Abstract
BACKGROUND: Autism spectrum disorder (ASD) is a complex neurodevelopmental condition for which there are no definitive medications targeting core symptoms. Growing evidence indicates that individuals with ASD exhibit immune dysfunction and evidence of peripheral and central inflammation. Immunotherapy interventions have shown promise in addressing this dysregulation. Notably, low-dose Interleukin-2 (Ld IL-2), an established treatment for certain autoimmune diseases, represents a potential therapeutic approach. Our study aims to investigate the association between Ld IL-2-induced immune modulation and behavioral improvements in children with ASD. This research may offer novel insights into potential treatment strategies for ASD. CASE PRESENTATION: In our previously completed single-arm, self-controlled clinical study (data unpublished), 24 ASD children with immune abnormalities received Ld IL-2 treatment, all of whom showed varying degrees of symptom improvement. This paper presents case reports of four ASD children who demonstrated marked clinical improvement and substantial correction of immune imbalance following treatment. The average age of 4 participants was approximately 6 years old, comprising two boys and two girls. Assessments using the Childhood Autism Rating Scale(CARS), Aberrant Behavior Checklist (ABC), Autism Treatment Evaluation Checklist (ATEC), Krug's Autism Behavior Scale (CABS), Hospital Anxiety and Depression Scale (HADS), and Caregiver Strain Questionnaire (CGSQ)revealed substantial behavioral improvements and no adverse events. Improvements persisted for three months post-treatment, with notable progress in Speech/Language/Communication and body/health/behavior domains. According to caregivers, there has been a observed improvement in the subjects' sleep quality, accompanied by a gradual restoration of overall physical health. Immune testing in the four pediatric patients revealed a marked decrease in both the proportion of Type 1 cytotoxic T cells (Tc1) and the Tc1/Regulatory T cell ratio. CONCLUSIONS: Our findings in these four cases describe an association between Ld IL-2 treatment and observed improvements in ASD symptoms, potentially linked to immune modulation.