There are some caveats, however, Castagnola said. For starters, autistic patients typically aren't cooperative. And it's not clear what treatment would follow a positive diagnosis.
Future research is needed to determine the connection between test results and signs of autism, Castagnola said.
Zimmerman, who had no role in the study but is familiar with its findings, cautioned that autism comes in many forms, and a test of proteins in saliva "might not correlate specifically in certain types of patients with autism and might not be consistent over time."
Still, the new study offers "exciting possibilities" for understanding autism through the cells and chemical processes in the body, he said.
To learn more about autism, visit Autism Speaks.
SOURCES: Andrew Zimmerman, M.D., pediatric neurologist and director, medical research, Center for Autism and Related Disorders, Kennedy Krieger Institute, Baltimore; Massimo Castagnola, researcher, Università Cattolica, Rome; Jan. 2, 2009, Journal of Proteome Research
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