Tempering expectations: considerations on the current state of stem cells therapy for autism treatment

Autism spectrum disorder (ASD) is a genetically and phenotypically heterogeneous disorder (1, 2) and it affects 1 out of 36 children (3). Due to its heterogeneity, the causes of ASD are still poorly understood and scientific research is now focused on the early identification of bio-behavioral markers to anticipate the age of diagnosis (4). Making an early diagnosis has positive implications in terms of implementation of timely evidence-based interventions and, consequently, better outcomes (5). In the complex arena of interventions for ASD, some of them are evidence-based, while others (a) are proposed without scientific basis (6), or (b) they have not yet completed the necessary steps to move from basic research to large-scale clinical application but are transferred to clinical practice. Regarding option b, in recent years, we have witnessed a worrying increase in institutes that proposing to families to treat ASD with stem cells from various sources, including those obtained from cord blood (7). The alarming aspect of this potential therapeutic proposal is the promise of significant clinical improvements in children who undergo this treatment. These institutes, which are often located in countries with low medical standards, are not proposing a research trial but the use of stem cells as a therapeutic option already validated by basic research. However, to date, can we say that the use of stem cells is an evidence-based treatment? The answer is no, and we will try in the following lines to explain the reasons for this negative answer.