Increased inflammatory cytokines in the temporal cortex in autism spectrum disorder

Alterations in immune and neuroinflammatory processes are evident in neurodevelopmental disorders such as autism spectrum disorders (ASD). While prior studies using cerebrospinal fluid and plasma/serum have identified differences in cytokine levels in ASD when compared with controls, specific changes in postmortem human brain tissue remains poorly characterized. The superior temporal gyrus (STG) is involved in social communication and sensory processing, and is affected in ASD, making it a relevant region for investigating immune-related differences that has not been previously studied. Neuroimmune profiles were measured in STG tissue from 46 postmortem cases: ASD (n = 17), and neurotypical controls (n = 29). Fresh-frozen samples were collected using biopsy punches, and cytokines, chemokines, and growth factors were quantified using multiplexed bead immunoassays. In ASD cases, there were significantly increased levels of inflammatory cytokines in IL-1α, IL-8, IL-18, FLT-3L, FGF-2, G-CSF, M-CSF, MCP3, PDGF-AA and GROa compared to controls. In contrast, there was a significant decrease in RANTES, IFNα2 and IL-4 cytokine levels in ASD. Overall, ASD presented a distinctive STG cytokine profile with increased pro-inflammatory cytokine levels in the absence of an immune regulatory balance. These data highlights that unique neuroimmune pathways occur in neurodevelopmental disorders such as ASD offering insights into potential therapeutic targets.