[Association between HSV-2 infection and serum anti-rat brain antibodies in patients with autism]

Some cases of autism could be linked to viral infections able to induce autoimmune mechanisms directed against the encephalon. Neurothophic virus infections in animals are associated with clinical signs that are similar to those observed in neurodevelopment disorders. Thus, in this study, we determined the co-existence of antibodies against nerve tissue and viruses with neurothophic competence (HSV-1/2, Epstein-Barr-EBV, cytomegalovirus, measles and rubella) in serum of forty autistic children and forty healthy children. The presence of antibodies against nerve tissue was detected in slices of rat encephalic tissue by indirect immunofluorescence. The levels of anti-viral IgG and IgM antibodies were measured by indirect ELISA. The proportion of autistics with anti-encephalon IgG antibodies (77% anti-amygdala, 70% anti-caudate nucleus, 47.5% anti-cerebellum y anti-brain stem, 45% anti-hippocampus, 40% anti-corpus callosum and 17,5% anti-cortex) was significantly greater than that of controls (10% anti- amygdala y 5% anti- cerebellum) and was directly related to the severity of the autism. The proportion of children with positive levels (greater than 1.1.mg/dL) for anti-HSV IgM antibodies (indicative of acute infection) was significantly greater in autistics (65%) than in healthy children (17.5%). Ninety six percent of the autistics with anti-HSV antibodies also had anti-encephalon antibodies, percentage that was significantly greater than that of autistics negative to the anti-HSV-antibody (43%). In contrast, there were no significant differences for IgG and IgM antibodies for EBV, cytomegalovirus, measles and rubella. This suggests that autoimmunity against encephalic structures elicited by HSV infections could be involved in autism.