Assessment of Protein Oxidation-Related Biomarkers in Children with Autism Spectrum Disorder

Abstract

This study aimed to investigate the plasma levels of nitric oxide (NO) and the plasma protein oxidation-related biomarker [3-nitrotyrosine (3-NT), and protein carbonyl (PC)] in ASD children and their correlation to the severity of symptoms. This study included 40 Egyptian childrenwith ASD, divided into 3groups mild (18 children), moderate (14 children), and severe (8 children) ASD children groups, and 40 age-and gender- matched controls with age ranged from 3 to 5 years (mean 3.5 ±1.1 years). Plasma from children and control subjects were investigated for NO, 3-NT and PC levels. A significant increase in plasma NO, 3-NT and PC levels (98%, 33.5% and 41%, respectively; p<0.001) was observed in all ASD children compared to controls. The levels of NO, 3-NT and PC showed the significant highest concentration in plasma of severe ASD children group (180%, 77%, and 88%, respectively; p<0.001) compared to moderate and mild groups, respectively. These parameters were also positively correlated to the severity of ASD symptoms (CARS score). Results obtained from Receiver Operating Characteristic (ROC) curves indicate that the selected parameters showed a very high sensitivity (~100%) and specificity (~100%) in all ASD children. Linear regression analysis confirmed that higher levels of NO, 3-NT and PC can be used to predict social and cognitive impairment in ASD children. Inconclusion: Our results supportthe notion that oxidative stress may play a central role in the pathogenesis of ASD. Moreover, the strong association of the measured biomarkers with the severity of ASD

symptoms suggest that the marked increase in the studied biomarkers could be potentially utilized as peripheral biomarkers of ASD and helped in the early detection of ASD.

Keywords: Autism Spectrum disorder, Oxidative stress, Protein oxidation biomarkers, Nitric oxide, 3-nitrotyrosine, Protein carbonyl.