Maternal Antibodies in Pregnancy Indicate Autism Risk

The transfer of maternal IgG (Immunoglobulin G) antibodies during pregnancy is a risk factor for autism, and at some point, a prenatal test and treatment could prevent the disorder for some children.

Antibodies in the blood of mothers of children with autism bind to fetal brain cells, potentially interrupting healthy brain development. The reaction was most common in mothers of children with the regressive form of autism, which occurs when a period of typical development is followed by loss of social and/or language skills.

Dr. Judy Van de Water, professor of rheumatology, allergy, and clinical immunology at the University of California (UC) Davis MIND Institute and Center for Children's Environmental Health (Sacramento, CA, USA), and her team took blood samples from 123 mothers--61 whose children had autism and 62 whose children were developing normally. They isolated IgG antibodies from the samples then exposed the antibody to fetal brain tissue by Western blot analysis, which detects antibody reactivity to proteins. The outcome revealed a highly specific reactivity pattern to two fetal brain proteins in seven of the 61 samples from the autism group, six of which were from mothers of children who had regressive autism. None of the IgG samples from mothers in the control group produced this same result.

IgG antibodies are responsible for long-term immune system responses to infection, but they can also contribute to autoimmune diseases such as arthritis, multiple sclerosis, and lupus. IgG also crosses the placenta in order to provide key immune system protectants to a growing fetus and newborn child, which is a key reason why Prof. Van de Water decided to investigate the role of IgG as a potential factor in autism.

"This is one of the first studies to identify immunological factors in mothers that could be linked to autism in the very earliest stages of life,” said Prof. Van de Water. "We are also optimistic that in the future a prenatal test and therapeutic intervention preventing IgG exposure during pregnancy could protect some children from ever getting autism.”

The study appeared in the March 2008 issue of the journal Neurotoxicology.


Related Links:
University of California Davis MIND Institute