A possible association between elevated serum levels of brain-specific auto-antibodies and reduced plasma levels of docosahexaenoic acid in autistic children.

Polyunsaturated fatty acids (PUFAs) are not only essential for energy production, but they also exhibit a range of immunomodulatory properties that progress through T cell mediated events. Autoimmunity may have a pathogenic role in a subgroup of autistic children. This study is the first to investigate the relationship between serum levels of anti-myelin basic protein (anti-MBP) brain-specific auto-antibodies and reduced plasma levels of PUFAs in autistic children. Plasma levels of PUFAs (including linoleic, alphalinolenic, arachidonic "AA" and docosahexaenoic "DHA" acids) and serum anti-MBP were measured in 80 autistic children, aged between 4 and 12 years, and 80 healthy-matched children. Autistic patients had significantly lower plasma levels of PUFAs than healthy children. On the other hand, ω6/ω3 ratio (AA/DHA) was significantly higher in autistic patients than healthy children. Low plasma DHA, AA, linolenic and linoleic acids were found in 67.5%, 50%, 40% and 35%, respectively of autistic children. On the other hand, 70% of autistic patients had elevated ω6/ω3 ratio. Autistic patients with increased serum levels of anti-MBP auto-antibodies (75%) had significantly lower plasma DHA (P<0.5) and significantly higher ω6/ω3 ratio (P<0.5) than patients who were seronegative for these antibodies. In conclusions, some autistic children have a significant positive association between reduced levels of plasma DHA and increased serum levels of anti-MBP brain-specific auto-antibodies. However, replication studies of larger samples are recommended to validate whether reduced levels of plasma PUFAs are a mere association or have a role in the induction of the production of anti-MBP in some autistic children.