OBJECTIVE: To explore the impact of auditory integrative training (AIT) on the inflammatory biomarker transforming growth factor (TGF)-beta1 and to assess its effect on social behavior in children with autism spectrum disorder (ASD). SUBJECTS AND METHODS: In this cross-sectional study, 15 patients (14 males and 1 female) with ASD aged 3-12 years were recruited. All were screened for autism using the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Plasma levels of TGF-beta1 were measured in all patients using a sandwich enzyme-linked immunoassay (ELISA) immediately and 1 and 3 months after the AIT sessions. Pre- and post-AIT behavioral scores were also calculated for each child using the Childhood Autism Rating Scale (CARS), the Social Responsiveness Scale (SRS), and the Short Sensory Profile (SSP). Data were analyzed using the Statistical Package for the Social Sciences (SPSS 21.0 for Windows). RESULTS: Plasma levels of TGF-beta1 significantly increased to 85% immediately after AIT (20.13 +/- 12 ng/mL, p < 0.05), to 95% 1 month after AIT (21.2 +/- 11 ng/mL, p < 0.01), and to 105% 3 months after AIT (22.25 +/- 16 ng/mL, p < 0.01) compared to before AIT (10.85 +/- 8 ng/mL). Results also revealed that behavioral rating scales (CARS, SRS, and SSP) improved in terms of disease severity after AIT. CONCLUSION: Increased plasma levels of TGF-beta1 support the therapeutic effect of AIT on TGF-beta1 followed by improvement in social awareness, social cognition, and social communication in children with ASD. Furthermore, TGF-beta1 was associated with severity in all scores tested (CARS, SRS, and SSP); if confirmed in studies with larger sample sizes, TGF-beta1 may be considered as a marker of ASD severity and to assess the efficacy of therapeutic interventions.