Endothelial antibody levels in the sera of children with autism spectrum disorders.

BACKGROUND The neurobiological basis of autism remains poorly understood. We hypothesized that endothelial antibodies may be associated with the pathophysiology of autism and may predict intellectual/social developmental abnormalities. METHODS Plasma levels of antiendothelial cell antibodies (AECAs) were measured by enzyme-linked immunosorbent assay in autistic children (n = 55) and age-matched healthy controls (n = 25). RESULTS The serum level of AECAs in children with autism {n = 55, 306.4 ± 45.6 pg/mL [mean ± standard error of the mean (SEM)]} was higher (two-tailed Student t test: p = 0.05) than that of healthy controls [n = 25, 209.6 ± 24.6 pg/mL (mean ± SEM)]. Children with severe autism exhibited significantly higher AECAs than healthy controls (diagnoses of autistic children based on the Childhood Autism Rating Scale score, >40) [n = 20, 369.6 ± 65.6 pg/mL (mean ± SEM)] (p = 0.03). Disease severity and the Childhood Autism Rating Scale score, which represent stereotyped patterns of behavior in children with autism, were positively correlated (r(2) = 0.27, p = 0.05). CONCLUSION Elevated AECA serum levels may be implicated in the pathogenesis of autism. However, these data should be interpreted with caution until further investigations are performed using larger sample sizes to determine whether the increase in serum AECA levels is a mere consequence of autism or it plays a pathogenic role in the disease.