Enrichment of Elevated Plasma F2t-Isoprostane Levels in Individuals with Autism Who Are Stratified by Presence of Gastrointestinal Dysfunction
PLoS ONE 8(7): e68444.
Gorrindo P, Lane CJ, Lee EB, McLaughlin B, Levitt P (July 3, 2013)
Funding: This work was supported in part by National Institutes of Health awards National Institute of Child Health and Human Development R21HD065289 (PL), National Institute of General Medical Sciences T32GM07347 for the Vanderbilt Medical Scientist Training Program (PG), National Center for Research Resources TL1RR024978 (PG), and National Center for Advancing Translational Sciences UL1TR000445 for the Vanderbilt Institute for Clinical and Translational Research. Additional support was provided by the Marino Autism Research Institute, the Pediatric Clinical Research Center at Vanderbilt University, The Scott Family Foundation, and the Vanderbilt Autism Treatment Network Site, a program funded by Autism Speaks.
Abstract
Etiology is unknown in the majority of individuals with autism spectrum disorder (ASD). One strategy to investigate pathogenesis is to stratify this heterogeneous disorder based on a prominent phenotypic feature that enriches for homogeneity within population strata. Co-occurring gastrointestinal dysfunction (GID) characterizes a subset of children with ASD. Our current objective was to investigate a potential pathophysiological measure to test the hypothesis that children with both ASD and GID have a more severe metabolic dysfunction than children with ASD-only, given that the highly metabolically active brain and gastrointestinal system may additively contribute measurable impairment. Plasma levels of F2t-Isoprostanes (F2-IsoPs), a gold standard biomarker of oxidative stress, were measured in 87 children in four groups: ASD-GID, ASD-only, GID-only and Unaffected. F2-IsoP levels were elevated in all 3 clinical groups compared to the Unaffected group, with the ASD-GID group significantly elevated above the ASD-only group (mean, SD in pg/mg: ASD-GID 53.6, 24.4; ASD-only 36.5, 13.3; p = 0.007). Adjusting for age, sex, and triglyceride levels, F2-IsoP levels remained significantly different between study groups, with a moderate effect size of ηp2 = 0.187 (p = 0.001). Elevation in peripheral oxidative stress is consistent with, and may contribute to, the more severe functional impairments in the ASD-GID group. With unique medical, metabolic, and behavioral features in children with ASD-GID, the present findings serve as a compelling rationale for both individualized approaches to clinical care and integrated studies of biomarker enrichment in ASD subgroups that may better address the complex etiology of ASD.
