To review the adverse events and efficacy of hematopoietic stem cell (HSC) therapy in improving the clinical symptoms of autism spectrum disorder (ASD) in children.

Databases, which were used to search randomized controlled trials (RCTs) and/or clinical trials on HSC therapy for ASD in children, were PubMed, EMBASE, Cochrane Library, EBSCOhost, and Clinicaltrial.gov. The risk of bias was assessed with Cochrane Risk of Bias Tool 2 for RCTs and ROBINS-I for non-RCTs. The extracted data was analyzed using RStudios.

A total of 376 studies were analyzed, and six were used in this review and meta-analysis. A pooling meta-analysis found that CARS Scale means was 32.63 (95% CI [30.20 to 35.06]) and VABS change was 2.06 (95% CI [0.07 to 4.02]) in 6 months after baseline. We also found that CGI improvement was not significant in both groups (OR 0.54 (95% CI [0.07 to 4.02])). We found the most common adverse events could be categorized as non-serious, namely mild fever, nausea, vomiting, pain, and infusion-related events.

This study suggests that HSC is a relatively safe therapeutic option for children with ASD where the most common AEs that emerged are the minor ones. Despite its safety, HSC therapy did not yield a significant improvement of ASD clinical outcomes. Hence, further research and clinical trials need to be developed in order to affirm, or to refute the use of HSCs in children ASD.

Trial Registration We have already registered this review to International Prospective Registers for Systematic Reviews (PROSPERO) with the number of registration CRD42023463328.

Management options for autism spectrum disorder (ASD) include behavioral management therapy, cognitive behavioral therapy, nutritional or medication treatment, which can be combined with hematopoietic stem cell (HSC) therapy to get better results. HSC therapy is a relatively safe therapeutic option for children with ASD, where the most common adverse events that emerged are mild fever, nausea, vomiting, pain, and infusion-related events. However, HSC therapy did not show a significant and consistent improvement of ASD clinical symptoms. Hence, further research and clinical trials need to be developed in order to affirm, or to refute the use of HSCs in children ASD.

Studies need to be conducted to determine the age, disease severity, and type of autism spectrum disorder that may respond well to hematopoietic stem cell (HSC) therapy. In addition, studies on source of HSC, type of stem cells and duration of therapy are needed to determine the best therapy regimen.