Lead investigator Dr. Harvey Singer of The Hopkins Children's Center in Baltimore says the research suggests that the mother's immune system may be yet another factor or a trigger in those predisposed to autism.

The research team used a technique called immunoblotting, or Western blot technology, in which antibodies derived from blood samples are exposed to adult and fetal brain tissue to check whether the antibodies recognize and react against specific brain proteins.

The researchers compared the antibody-brain interaction in samples obtained from 100 mothers of autistic children and 100 mothers of children without autism. The researchers found stronger reactivity or more areas of reactivity between antibodies and brain proteins in about 40 percent of the samples obtained from the mothers of autistic children.

The study, published in the Journal of Neuroimmunology, says the presence of maternal antibodies was associated with developmental regression in children.

The investigators say further studies are needed to confirm the finding.