Evaluation of fractalkine and interleukin-6 plasma levels in children with Autism Spectrum Disorder

Background the etiology of autism spectrum disorder (ASD) is multifactorial with a substantial immunological component. Children with ASD show abnormal levels of cytokines which significantly contribute to core features of the disorder such as behavioral and sensory impairments. Interleukin 6 (IL-6) represents a major neuroimmune mediator commonly implicated in ASD. Alternatively, fractalkine (FKN) is a key chemokine that regulates the homeostasis of cytokines and activation of microglia. However, its role in ASD pathophysiology is still understudied. In this pilot study, we evaluated the plasma levels of FKN and interleukin-6 (IL-6) in 40 Egyptian children diagnosed with ASD in comparison to 40 age and sex-matched controls using Enzyme-linked immunosorbent assay (ELISA). Results both groups showed comparable circulating levels of FKN ( p = 0.22) and IL-6 ( p = 0.65). Receiver operating characteristic (ROC) curves showed poor diagnostic potential for FKN (AUC = 0.56, p = 0.33) and IL-6 (AUC = 0.53, p = 0.65) alike. Amongst the ASD group, FKN availability showed negligible associations with IL-6 levels, age, childhood autism rating scale, receptive expressive Arabic language scores and sensory profile. Conclusion our pilot findings indicate that impact of FKN might affect ASD at the brain level with no changes to the peripheral concentrations. Further studies are warranted to evaluate the implication of both endogenous and circulating FKN in neuroinflammation among larger cohorts of children with ASD.