The relationship between perceived immune functioning and autism spectrum disorder scores in healthy young adults

Abstract

Introduction: Altered immune functioning has been demonstrated in individuals with autism spectrum disorder (ASD) [1,2]. Skewed cytokine profiles have been linked to ASD, because of their ability to interact with neural systems of development and maintenance [1,2]. In this context, it has been argued that high fetal levels of testosterone suppress immune functioning, and at the same time increase the risk of developing ASD [3]. The current study explores the relationship between perceived immune functioning and experiencing ASD symptoms in healthy young adults. Aim of the study: To examine the relationship between ASD and the perceived immune functioning. Methods: Students from Utrecht University were asked to complete a survey on autism and immune functioning. The 19- item Immune Function Questionnaire (IFQ) was completed [4] to assess perceived immune functioning. The overall IFQ-score ranges from 0 to 76, with higher scores implying worse immune functioning. The Dutch translation of the Autism-Spectrum Quotient (AQ) [5] was completed to examine variation in autistic traits. The total AQ score was based on the 4-point Likert scale scores (ranging from “definitely agree” to “definitely disagree”), with a higher sum score implying endorsing more autism characteristics. This questionnaire consists of 5 subscales, each assessing a different domain of ASD, covering 'social insights and behavior', 'difficulties with change', 'communication', 'phantasy and imagination', and 'detail orientation'. Correlational analyses were conducted to examine the relationship between ADS and its domains, and the IFQ immune score. Results: N= 259 participants completed the AQ questionnaire. Significant correlations were found between the IFQ immune score and the total AQ score (r = 0.169, p = 0.007), and the subscales 'difficulties with change' (r = 0.185, p = 0.003) and 'communication' (r = 0.146, p = 0.018). In women, the IFQ immune score correlated significantly with the total AQ score (r = 0.223, p = 0.010), and the subscale 'social insights and behavior' (r = 0.190, p = 0.025). In men, significant correlations were found between the IFQ immune score and the total AQ score (r = 0.196, p = 0.033), and the subscales 'difficulties with change' (r = 0.231, p = 0.011) and 'communication' (r = 0.208, p = 0.022). Conclusions: Our findings confirm the relationship between immune functioning and several aspects of autism spectrum disorder. The association between total AQ score and the level of immune functioning was significant in both men and women. Although the observed associations are modest, it should be taken into account that the current sample comprised healthy young volunteers. Interestingly, regarding specific ASD domains, although in both men and women an association was found with 'difficulties with change', associations with other ASD domains seem to be more gender specific. The latter warrants further research, preferably in patients formally diagnosed with ASD.