VEGF, IGF-1 and FGF-2 Serum Levels in Children and Adolescents with Autism Spectrum Disorder with and without Bipolar Disorder

Purpose: To investigate serum levels of VEGF, IGF-1 and FGF-2, and relationships with several clinical characteristics in children and adolescents with autism spectrum disorder (ASD) with and without bipolar disorder (BD). Method: 40 subjects with ASD + BD as study group, and 40 subjects with ASD as control group were included. Serum levels of VEGF, IGF-1, and FGF-2 were measured using commercial enzyme-linked immunosorbent assay kits. Results: The study group was significantly higher than the control group in terms of ASD severity, self-harming behavior and sleep disturbance. Serum VEGF and FGF-2 levels were significantly higher in the ASD + BD group than in the control group. There was no significant difference in serum IGF-1 levels between the two groups. There was no correlation between VEGF, IGF-1 and FGF-2 serum levels and ASD severity in the study group. However there was a negative correlation between VEGF levels and age at first diagnosis of BD, and a positive correlation between IGF-1 levels and the number of bipolar episodes in the study group. Conclusion: Growth factors like VEGF and FGF-2 may be potential biomarkers of bipolar disorder in young subjects with ASD. Given the difficulty of clinical management of BD in young subjects with ASD, potential biomarkers would help clinicians in the diagnosis and follow up of BD in this special population. Further research is needed whether VEGF and FGF-2 can be potential biomarkers in the clinical management of young subjects with ASD and BD.