Urinary levels of neopterin and biopterin in autism.

The pterins, neopterin and biopterin, occur naturally in body fluids including urine. It is well established that increased neopterin levels are associated with activation of the cellular immune system and that reduced biopterins are essential for neurotransmitter synthesis. It has been suggested that some autistic children may be suffering from an autoimmune disorder. To investigate this further we performed high performance liquid chromatography analyses of urinary pterins in a group of pre-school autistic children, their siblings and age-matched control children. Both urinary neopterin and biopterin were raised in the autistic children compared to controls and the siblings showed intermediate values. This supports the possible involvement of cell-mediated immunity in the aetiology of autism.