The Possible Association between Elevated Levels of Blood Mercury and the Increased Frequency of Serum Anti-myelin Basic Protein Auto-antibodies in Autistic Children

Background: Autism can occur as a result of a complex interaction between environmental factors and genetic predisposition. Mercury is a neurotoxicant and it is one of the main environmental triggers for autoimmunity. The underlying pathogenic mechanism in autoimmune disorders is the formation of auto-antibodies. Brain specific autoantibodies are elevated in a subgroup of autistic children. We are the first to study the relation between blood mercury levels and the seropositivity of anti-myelin basic protein (anti-MBP) autoantibodies in autistic children. Methods: Blood mercury levels were measured, by atomic absorption spectrometry, and serum levels of antiMBP auto-antibodies were measured, by ELISA, in 100 children with autism aged between 5-12 years and 100 healthy-matched control children. Results: Serum levels of blood mercury were significantly higher in autistic children than healthy controls (P<0.001). Increased levels of blood mercury were found in 48% of autistic patients. In addition, 72% of autistic children had positive results of serum anti-MBP auto-antibodies. There was a significant positive association between the elevated levels of blood mercury and the positivity of serum anti-MBP auto-antibodies in autistic children (P<0.001). Conclusions: Blood mercury levels were elevated in some autistic children and they were significantly associated with the production of serum anti-MBP auto-antibodies in a group of autistic children. Further research is warranted to determine if the production of brain auto-antibodies is triggered by environmental mercury exposure in autistic children. The possible therapeutic role of mercury chelators in autistic children should be also studied.