The finding may have implications for the cause and treatment of gastrointestinal troubles that often accompany autism spectrum disorders. Diets excluding gluten have become popular in the autism community, but the effectiveness of such diets has not been confirmed.
However, according to the new study, "there appears to be an increased immune reactivity to gluten in children with autism, which is associated with gastrointestinal symptoms," said lead researcher Armin Alaedini, an assistant professor of medical sciences at Columbia University Medical Center in New York City.
The study did not find any link between autism and celiac disease, an autoimmune disorder that is triggered by gluten.
Gluten is found in many wheat and related grain products.
In the study, Alaedini's team reviewed the medical records and blood samples of 140 children, 37 of whom had autism. Researchers tested the blood samples for antibodies to a marker of celiac disease and antibodies to gliadin, a marker of gluten. In addition, patients also were tested for genes associated with celiac disease.
Alaedini stressed that the study is preliminary and "the increased antibody response to gluten [found among patients] does not necessarily indicate sensitivity to gluten or any disease-causing role for the antibodies in the context of autism."
Instead, the higher levels of antibodies to gluten could point to immune and/or intestinal abnormalities in the affected children, he said.
More research into the immune response of people with autism to gluten might bring clues to the condition or highlight "a subset of patients that would respond to certain treatment strategies," Alaedini said.
Importantly, the findings do not suggest that putting a child with autism on a gluten-free diet has any benefit, he added.
"Such a conclusion cannot be drawn from this particular study," Alaedini said. "By itself, the increased antibody response to gluten does not necessarily indicate sensitivity to gluten or any pathogenic [disease-causing] role for the antibodies."
The report was published in the June online issue of PLoS One.
Another expert agreed that the study findings are preliminary.
"By themselves, anti-gluten antibodies do not mean disease," explained Dr. Daniel Coury, medical director of Autism Speaks' Autism Treatment Network and chief of developmental & behavioral pediatrics at Nationwide Children's Hospital in Columbus, Ohio.
"They are part of the whole puzzle. When they occur with other abnormalities and with symptoms, we begin to get a clearer picture. It may be that this will help identify a subgroup of individuals with autism who may benefit from a specific treatment someday when we have a better understanding of just what is going on here," Coury said.
Dr. Andrew Adesman, chief of developmental & behavioral pediatrics at the Steven & Alexandra Cohen Children's Medical Center of New York in New Hyde Park, added that "this study could appear like some vindication to the many people who think that gluten is somehow involved in autism and dietary changes might be helpful. But that is not an accurate take-home message," Adesman said.
"Although increased gluten antibodies are present in children with autism and it appears they are involved in gastrointestinal problems, at this point it's hard to know what role, if any, these antibodies have in autism," he said.
Adesman noted that research into gluten-free diets for children with autism hasn't shown any benefit. "And this study doesn't reinforce any basis for dietary intervention for autistic children," he stressed.
For more on autism, visit the U.S. Centers for Disease Control and Prevention.