative effect of several factors, including genes, metabolism, and the environment.  We believe we have identified one of those factors."

In the U.S., the prevalence of autism and autism-related disorders like Asperger syndrome and PDD-NOS is about 6 per 1,000 children, with incidences in males being four-fold higher than in females. The number of people known to have autism has increased dramatically since the 1980s, due largely to changes in diagnostic practice.  The question of whether actual prevalence has increased in recent years remains an issue of intense debate among experts in the field.


On the Net: