The association between levels of inflammatory markers in autistic children compared to their unaffected siblings and unrelated healthy controls

Background/aim: Autism spectrum disorder (ASD) describes a range of neurodevelopmental disabilities that impair behavior and communication. Although it is relatively prevalent, the pathophysiology is still subject to speculation and debate. The aim of this study is to identify a possible association between interleukin-6, -8, -9, and -10 and tumor necrosis factor alpha (TNF-α) in autism among Jordanian children by comparing the plasma levels of these cytokines in autistic children with those of their unaffected siblings and unrelated healthy controls. Materials and methods: In this study, 80 Jordanian children under the age of 12 with diagnosed autism were selected. For comparison, 51 unaffected siblings and 86 unrelated healthy controls were also recruited. Venous blood was collected and interleukin levels in all three groups were investigated. Results: Interleukin-6 was found to be significantly higher in the plasma of both autistic children and their siblings compared with the unrelated healthy control group (P < 0.05). As for interleukin-8 and TNF-α, plasma levels were significantly higher exclusively in autistic children compared to their siblings and unaffected control subjects (P < 0.001, P < 0.001). There was no significant difference between plasma levels of the previously mentioned cytokines in the siblings and the unrelated control group. As for interleukin-9 and interleukin-10, no significant differences were found between all three groups (P = 0.15, P = 0.35). Conclusion: We found that interleukin-8 and TNF-α were exclusively elevated in autistic Jordanian children, while interleukin-6 was elevated in both autistic children and their siblings, potentially dismissing its significance. These results may lead to a better understanding of the disorder's pathophysiology, early testing, and diagnosis.