The Status of Biomarker Research for Autism Spectrum Disorders: Recent Progress and Future Directions

Background: Autism spectrum disorders (ASD) are complex and heterogeneous with a spectrum of diverse symptoms and co-morbidities. A reliable biomarker for ASD may help provide invaluable insight to elucidate mechanisms of action that underlie the causes of autism, as well as provide possible therapeutic targets or for monitoring of treatment. Mounting evidence from a number of disciplines suggests a link between immune dysfunction and ASD. Although the causes of ASD have yet to be identified, genetic studies have uncovered many candidate genes relating to immune regulation that are altered in ASD, while peripheral markers of immune activity are often associated with greater impairments in behaviors. Epidemiological and animal studies also suggest a relationship between maternal immune disturbances during pregnancy and changes in neurodevelopment. 

Objectives: This presentation will summarize the current status of biomarker research for ASD, primarily focusing on immune parameters as targets of emerging interest for biomarker discovery. Specifically, this presentation will: (1) describe the role of the immune system in ASD with respect to the development of blood biomarkers; (2) summarize different examples of immune based biomarkers for ASD; (3) provide rationale for selected biomarkers that could guide potential treatments, and; (4) discuss emerging targets as putative biomarkers.

Methods: Decades of research have identified numerous systemic and cellular immune abnormalities in individuals with ASD and their families, providing compelling targets to explore as biomarkers. The changes in immune cell number, differences in cytokine and chemokine production, presence of brain-reactive antibodies and alterations of cellular function at rest and in response to immunological challenge in ASD will be described. While changes in immune responses may be associated with increasing impairment in behaviors that are core features of ASD, much remains to be understood about the precise mechanism by which the immune system alters neurodevelopment and to what extent it is involved in the pathogenesis of ASD. This presentation will provide a critical overview regarding putative immune biomarkers that are currently being researched for ASD.

Results: At the conclusion of this presentation, attendees will understand the role of the immune system in ASD with respect to the development of putative blood biomarkers.

Conclusions:   With estimates of ASD as high as 1% of children, ASD is a major public health issue. Improvements in our understanding of the interactions between the nervous and immune system during early neurodevelopment and how this interaction is different in ASD will have important implications for the development of potential biomarkers for ASD, as well as therapeutic implications with wide ranging benefits.