Oxidative Stress in Asperger Syndrome and Healthy Adolescents

Background: An adequate equilibrium between the production of reactive oxygen species (ROS) and the antioxidant capacity of the cell plays an important role in cerebral development and differentiation (Fantel and Person 2002; Gorman et al. 2000). In Autistic children, an increase in ROS and decrease in plasmatic antioxidant activity has been shown in comparison with healthy controls (Sogut, 2003, Zoroglu 2003, Zoroglu 2004, James 2004, Chauhan 2004; Chauhan 2006 for a review). Objectives: We aim to study the oxidative stress status in a subgroup of ASD adolescents without mental retardation, all with Asperger syndrome, and compare it with a group of healthy controls.We hypothesized that an excessive oxidative stress will be present in Asperger syndrome patients in comparison with control subjects.

Methods: 27 children and adolescents (7 to 17 years old) with Asperger syndrome, and 30 healthy controls, matched for sex and age, were recruited for this study. Diagnosis of Asperger Syndrome was made by DSM-IV criteria, Gillberg criteria and ADOS evaluation when needed. We selected healthy controls from publicly-funded schools with characteristics similar to those attended by patients in the community. Plasma Total Antioxidant Status (TAOS), which provides information on overall systemic antioxidant function was measured in .two consecutive analyses (separated by 8 weeks), and the mean between both determinations was compared between the two groups. Catalase, superoxido dysmutase ; gluthation peroxidase enzymes and plasma gluthation were also determined. All determinations were made by spectrophotometry.Results: Mean total antioxidant status was lower in adolescents with and Asperger syndrome than in controls (1.158 vs 1.272, p=0.047). No differences in any of the antioxidant enzymes or the glutathion was found.

Conclusions: Oxidative metabolism disequilibrium may be an intermediate pathophysiological pathway not only in severe, regressive or retarded autistic individuals, but also in Asperger individuals. This finding supports the altered detoxifying system theories of ASD.