Cell Therapies for Autism Spectrum Disorder Based on New Pathophysiology: A Review

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder characterized by difficulties in social communication, repetitive behaviors, and restricted interests, with onset early in life. The prevalence of ASD has increased worldwide in the last two decades. However, there is currently no effective therapy for ASD. Therefore, it is important to develop new strategies for ASD treatment. Evidence for the relationship between ASD and neuroinflammation, ASD and microglia, and ASD and glucose metabolism has increased rapidly in recent decades. We reviewed 10 clinical studies on cell therapies for individuals with ASD. Almost all studies showed good outcomes and no remarkable adverse events. Over the past decades, the neurophysiological characteristics of ASD have been shown to be impaired communication, cognition, perception, motor skills, executive function, theory of mind, and control of emotions. Recent studies have focused on the roles of immune pathology, such as neuroinflammation, microglia, cytokines, and oxidative stress, in ASD. We also focused on glucose metabolism in patients with ASD. The significance of gap junction–mediated cell–cell interactions between the cerebral endothelium and transplanted cells was observed in both bone marrow mononuclear cells and mesenchymal stromal cells transplantation. Owing to the insufficient number of samples, cell therapies, such as umbilical cord blood cells, bone marrow mononuclear cells, and mesenchymal stromal cells, will be a major challenge for ASD. As a result of these findings, a new paradigm for cell therapy for autism may emerge.