Brain-Derived Neurotrophic Factor and Insulin-Like Growth Factor 1 Serum Levels in Naive and Medicated Subjects with Autism (v1.0)

Brain-derived neurotrophic factor (BDNF) and insulin-like growth factor 1 (IGF-1) promote the development and maintenance of neural circuits. Alterations in these factors might contribute to autism spectrum disorder. We asked whether serum BDNF and IGF-1 levels are altered in an autistic population compared to controls. We measured serum BDNF and IGF-1 immunoreactive protein in boys and girls ages 5 to 15 years old with mild to moderate autism and non-autistic controls by ELISA. IGF-1 was increased in serum of subjects with autism spectrum disorder compared to controls and was correlated with behavior (CARS) scores. Serum BDNF levels were elevated only in unmedicated subjects with autism spectrum disorder compared to controls. These data support the involvement of BDNF and IGF-1 in the pathogenesis of autism.