Oxidative Stress and Dynamic Thiol/Disulfide Homeostasis in Autism: A Focus on Early Childhood

Abstract Autism spectrum disorder (ASD) is a complex neurodevelopmental condition with multifactorial etiopathogenesis, where oxidative stress (OS) has been implicated as a key contributing factor. This study aimed to evaluate the plasma dynamic thiol/disulfide homeostasis (DTDH) parameters—a relatively novel OS biomarker—alongside classical OS biomarkers, including total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), glutathione, and glutathione peroxidase (GPx), in preschool children diagnosed with ASD. A total of 49 children with ASD and 31 age- and sex-matched typically developing children between the ages of 2 and 6 years were included. In addition to sociodemographic data collection, the Childhood Autism Rating Scale (CARS) and Clinical Global Impression-Severity Scale (CGI-S) were administered to assess autism severity. Blood samples were analyzed using automated spectrophotometric techniques to determine OS biomarkers. The results demonstrated that DTDH parameters and classical OS markers exhibited parallel changes; however, no statistically significant differences were detected between the ASD and control groups across all OS markers. Furthermore, no significant association was found between OS biomarkers and autism severity. Moreover, we intentionally restricted our sample to a younger age group to enable a focused examination of OS dynamics during early developmental stages. This study underscores the potential impact of age as a critical determinant in OS-related alterations in autism and highlights the need for further age-stratified investigations to elucidate the role of OS in ASD pathophysiology and its potential diagnostic relevance.