Autism: maternally derived antibodies specific for fetal brain proteins.

Autism is a profound disorder of neurodevelopment with poorly understood biological origins. A potential role for maternal autoantibodies in the etiology of some cases of autism has been proposed in previous studies. To investigate this hypothesis, maternal plasma antibodies against human fetal and adult brain proteins were analyzed by western blot in 61 mothers of children with autistic disorder and 102 controls matched for maternal age and birth year (62 mothers of typically developing children (TD) and 40 mothers of children with non-ASD developmental delays (DD)). We observed reactivity to two protein bands at approximately 73 and 37kDa in plasma from 7 of 61 (11.5%) mothers of children with autism (AU) against fetal but not adult brain, which was not noted in either control group (TD; 0/62 p=0.0061 and DD; 0/40 p=0.0401). Further, the presence of reactivity to these two bands was associated with parent report of behavioral regression in AU children when compared to the TD (p=0.0019) and DD (0.0089) groups. Individual reactivity to the 37kDa band was observed significantly more often in the AU population compared with TD (p=0.0086) and DD (p=0.002) mothers, yielding a 5.69-fold odds ratio (95% confidence interval 2.09-15.51) associated with this band. The presence of these antibodies in the plasma of some mothers of children with autism, as well as the differential findings between mothers of children with early onset and regressive autism may suggest an association between the transfer of IgG autoantibodies during early neurodevelopment and the risk of developing of autism in some children.