Anti-metallothionein IgG and levels of metallothionein in autistic families.

Metallothioneins (MTs) are a family of small proteins containing 61-68 amino acids with an unusually high concentration of cysteine. MT-1, the most functional and active MT in humans, has the ability to react with and enhance the detoxification of a number of metals including zinc, mercury, copper and cadmium. MT dysfunction may result, then, in many of the aetiological syndromes observed in autistic children, such as the leaky gut. It has been proposed that allergic autoimmune reactions occurring after exposure to heavy metals, may contribute to some symptoms associated with autism. Therefore abnormalities in MT concentration and/or structure, as well as the presence of anti-MT antibodies, may be associated with autism. We used direct ELISAs to quantitate the concentration of serum anti-metallothionein IgG in 66 individuals (parents and children) from 14 families with autistic children, as well as 11 controls from families with no history of autism. We measured the concentration of serum metallothionein in 39 of the above family members from 8 families. Our results indicate that a significantly high number (23 of 66) of autistic family members had high levels of anti-metallothionein IgG, when compared to controls (1 ) and the production of these antibodies correlated with levels of metallothionein, suggesting that the production of these antibodies is inherited. However, the presence of these antibodies does not correlate with autism, types of autism, including regression, or demographics such as allergies, respiratory problems or GI disease. This suggests that the presence of anti-metallothionein antibodies is not causative to autism and may be the result of other immunological pathology seen in many autistics.