Abstract
AIM: This study aimed to explore the relationship between self-esteem and tumor necrotic factor-alpha (TNF-α) expression in individuals with autism spectrum disorder (ASD). Self-esteem was assessed using the Contingencies of Self-Worth (CSW) scale, with a focus on external and internal contingencies, and TNF-α expression was measured, given its association with both ASD pathophysiology and self-esteem in prior studies. METHODS: We enrolled 51 high-functioning individuals with ASD and 34 typically developed (TD) individuals. Self-esteem was assessed using the Japanese version of the CSW scale, which evaluates seven domains, and the Personal Sense of Power. TNF-α expression in plasma was quantified via ELISA. Correlations of CSW scores and the Personal Sense of Power with TNF-α levels were analyzed using multiple regression models adjusted for confounding factors such as age, sex, education level, and autistic symptoms. RESULTS: In ASD individuals, TNF-α expression was significantly negatively correlated with the external CSW domain of others' approval and showed a trend toward negative correlations with appearance and relationship harmony. These correlations were not observed in the TD individuals. Likewise, the Personal Sense of Power within family settings showed a trend toward positive correlations with TNF-α expression in ASD individuals, but not in TD individuals. DISCUSSION: This study highlights the implication of TNF-α levels in the self-esteem of ASD individuals, particularly in interpersonal relationships. Lower TNF-α expression was associated with higher self-esteem in social contexts, independent of the severity of autistic symptoms. These findings suggest a biological link between inflammatory pathways and self-esteem in ASD, contributing to a deeper understanding of the interplay between immune function and psychological well-being in this population.